| 00:03 | This is lecture 15 of neuroscience and continue talking about major parts of the |
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| 00:12 | and functions of the different parts of brain. So we over viewed in |
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| 00:19 | brief the major divisions of the spinal . The brain stem which is subdivided |
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| 00:25 | the to the closest to the spinal , the ponds, the midbrain on |
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| 00:32 | back of the brain stem. You cerebellum, you have cerebral hemispheres within |
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| 00:39 | sub cortical. You have diane cephalon is thalamus and hypothalamus. And you |
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| 00:46 | this specialized nuclei basal ganglia, hippocampus the amygdala that we discussed. So |
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| 00:54 | of these are great labeling questions for different parts, major parts of the |
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| 01:00 | . N. S and their And we ended last lecture talking about |
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| 01:08 | cephalon and in particular the thalamus a bit about hypothalamus and super charismatic |
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| 01:15 | And what we learned about thalamus is of the sensor information. Sound, |
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| 01:23 | , touch is going to come in the Solomon's before it goes into the |
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| 01:30 | cortex from the entry of that signal the periphery whether it's a coke leah |
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| 01:37 | the retina to the time it gets the thalamus. There's some processing that |
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| 01:43 | place in the periphery in the cochlear or in the retina there's further modulation |
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| 01:49 | that incoming external sensory stimulus such as information from the retina at the level |
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| 01:56 | the thalamus and thalamus will contain nuclei specifically handle different functions. So retina |
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| 02:04 | project the lateral nucleus nucleus of the clia will project into the media the |
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| 02:13 | of the thalamus by project. I they will send their external projections and |
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| 02:17 | will form synopsis from the retina in thalamic regions and information coming from uh |
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| 02:25 | parts like the dorsal column, nuclei the spinal cord will have their own |
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| 02:31 | . Central, posterior lateral nuclear. it's really a sophisticated collection of nuclei |
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| 02:36 | are dedicated to specific functions to communicate information to the quartet and not just |
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| 02:43 | relay that information would rather than a and modulate, adjust the sensory input |
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| 02:50 | is coming in that goes into the and cortex has the ability to adjust |
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| 02:56 | us by responding back, sending the from the cortex back into the colonists |
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| 03:03 | . It's more of the autonomic and bodily function control. Uh It's involved |
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| 03:09 | the neuro endocrine control and visceral And superga asthmatic nucleus is the master |
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| 03:16 | clock regulator or the circadian rhythm Which is your day and night |
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| 03:24 | Or wake and sleep rhythms as other of of the brain and the structures |
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| 03:32 | we're talking about. Uh And these are all very good labeling questions. |
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| 03:37 | example, this is the corpus callosum you saw earlier. This would be |
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| 03:42 | major fiber bundle that inter connects the hemispheres. Again when I say fiber |
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| 03:48 | . Axonal fiber bundles and outputs and that are gonna be going both |
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| 03:55 | Okay now here you see you have sky as um off the chi as |
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| 04:01 | super charismatic nucleus would be located very to the optic eye. ASM you |
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| 04:07 | see how small the olfactory ball does the human brain compared to the rest |
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| 04:12 | the size of the brain. Uh can see another structure that we discussed |
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| 04:18 | which is uh your emotional and fear center uh and hippocampus which is involved |
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| 04:28 | semantic memory as we discuss previously. hippocampus is also involved in spatial memory |
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| 04:37 | is remembering spaces and remembering directions in way how to navigate navigational spatial memory |
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| 04:45 | a way. So not just names and places but also spaces. |
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| 04:50 | you may cerebellum which is attached on back of the brain. If you |
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| 04:59 | to remove the cerebellum it's attached onto cerebellum, pete uncle. So if |
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| 05:06 | were to cut the cerebellum from the you would expose the cerebellum, |
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| 05:11 | uncles sarah Palin has left cerebellum the right celebrates cerebellum hemisphere in the |
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| 05:20 | . There is a verma's cerebellum. in our discussions it's responsible for control |
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| 05:31 | appropriate reception. It's responsible for procedural and it's responsible for adjustment and fine |
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| 05:41 | of the motor outputs and mod outfits the cortex and route into the |
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| 05:48 | So tuning some of these motor patterns get initiated by basil ganglia as we |
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| 05:56 | and get communicated to the primary motor to inform downstream the spinal cord motor |
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| 06:04 | to contract the muscles to produce the that we want to produce. Now |
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| 06:10 | on the obviously on the back because is on the back. So now |
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| 06:15 | looking from, from the dorsal you have the structure that we refer |
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| 06:23 | last lecture that is called corporate quadra and is comprised of the left and |
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| 06:30 | , superior curricula sauce and left and , inferior curricula sauce. So superior |
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| 06:40 | is responsible for processing reflexive eye movement psychotic eye movement. Kind of a |
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| 06:47 | like eye movement. And inferior caligula is involved in processing the auditory |
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| 06:56 | And we will look at the exact for the visual pathways and for the |
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| 07:02 | pathways very soon in this course. you will see these structures come up |
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| 07:08 | as we discuss the systems and you see the pioneer body sitting here superior |
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| 07:18 | the superior curricula sauce and superior So superior to the inferior curricula |
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| 07:24 | And inferior curricula is inferior to the curricula, suspects underneath, on top |
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| 07:30 | underneath if you may. And once this is the fourth ventricle going into |
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| 07:38 | spinal canal and the spinal cord where have the supply of the super spinal |
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| 07:44 | . Yeah, uh is responsible for auditory information. It's well for the |
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| 08:01 | , it's more of the psychotic eye . That's reflexive for the auditory you |
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| 08:07 | have a flow through the real auditor processing the major flow through a major |
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| 08:15 | information processing into your curriculum but not the visual, the visual and the |
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| 08:20 | will go into the, into the and that's why I said don't worry |
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| 08:24 | this now because there is a little of differences of these pathways but for |
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| 08:29 | you should know that the superior curriculum involved in visual uh information processing, |
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| 08:37 | curricula in the auditory. Said earlier the right. What about the, |
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| 08:53 | uh we've come up to the we to the pineal gland in the |
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| 09:00 | Do you remember when we talked about ? Yeah. Renee Renee the card |
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| 09:08 | he thought it was the touch of mind and body intersection through the pineal |
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| 09:14 | . And he thought that because it's located but it's involved in some other |
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| 09:20 | and some of the hormonal functions and of the uh slower kind of growth |
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| 09:28 | functions and we don't discuss much of structure or how it plays into it |
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| 09:35 | it's definitely not the contact of the the soul of the body. So |
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| 09:42 | good of you to remember Now what are going to study more and try |
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| 09:48 | understand more of the 12 cranial And we're gonna talk about 12 cranial |
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| 09:56 | but we're gonna talk in detail about five of these 12 cranial nerves and |
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| 10:03 | cranial nerves. Remember everything from the down is sub served by the nerves |
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| 10:10 | go through the spinal cord seven. above the spinal cord you have |
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| 10:18 | Oblong gotta pawns midbrain and above that have done this is the brain stem |
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| 10:26 | . Live brain policy of Madura and out of the brain stem. You |
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| 10:32 | these different nerves that handle everything around base and head. So if all |
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| 10:40 | the sensor information touch from the limbs trunk up to the neck comes into |
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| 10:48 | spinal cord and gets processed by dorsal ganglion south. Everything above basically this |
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| 10:58 | is now process the sensory and motor of your facial muscles. So when |
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| 11:05 | output motor command to move my okay that goes from the spinal |
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| 11:14 | When you put out the motor command wink, wink you don't involve the |
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| 11:21 | cord except you're moving. So maybe do. But if you just go |
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| 11:26 | , wink that does involve spinal It now involves all of these cranial |
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| 11:34 | And you have 12 of them. a factory nerve which is not shown |
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| 11:44 | is number one. But olfactory nerve communicate information via the olfactory bulbs. |
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| 11:52 | the olfactory bulbs. The optic nerve number two, The Ocular Motor Nerve |
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| 12:02 | # three. If you look at of the names of the nerves, |
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| 12:10 | tell you what they do. If is a factory nerve, it's all |
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| 12:18 | . Okay if it is optic nerve is obviously visual information. What about |
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| 12:27 | motor Oculus? Is the eye or eye. Ball motor. That means |
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| 12:35 | this nerve has to do something with the motor function of the eyeball? |
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| 12:42 | you have some other names like. clear that don't really explain what they |
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| 12:48 | and we don't really talk much about of them. But I'll tell you |
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| 12:51 | ones I would like for you to because it relates to the material that |
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| 12:55 | already know. The material that we're to study. In the next few |
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| 13:01 | toward the end of the semester as . So forth is stroke with a |
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| 13:07 | , fifth nerve and you can see they're distributed from my brain. The |
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| 13:13 | contains the largest nerve, trigeminal the fifth nerve. Try because it |
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| 13:21 | three components of this facial nerve. , it penetrates into different muscles and |
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| 13:28 | of your face. It's important to trigeminal nerve because it's the largest |
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| 13:34 | So when you look at it either you know the lateral view or from |
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| 13:41 | ventral frontal view, you should be to recognize the trigeminal nerve is the |
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| 13:47 | nerve apart from the two optic nerves havoc i asthma. That's also very |
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| 13:52 | to identify this. I may not you to identify either nerves but those |
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| 14:00 | and as far as labeling you should the optic nerves and the chi asthma |
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| 14:04 | the trigeminal nerve. For sure. , if you can notice that the |
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| 14:11 | are from the superior to inferior in water 123456789 10. 11, |
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| 14:20 | So if I ask you where the 11 or 12 nerve is located, |
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| 14:26 | it likely that it's located in midbrain . You should be able to not |
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| 14:33 | remember what's number 11, nervous or 12 what its function is, but |
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| 14:38 | would it be located along these three parts of the brain stem. So |
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| 14:44 | is also would be a good question the test. Okay, we have |
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| 14:50 | trigeminal nerve number six abdu since number . We don't talk much about educational |
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| 14:56 | nerves. Number seven don't talk about about this nerve either. The |
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| 15:02 | Cochlear nerve is number eight. But another nerve that I want you to |
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| 15:07 | . The stimulus to coke leah the , the stimulus apparatus balance cochlear to |
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| 15:15 | . So this is the nerve that carry information from the cochlear one component |
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| 15:21 | the cochlear the other component from the apparatus. Number nine is gloss. |
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| 15:30 | , for NGO gloss. Oh this , for angel is pharynx. |
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| 15:39 | so like I mentioned in the past , sometimes you have to take these |
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| 15:43 | and break them into 23 pieces and understand where it's located or what it |
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| 15:49 | be related to. It's related to tongue function to the pharynx function. |
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| 15:54 | maybe movement of the tongue. Maybe things like that? Hipaa glass |
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| 16:02 | The glass. So is the town high phone was underneath. So it |
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| 16:07 | something to do with underneath the town . And you have accessory number of |
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| 16:14 | . So we skipped over Chester Nerd the last one was half of loss |
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| 16:19 | number 12. And it's difficult to all of these cranial nerves. And |
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| 16:28 | what I did is I did a diagram for you guys. Let's see |
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| 16:33 | I can get this closed. That a pneumonic of how to remember the |
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| 16:51 | , the 12 nerves and how to the five nerves and I will point |
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| 16:55 | you that we need to know. we came up with this pneumonic when |
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| 16:59 | were studying for our undergraduate exam and was really cool because my undergraduate |
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| 17:06 | the head and neck component of neuroscience labeling these nerves on the actual human |
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| 17:13 | . So we didn't do it with or with even a pencil, but |
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| 17:19 | actually had to go and look at the nerves are, what labels are |
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| 17:25 | and then identify them properly. And we have to know all of these |
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| 17:31 | . My my class had to know of these 12 rooms, all of |
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| 17:36 | functions, all of their locations and and label all of them on the |
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| 17:40 | human cadavers. So we're just gonna a little bit easier. But we |
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| 17:44 | sitting in the evening and we were how are we gonna remember? And |
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| 17:47 | looked at some harmonics that were there then we came up with something silly |
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| 17:51 | now stuck for, you know, some years or something. So Bugs |
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| 17:57 | says, oh to touch and feel green vegetables. Ah So what does |
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| 18:08 | mean in this case? Oh ! first letter to touch. The first |
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| 18:14 | indicates the first letter of the cranial . So Oo factory. Oh optic |
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| 18:20 | ocular motor too. Trow clia touch a abdu since f feel divas to |
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| 18:29 | a cochlear G glass differential. The nerve with skip number 10 vagus nerve |
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| 18:36 | is very important. And I want to know it because you already know |
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| 18:40 | . And then we have the accessory is ah hipaa glass cell which is |
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| 18:48 | . So this is our kind of pneumonic into remembering the order of the |
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| 18:56 | . And giving us a hint of name of the nerve. So for |
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| 19:02 | guys for this class, I want to know the first three or factory |
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| 19:08 | we mentioned it. Look at the bulb, Look at the factory what |
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| 19:11 | does. It's basically smell optic because will discuss it within the context of |
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| 19:17 | visual system. Ocular motor because it what it does and that will give |
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| 19:23 | the clue and some of the names the nerves in the future if you're |
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| 19:28 | to pursue it in any other professional that you can remember, some of |
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| 19:32 | by what the name is is what function is. So 1, |
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| 19:39 | 35 Trigeminal. I want you to trigeminal now. eight. The |
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| 19:47 | Cochlear nerve. The reason why I you to know trigeminal nerve. It's |
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| 19:51 | largest stock of the nerve. It's almost in the middle of the brain |
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| 19:56 | which would place it within palms. . And it's very easy to |
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| 20:03 | And the reason why I want you know this to be Lecoq Leonardo is |
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| 20:08 | we will study the cochlea outputs and we study the auditory system, the |
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| 20:15 | system and finally number 10 vegetables. vagus nerve and vagus nerve is because |
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| 20:26 | already know it as the nerve that used to discover simulation of Vegas to |
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| 20:33 | silk Colin released in the heart. also one of the nerves that runs |
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| 20:38 | most extensively throughout the body and innovates hard innovates. The viscera has very |
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| 20:45 | innovations throughout the body. You Some of these cranial nerves are |
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| 20:53 | some of them are motor, some them are both, which means that |
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| 20:57 | have a sensory component in the fiber and motor component which is the output |
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| 21:04 | goes through the muscles of the face the, of the, of the |
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| 21:09 | of the tongue and so on. we had another pneumonic for bugs |
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| 21:18 | Another one said so so much But my brother says, bugs bunny |
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| 21:26 | more. So what does that That was our pneumonic to remember 12 |
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| 21:33 | . 12 Cranial nerves. S stands censoring. M stands for motor b |
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| 21:40 | for both. So so is So is S. Much as |
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| 21:47 | Money M. But is both. is m brother is both. So |
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| 21:57 | one. Number two A sensory sensory , whole factor and optic nerve carrying |
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| 22:03 | information. Number three is motor. what it is called? Ocular |
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| 22:09 | Number five. Not only is very , it has three components but it's |
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| 22:17 | . It's sensory and motor. So the sensory motor Number eight Mr Klia |
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| 22:28 | sensory and number 10 bunny is Yeah So again for the exam I |
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| 22:40 | you to know 12358 and 10 Half of these 12 cranial nerves. Um |
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| 22:55 | again if you find yourself in some school after this pursuing a higher degree |
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| 23:03 | very likely to come back to these nerves if you're gonna stay in the |
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| 23:08 | of neuroscience of geometry, dentistry. school has neuroscience. Dental neuroscience I |
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| 23:18 | the second semester of the first year a portion of the year and cover |
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| 23:26 | cranial nerves as well. So hopefully pneumonic can help you. You can |
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| 23:34 | your own, you can create your , you can borrow somebody else's. |
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| 23:38 | are many. It's something that worked me. I can't forget it. |
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| 23:44 | not that I like it but it okay. Yeah we need again. |
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| 23:55 | you repeat which ones we need 112358 10 12358 10. Thank |
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| 24:06 | You're welcome. Let's see if I . So what brings you out of |
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| 24:21 | So this is how we can study remember the cranial nerves and like I |
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| 24:28 | we'll come back and for example learn the south that comprise the optic |
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| 24:33 | learn about the south and the accent the south that comprise the cochlear nerve |
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| 24:39 | we'll learn about their pathways and projections these visual auditory systems. Okay spinal |
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| 24:50 | . We briefly discussed final chord. everything again as you can see from |
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| 24:57 | from the skull down information this process the spinal cord and you have cervical |
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| 25:06 | for the thorax, lumber and then portions of the spinal cord. And |
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| 25:14 | have cervical vertebra which is c. through cervical vertebra. C. |
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| 25:23 | So there's seven cervical vertebra. Then have 12 T. One through |
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| 25:30 | 12 of the thoracic vertebra. Then have five L. One through |
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| 25:39 | Five of lumber vertebra in your lower . And then you have the sacred |
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| 25:47 | and the sacred nerve coming out of . Now in between each one of |
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| 25:55 | vertebra, you can see about one. You have the first cranial |
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| 26:01 | . Then you have the eighth cranial nerve that is coming from the 7th |
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| 26:11 | cervical vertebra and first thoracic vertebra. you have the first thoracic nerve. |
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| 26:20 | in between each one of the vertebra have a branch of this nerve that |
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| 26:26 | us on one side and on the side of the body. Okay, |
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| 26:33 | chord proper such as one continuous structure looks like a tube. Okay. |
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| 26:40 | ends at about L. Two, . Three. Number two. Number |
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| 26:48 | . So in about this area this the first lumber vertebra, this is |
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| 26:53 | second in this area. The spinal ends being one continuous like a tube |
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| 27:03 | turns into dispersed fiber bundles. And dispersed fiber bundles referred to as cada |
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| 27:13 | , a queen, A. For , which is a horse cada |
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| 27:21 | It's for tail. So horse's tail the spinal cord now looks like flared |
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| 27:29 | horses stale where each one of the is a spinal uh their bundle |
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| 27:37 | And this is the information at each is a different information. So if |
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| 27:44 | are feeling pain in the shoulder for , it's very likely that pain has |
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| 27:52 | do something with either the upper thoracic the lower cervical vertebra. Um If |
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| 28:03 | pain is not related to direct injury your shoulder, but it is a |
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| 28:07 | that you have a pinched nerve and that level would be affecting your |
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| 28:14 | there was for example uh something that impaired at the vertebrae here, then |
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| 28:22 | nerves that are supplying the thorax will affected and that might be painful around |
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| 28:30 | upper waist and and the rib cage intercostal muscles in the rib cage and |
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| 28:37 | like that. Okay, so now have this understanding of different nerves. |
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| 28:46 | . One through T. 12. you have 12 thoracic nerves. You |
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| 28:50 | eight cervical nerves, 12 thoracic You have five lumber nerves and the |
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| 28:57 | nerve. You remember? These nerves comprised of the sensory and motor components |
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| 29:04 | each side. This one fiber bundle we call the spinal nerve contains the |
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| 29:11 | coming into the dorsal root ganglion. is here through the peripheral axons and |
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| 29:18 | the central axons into the dorsal side the spinal cord. And if you |
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| 29:24 | in the spinal cord you have this are called the dorsal horns and eventual |
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| 29:32 | . But the shape that you're looking looks almost like a butterfly shape so |
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| 29:39 | dorsal root ganglion cell axons, the axons from this bundle here from the |
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| 29:46 | from the selma's will innovate through the side of the spinal cord and mostly |
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| 29:54 | ventral column. I'm sorry the dorsal of the spinal cord and mostly the |
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| 30:02 | horn. Here. The motor neurons the gray matter here of this butterfly |
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| 30:10 | the, so most of these neurons surrounded by the white matter which are |
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| 30:16 | bundles. And these fiber bundles are from lower extremities and descending from information |
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| 30:25 | the higher centers in the C. . S. Eventually in this ventral |
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| 30:31 | you will have selma's of the motor that will send their axons into the |
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| 30:39 | right? And they will join co here the sensory fibers into forming one |
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| 30:46 | spinal nerve that we call spinal So we said that there are eight |
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| 30:52 | spinal nerves so each one of them each side will have the dorsal root |
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| 30:57 | component and the outgoing ventral motor neuron . You can see that the spinal |
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| 31:07 | is also cushioned and surrounded by subarachnoid, arachnoid space and dura modest |
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| 31:16 | protection. You don't have that same of protection where you have caught a |
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| 31:23 | . A of course. Now the thing to notice is that you have |
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| 31:30 | different structures that are labeled here such dorsal column, lateral column and eventual |
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| 31:39 | . And these are white matters. this is white matter. And because |
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| 31:44 | white matters, the fiber bundles that either sending or descending through the spinal |
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| 31:50 | . So the major the major ascending all of the sensor information. Even |
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| 31:58 | it's reflexive, you moved your hand something like this at information from the |
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| 32:06 | from this cervical thoracic region is going inform my head even if it's a |
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| 32:14 | . But most of the time it's the reflex. This command is coming |
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| 32:18 | contra lateral side from the contra lateral cortex. But that information something touches |
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| 32:25 | is gonna go into the spinal cord it's going to ascend up because if |
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| 32:32 | touches me. I may have a behavior to it like a fire or |
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| 32:37 | sharp right? But I'm also going be consciously aware of it and subsequently |
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| 32:44 | other output functions on the output motor . So all of these fibers gonna |
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| 32:50 | carrying, sending information, sending sensory through dorsal column. And the other |
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| 32:58 | faculties are spinal Kalanick faculties here and you have a whole bunch of descending |
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| 33:07 | pathways. So why are this ascending are sensory and descending pathways for |
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| 33:15 | Because ascending is carrying the sensory information censor information, descending is a command |
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| 33:25 | perform among motor function. So the motor pathways and you have cortical spinal |
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| 33:31 | , spinal made jewelry ridiculous spinal tech spinal ponting vertical spinal that's the people's |
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| 33:38 | tract. You have the lateral path venture medial pathways that are descending motor |
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| 33:45 | for the exam. I want you know the dorsal column. Okay, |
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| 33:50 | it's a major ascending bundle, it's the dorsal side, its dorsal column |
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| 33:57 | it's fairly easy to identify on the . But again, pay attention for |
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| 34:06 | that the name of that tract tells where it originates and where it is |
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| 34:15 | . Spinal thalamic is going from the to thalamus. Okay, how about |
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| 34:23 | to spinal. Remember text. Um it goes from tech TEM to |
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| 34:31 | The stimulus final the stimulus Perata's to . Okay, so I don't want |
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| 34:40 | to know the major descending motor pathways I want you to know and understand |
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| 34:48 | they their names a lot of We'll tell the cortical spinal where it |
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| 34:55 | cortical and where it's going spinal or other way spinal thalamic where originates in |
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| 35:02 | spine and where it's going into the . This is autonomic, miserable peripheral |
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| 35:13 | system and all of the organs that their innovations of sympathetic ganglia and the |
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| 35:23 | nervous system. This is showing you innovation of the vagus nerve. The |
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| 35:28 | nerve will have very extensive projections throughout the viscera and into the heart and |
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| 35:34 | organs. Okay. And this pretty ends this last slide because we don't |
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| 35:40 | much about peripheral nervous system that pretty ends our discussion on the C. |
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| 35:46 | . S. And the last remainder the time today. And we have |
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| 35:53 | a bit of time left. I talk a little bit about imaging and |
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| 35:58 | maybe briefly start introducing the visual So we'll see what happens over the |
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| 36:05 | couple of lectures but we may be to catch up with the syllabus as |
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| 36:09 | go. And once we understand the of the brain we start understanding what |
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| 36:17 | parts of the brain responsible their The Holy Grail and the clinical world |
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| 36:22 | to be able to look at the of the brain non invasively. And |
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| 36:28 | is difficult to do that because most the techniques for example that look at |
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| 36:34 | brain function are static techniques. So may have heard of computer tomography or |
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| 36:41 | scans or ct imaging and ct imaging X ray in multiple dimensions. It |
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| 36:50 | penetrates in different focal planes throughout imaging specific part of the body or specific |
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| 36:57 | of the brain or the entire But there's static images and C. |
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| 37:04 | . Can be used. Well if are for example detecting changes in the |
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| 37:09 | the bone mass because X rays are good right? When you break a |
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| 37:14 | you don't go and do FmR. functional magnetic resonance imaging. But typically |
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| 37:19 | do an X ray to an X of your teeth. You see the |
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| 37:23 | really well. So C. Will show you the bones and the |
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| 37:28 | structures really well if there's abnormal growth fluid in contrast. So there are |
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| 37:36 | that can be injected as you undergo procedures like CT and they're injected in |
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| 37:42 | blood vessels. So there's a contrast there's a difference between certain tissues and |
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| 37:47 | blood vessels that you can gain. you can use this to identify large |
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| 37:55 | , abnormal collections of fluids and But it doesn't tell you about the |
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| 38:02 | function. And of course you would C. T. Two. For |
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| 38:07 | if somebody has a brain tumor. . Zorg leo sell originating tumors are |
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| 38:15 | of the most common tumors of the but it will not tell you about |
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| 38:19 | function of neurons around these tumors. also have a magnetic resonance imaging technique |
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| 38:27 | uses measures hydrogen atoms. It has X ray and we'll talk about it |
|
| 38:34 | a little bit more detail an R. I can be functional but |
|
| 38:39 | have to be functional for us. most interesting in neuroscience is the function |
|
| 38:46 | neurons, not just how the brain change statically as a part of |
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| 38:52 | For example. Alzheimer's disease or tumor or rewiring following traumatic brain injury or |
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| 39:03 | like that. But it's really interesting neuroscientists to know the function. How |
|
| 39:09 | we measure the function? And the lecture I believe or maybe second |
|
| 39:13 | I showed you look at these brain when the person is looking at the |
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| 39:19 | there uh occipital lobe is very active the person is listening to the |
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| 39:25 | their temporal lobe is very active. how do you obtain that kind of |
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| 39:31 | that you can non invasively measure activity somebody's skull? And you do that |
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| 39:38 | pet which is positive on emission NFL moronic and mind you that pet |
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| 39:46 | , for example will also be used different settings. For example on diagnosis |
|
| 39:50 | cancers and other parts of the body part of the body. But it |
|
| 39:56 | also be used to measure the These are very sophisticated, expensive experiments |
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| 40:03 | measure brain activity and so can M. R. I. When |
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| 40:07 | measure brain activity and when neurons are neurons. Although the brain is only |
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| 40:15 | 3.5 for some of the total body It consumes over 20% of the total |
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| 40:23 | That we intake through the mouths and mouths produce our own energy. 20% |
|
| 40:33 | into the brain. And when neurons active, they require more oxygen. |
|
| 40:39 | blood flow to the regions of the neurons increases the oxygen consumption increases glucose |
|
| 40:49 | . Okay, also increases so nutrient and oxygen consumption increases in the neurons |
|
| 40:57 | are acting. So if you have active region in the back of the |
|
| 41:01 | , you can start imaging it. one of these two techniques, |
|
| 41:08 | you have a hydrogen atom, one and it can jump high energy or |
|
| 41:15 | energy state. And the frequency at low state protons absorb energy is called |
|
| 41:21 | frequency, which they basically bounce between two states. And you have radio |
|
| 41:28 | that are emitted by protons. So uh and F. M. |
|
| 41:36 | I. You have to go inside coil which is a magnet. It's |
|
| 41:44 | very strong magnetic coil. So you're supposed to wear any anything metal. |
|
| 41:49 | if you walk in from cafeteria and forgot a spoon in your pocket and |
|
| 41:53 | fly and attach itself to the Very powerful magnets. Sometimes you will |
|
| 41:59 | descriptions. It's T. Five magnet stands for Tesla five T. 77 |
|
| 42:07 | magnets are very powerful magnets that to those radio waves that admitted by protons |
|
| 42:14 | can show you active regions of the . So you don't you you don't |
|
| 42:19 | to just see the anatomy and changes anatomy but you also want to see |
|
| 42:24 | active regions in the brain. functional imaging and other kind of functional |
|
| 42:32 | is pet here. You actually get with the radioactively labeled solution with positively |
|
| 42:40 | ions. Okay so it's blood So if you're going to do pet |
|
| 42:49 | you typically get this injection and then have to wait to become radioactive fully |
|
| 42:58 | half an hour to an hour. then the procedure I think is about |
|
| 43:05 | minutes depending on how much of the their imaging the full body or a |
|
| 43:11 | part of the body. The person gets injected with radioactive label material. |
|
| 43:16 | sit in a separate room. So you go with somebody to pet scan |
|
| 43:21 | won't be able to sit with them that hour while they're hot. Uh |
|
| 43:27 | cannot because they are actually radioactivity and a half life of about two I |
|
| 43:35 | 24 hours these radioactively labeled materials to out of your system. Not everybody |
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| 43:41 | handle these procedures. People have claustrophobia if you're going into the M. |
|
| 43:48 | . I. And F. R. E. Coil, especially |
|
| 43:51 | the head imaging or something, it be loud and it could be confining |
|
| 43:56 | space. Um They have to sedate sometimes with general anesthesia including general |
|
| 44:05 | If they want to image certain parts the body. So it's not the |
|
| 44:10 | as dental X ray. This is techniques are a lot more involved. |
|
| 44:15 | you can think of trying to image child's brain using M. R. |
|
| 44:23 | . Or cat scan or even M. R. I. Where |
|
| 44:28 | placing them in this really strange, confining environment. You know. |
|
| 44:35 | not everybody can make through through these of procedures, but I'm just pointing |
|
| 44:41 | out that, you know, this this is not just your regular dental |
|
| 44:45 | ray that you get on a yearly . Yes, I don't think there's |
|
| 44:58 | risk of getting cancers and I think if you're getting them a lot, |
|
| 45:05 | you're exposed to repeatedly it then I'm sure if you have a risk for |
|
| 45:14 | . You may have other problems before have a risk of cancer. And |
|
| 45:18 | would be like liver problems. Because these foreign materials, they get filtered |
|
| 45:26 | they get filtered through the kidneys and get filtered through the liver and they |
|
| 45:31 | metabolized by the liver and it could an overload. And that is that |
|
| 45:37 | an important point that if somebody for has compromised organ function such as liver |
|
| 45:48 | metabolism of some of these injectable materials they may have to think twice or |
|
| 45:55 | not even be able to go through procedures that require the contrast agents and |
|
| 46:00 | require the radioactively labeled agents. Good . So now in positron emission |
|
| 46:09 | you're looking at glucose consumption. We protons that bind electrons. And electromagnetic |
|
| 46:17 | of these coils will pick them up you can see how small the space |
|
| 46:22 | . It's not it's not a big . These coils are big. They |
|
| 46:26 | like big rooms around the magnets, a lot of times the spaces that |
|
| 46:31 | have to enter in this is for head scan, we probably wouldn't even |
|
| 46:35 | able to fit the body and the scans. It might be different variations |
|
| 46:39 | these. Yeah. You know, always do that. You get like |
|
| 46:45 | they really still how still do you have to sit inside the M. |
|
| 46:51 | . I. Like for to get sorted. Yeah, that's it. |
|
| 47:00 | another great question. So You have be very still. It's a great |
|
| 47:08 | . So when they do this image procedures, yeah, you kind of |
|
| 47:10 | like toss from side to side and over so you just 10 minutes into |
|
| 47:16 | . The procedure takes 20 minutes. know, you're like, I can't |
|
| 47:21 | this anymore. You start shaking your start over because a lot of, |
|
| 47:25 | know, for functional, of course doing fast imagery. Some of these |
|
| 47:30 | things that we're talking about, you be doing slow imaging and you're starting |
|
| 47:33 | here, moving down, moving moving down and ending here. You |
|
| 47:39 | from here, you're moving down and doing it in different planes and different |
|
| 47:44 | dimensions. And then you're like stop , you know, because now hypothalamus |
|
| 47:49 | disconnected from the thalamus someplace. So , so you have to be really |
|
| 47:56 | and there's just you just have to your best as a patient. You |
|
| 48:00 | , sometimes you have to be really patient, you have to do these |
|
| 48:03 | , you know, to get some solved or something in answer, you |
|
| 48:09 | ? So if if in uh pet sir, using d glucose consumption to |
|
| 48:17 | oxy glucose is a measure of glucose because active neurons will be consuming |
|
| 48:23 | So wherever you see these hot the red spots, these are the |
|
| 48:30 | of neuronal activity or what we call maps of brain meat, heat maps |
|
| 48:35 | accurate south active networks. And you present certain stimuli to the subjects, |
|
| 48:42 | you can have them listen to music then you turn off the music so |
|
| 48:46 | can image their brain activity as they're to music. And then this is |
|
| 48:51 | stimulation, listening to music. And you turn off the music and you |
|
| 48:55 | the same images of the brain activity controls and the day different. So |
|
| 49:01 | can subtract two images of activity that obtained from stimulated and stimulated brain. |
|
| 49:10 | the difference will tell you what part the brain was involved. This suggests |
|
| 49:16 | maybe it's the I don't even know orientation, but I think this is |
|
| 49:24 | no, this is the frontal, think this is a tough problem. |
|
| 49:27 | would be the surveillance is some something do with with the frontal lobe |
|
| 49:32 | You you're measuring the levels of him Logan oxy hemoglobin versus de oxy |
|
| 49:44 | If the South have more oxy if the oxy hemoglobin ratio is greater |
|
| 49:49 | the oxy it means the South are using as much uh oxygen. So |
|
| 49:58 | will carry oxygen and if the neurons very active they will deoxygenated which is |
|
| 50:06 | hemoglobin or d oxy hemoglobin. And the cells that are more active will |
|
| 50:12 | greater amounts of deoxygenated hemoglobin and the supply to the areas of neuronal networks |
|
| 50:20 | are engaged in different activities as they're to the subject. So these techniques |
|
| 50:27 | immigrant functional activity or not real there's some delay between when there is |
|
| 50:33 | stimulation or a task and how fast techniques can pick up the information. |
|
| 50:40 | obviously are not seeing individual structures You're not seeing the boundaries like in |
|
| 50:46 | side architect tonic maps. You have overlap these images usually with steri attacked |
|
| 50:53 | or information about the brain, you to know the maps and all of |
|
| 50:58 | focal plane. So as a radiologist brain scans, you should be able |
|
| 51:03 | identify different structures quite easily or the based on the stereotype toxic or the |
|
| 51:11 | that are given to you to identify locations in the brain. You can't |
|
| 51:16 | individual neurons. There is no microscopic here. It's only macroscopic resolution, |
|
| 51:28 | highest facial resolution that these techniques can . Or maybe on the order of |
|
| 51:36 | . And neurons are 10 μm in . Some of these imaging and advanced |
|
| 51:44 | techniques functional and moving down to uh millimeters instead of a centimeter which is |
|
| 51:54 | millimeters to two millimeters or one millimeter is in the town Which is a |
|
| 52:01 | microns. So you're still looking at and these responses a single pixel or |
|
| 52:09 | imaging referred to as Vauxhall. A pixel from this image would represent hundreds |
|
| 52:16 | not thousands of active cells or inactive as it may be. Okay. |
|
| 52:24 | I think ultimate goal is to have much higher resolution, a lot less |
|
| 52:35 | radioactive materials or anything that can overload organ function. When you're doing these |
|
| 52:42 | techniques like in pet scan, uh materials and N. C. |
|
| 52:49 | Scans and the ability to do it fast. So if we could get |
|
| 52:56 | to a few cell size networks non through these coils really fast speed, |
|
| 53:07 | know, if not at one millisecond is one kilohertz but close to |
|
| 53:13 | that would be great because then if get to about one kilohertz or one |
|
| 53:18 | speeds, you can start picking up potential activity. So right now it's |
|
| 53:25 | really action potential activity. It's it's a collection of both. Pre synaptic |
|
| 53:31 | post synaptic and most likely represented. synaptic activity of the of the |
|
| 53:38 | So for the F. M. . I. It doesn't require any |
|
| 53:43 | material. Just measuring oxygen consumption. . You murdering the human. Global |
|
| 53:51 | . The oxygenated oxygenated. Okay, good. We're done with C. |
|
| 54:04 | . S. Can you believe So we started from single South, |
|
| 54:09 | moved into the action potentials, neurotransmitter , releasing communication between South. We |
|
| 54:21 | at what's going on and uh in brain as a whole and how the |
|
| 54:35 | developed. And now we're gonna start into systems. So the visual system |
|
| 54:40 | a system because it isn't one there's just not one thing, it's |
|
| 54:44 | just an eye. The retina, eyeball structure. The retina communicates in |
|
| 54:50 | most ominous, communicates to the primary cortex, primary to the secondary, |
|
| 54:55 | , tertiary ordinary independent association areas. that's a whole system for us to |
|
| 55:03 | what we call a gestalt, the of form or the control, the |
|
| 55:11 | configuration and form of the visual view you're seeing here and the different aspects |
|
| 55:16 | that view. Color movement, depth to depth. So that when you |
|
| 55:24 | at the people sitting fire in the of the classroom, I don't think |
|
| 55:28 | they're half the size of the people in the front of the classroom, |
|
| 55:33 | different cells that react to bright lights dark lights that's all a part of |
|
| 55:39 | digital system neurotransmitters of themselves release the how they process that information. So |
|
| 55:46 | the next 2.5 lectures we will attempt walk through the visual system and if |
|
| 55:55 | follow through from the circuit and the all the way to the primary visual |
|
| 56:02 | and organization along the way of these system projections. Then at the end |
|
| 56:09 | the third lecture, you understand how form the primal sketch of the outside |
|
| 56:17 | and some of the aspects of the such as color in motion and directionality |
|
| 56:24 | processing of the south individual cortex. we see represents properties of objects and |
|
| 56:30 | organization of sensations by the brain. a certain structure in our cortex. |
|
| 56:36 | were born with a code with a assembly it assembled that pretty much similar |
|
| 56:42 | your parents. Maybe a million years that will be assembled a little |
|
| 56:47 | but that is a slow evolving Um so we're limited to what we |
|
| 56:57 | by the structure and function of our system and different components. Oh, |
|
| 57:05 | the way guys, the average on was 7.7. Good job. So |
|
| 57:11 | average for the exam was 76. forgot to mention it. The low |
|
| 57:17 | on the quiz was to the high were several tens. Uh So it |
|
| 57:24 | to take the quiz and 7.7 is yourself 3/4 of a grade up actually |
|
| 57:34 | it to your exam scores come. , I forgot to mention that I |
|
| 57:38 | it down but I never talked about . Okay, let's go back to |
|
| 57:42 | visual system. So we have these dimensional experiences and we form a lot |
|
| 57:49 | these three dimensional experiences. Of course see things in three dimensions, but |
|
| 57:53 | far away things are still in two . You know, This is the |
|
| 57:59 | on the board. The line on board is two Dimensions. Another line |
|
| 58:06 | another two dimensions. All right, is all two dimensions. And if |
|
| 58:19 | were to ask you, what is , you will say the box and |
|
| 58:29 | looks like a box and it looks it has the front, it has |
|
| 58:33 | top has the side and you imagine probably has the back. There's another |
|
| 58:38 | you cannot see. But it's just dimensions of lines and dots on the |
|
| 58:47 | . So we form these three And a lot of the assumptions we |
|
| 58:51 | about three dimensions is because of the knowledge from the sensory stimulations and because |
|
| 58:57 | the background structure of the brain and circuits of processes information. And we |
|
| 59:05 | them into more or less stable So that is constant despite the information |
|
| 59:13 | in in and in what we think is despite the changes and information. |
|
| 59:20 | changes this information as if I were walk away far from this chair. |
|
| 59:25 | still think I can sit on this and shrink that if I walked around |
|
| 59:29 | chair, we still think it has legs. Although I can't can only |
|
| 59:33 | three now. But I'm not thinking just hanging on three legs, you |
|
| 59:39 | ? Well you can't see all the . If I turn start right, |
|
| 59:44 | you can't even see them holding it my m you know, so but |
|
| 59:48 | still it's still the same chair. we see it the same way we |
|
| 59:54 | certain assumptions about what is to be in the world. Their expectations. |
|
| 59:59 | , that we derived from the sensor and from the built in wiring. |
|
| 60:07 | make certain assumptions. So if you on top uh an ambiguous pattern in |
|
| 60:14 | if I were to ask you, do you see here, the most |
|
| 60:17 | answer would be I see columns of and yellow dots and what do you |
|
| 60:24 | here? I see rows of yellow blue dots and that's what we call |
|
| 60:32 | principle of similarity. We tend to similar things together in in color or |
|
| 60:38 | pattern or in shape and in this we grouped together blues into a line |
|
| 60:46 | yellows into a line when in fact not what the artist intended. The |
|
| 60:51 | intended. Yellow, blue, blue, yellow, blue. It's |
|
| 60:55 | alternating column of yellow and blue. hard to make your brain think about |
|
| 61:03 | that these are columns. His lines actually article lines rather than the |
|
| 61:10 | similar looking objects in the horizontal proximity is another principle. Things that |
|
| 61:18 | close together. So here this blue were moved closer together in the horizontal |
|
| 61:34 | . And now again we think that is columns and we think that these |
|
| 61:40 | rose. But why not? That are columns? Well, it can |
|
| 61:48 | right, but just it's difficult to about it because we group them together |
|
| 61:53 | wines and here's Arizona lines, here's lines. So we assume certain |
|
| 62:01 | We learned certain things to observe We have a lot of illusions. |
|
| 62:07 | two lines actually have these blue arrow here to show that it's the same |
|
| 62:15 | arrow. But if I didn't have two together, I could even draw |
|
| 62:20 | on the board and they would look lengths. You still arrows pretty pretty |
|
| 62:32 | . I'm gonna take this. I'm go from here to hear. We'll |
|
| 62:41 | the same here from here to hear does the same 1? This is |
|
| 62:52 | same one and this looks so much . Now, The bottom one and |
|
| 63:10 | tough one but they're the same So it's the surrounding the assumptions and |
|
| 63:19 | things, not just the actual object influence of how we perceive it and |
|
| 63:26 | we misread certain things. So somebody you which is a longer line, |
|
| 63:31 | know, most of you say bottom that's a misreading it's actually the same |
|
| 63:35 | . And if I were to do when you realize, oh it is |
|
| 63:51 | the same line because it's a So uh here's kind of a that's |
|
| 64:01 | I was talking about. The person sitting. There's two people sitting. |
|
| 64:04 | is sitting further down the hall where don't assume that that person is half |
|
| 64:08 | size of the person that is sitting to, that could be smaller, |
|
| 64:12 | could be larger. But typically you assume that it looks like it's the |
|
| 64:16 | chair. So you assume it's the size chair, similar sized person. |
|
| 64:22 | you don't think that that person is , really small person sitting down |
|
| 64:26 | And that's the perspective also in the there's a lot more illusions and also |
|
| 64:34 | in nature and patterns. Once we certain patterns and certain delusion, we |
|
| 64:41 | it very quickly. And from that on we can recall it very |
|
| 64:45 | This one is very standard. So either two faces of the base. |
|
| 64:51 | one is yellow is the fish, is the frog. And it's pretty |
|
| 64:58 | . These are very simple optical but quite often people will be just |
|
| 65:04 | on the fish or just on the . And once they see the fish |
|
| 65:07 | the frog will never forget this fish frog there. But you can have |
|
| 65:11 | , very complex optical illusions and you also learn pretty fast. And once |
|
| 65:15 | do, you see it now, can recognize them. Life comes into |
|
| 65:21 | retina. And it carries certain Says electromagnetic radiation. Its ways of |
|
| 65:28 | radiation that have wavelength amplitude and The visible spectrum of life falls in |
|
| 65:36 | wavelength between 400 nanometers to 700 This is what is the visual optical |
|
| 65:45 | that our retinas can perceive by. animals live in different spectrum and they |
|
| 65:52 | perceive the world as heat maps. the bees will be flying around, |
|
| 65:58 | will not be seeing information the same . They will be like more like |
|
| 66:02 | heat maps. But we perceive this . So to the lower wavelength you |
|
| 66:12 | this uh Roy G. Bev orange, yellow, green, blue |
|
| 66:20 | , violet Roy G. Um Red violent on this side of violence. |
|
| 66:30 | have ultraviolet rays, you have gamma x rays and you have gamma rays |
|
| 66:38 | this higher wavelength. You have infrared , radar broadcast bands, a. |
|
| 66:49 | circuit. But the information we can and these are not the only |
|
| 66:57 | There's many, many hues and many hues combinations that we can see within |
|
| 67:03 | different wavelengths of light when the light a different surface. It can do |
|
| 67:15 | of the two things. It can reflected from that surface. So you |
|
| 67:20 | highly reflective materials like a foil for will reflect the materials you can have |
|
| 67:27 | light absorbed. They have absorptive materials darker materials that can absorb the electromagnetic |
|
| 67:36 | . And it lets say the material a different from air to fluid. |
|
| 67:45 | example a different phase. You can rare fraction or bending of the light |
|
| 67:54 | that are coming in. And so what happens when light. It hits |
|
| 68:01 | retina and hits the eyeball and the . This environment inside the eyeball, |
|
| 68:08 | actually retracts and then some of the of light. The information will come |
|
| 68:17 | through the pupil which is surrounded by iris. Have the square here. |
|
| 68:24 | conjure, Activia have the cornea, have the extra ocular muscles. These |
|
| 68:31 | gonna be the muscles that are gonna the eyeball and you have the optic |
|
| 68:37 | that comes out in the back of eyeball in general. What you will |
|
| 68:43 | about is that disinformation the digital information into the retina. We will study |
|
| 68:51 | circuit here in the retina projections from retina going to the lateral nucleus of |
|
| 68:58 | thalamus LG. Which is a six structure from lateral nucleus nucleus. The |
|
| 69:05 | projections go into the primary visual cortical and there are two main processing streams |
|
| 69:14 | break off and diverge from the occipital . The stream that goes into the |
|
| 69:23 | inferior temporal regions and the inferior temporal here is concerned with processing color that's |
|
| 69:34 | key right there. Color, depth . So color depth and form. |
|
| 69:45 | this is also related to the temporal . So it will get intermingled with |
|
| 69:52 | auditory signals in the temporal cortex. other pathway the dorsal parietal pathway projects |
|
| 70:02 | processing the visual information into this dorsal parietal cortex and the pathway that projects |
|
| 70:12 | is mostly interested in motion and depth that's important because if you're looking at |
|
| 70:22 | that's going to be motion, the cortex is over here. You're gonna |
|
| 70:27 | to somehow co join the information that seeing with a motor out with you're |
|
| 70:34 | so when you're moving your hand you're scratching somebody's space that you're stopping your |
|
| 70:39 | the proper way. So there's going be communication through the association areas of |
|
| 70:46 | complex behaviors which involve visual processing, output, verbal output and so |
|
| 70:53 | This is the visual system. So will walk through these different parts of |
|
| 70:57 | visual system. Today we will focus on the eyeball, some of the |
|
| 71:03 | slides. Great labeling slides in the uh eyeball, you have Aquarius humor |
|
| 71:13 | . Okay. Aquarius humor that's provides to this region. So this is |
|
| 71:20 | chris environments and once the light strikes refracts and then this is the second |
|
| 71:27 | environment which is the vitreous humor which the eyeball its shape is gel like |
|
| 71:36 | substance basically there can be uh dysfunctions Aquarius humor and nutrient supply that are |
|
| 71:46 | to a coma. So there are conditions of course that you can have |
|
| 71:53 | you have damage to the nutrients. also conditions that you can have the |
|
| 71:59 | to other systems and inflammation and intraocular and other problems that can happen. |
|
| 72:07 | in general it's a fluid is like the information will commit through the |
|
| 72:13 | You can see that the iris is here by the silvery bodies and the |
|
| 72:19 | serie ligaments. So if these ligaments they relax, this lens is gonna |
|
| 72:29 | thicker. If this ligaments contract, contract we're gonna stretch and we're gonna |
|
| 72:36 | the lens thinner and that's how we focus in and out further distances in |
|
| 72:43 | distances by changing the shape and the off the lens. The retina is |
|
| 72:50 | all the way in the back of eyeball. The optic nerve where it |
|
| 72:56 | out. This is the blind spot here where the optic nerve exits out |
|
| 73:03 | this is what is called the We'll look at it. This is |
|
| 73:07 | most of the direct axial rays of will be directly toward the phobia. |
|
| 73:14 | phobia. I'm gonna go over time and phobia will contain the highest concentrations |
|
| 73:22 | the cone photo receptors. And so is the fiber bundle. This fiber |
|
| 73:28 | is cranial nerve two or optic nerve exits out of the back of the |
|
| 73:33 | . So you can see that the is designed the strongest light to go |
|
| 73:38 | into the phobia. And also you see there's blood vessels are also gonna |
|
| 73:43 | exiting out through the area where you the exit of the second cranial |
|
| 73:49 | Okay we're almost out of time. think we're out of time. So |
|
| 73:54 | gonna take a pause today. We'll a few more slides on the eyeball |
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| 73:59 | then we will move into the structure function of the retina. Retinal |
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| 74:05 | Talk about rods and cones and how get different colors in the eye. |
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| 74:11 | , So have a good weekend the of the week, and I will |
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| 74:15 | everyone here on monday, happy Wednesday |
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