Central Nervous System ppt
description
Transcript of Central Nervous System ppt
![Page 1: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/1.jpg)
CNS
![Page 2: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/2.jpg)
Highlight of Learning ObjectivesLearning Goals Learning Outcomes
Understand the importance of cerebrospinal fluid (CSF)
Diagram the secretion and reabsorption of CSF List the composition of CSF and compare it to the composition of plasmaExplain the significance of having a well-controlled CSF
Understand the blood-brain barrier (BBB) and its physiological significance
Diagram the blood supply to the brainDiagram the BBB and explain how it is formedExplain how BBB controls the movement of substances and its physiological significance
![Page 3: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/3.jpg)
Part I Outline
• Protection and support of the brain– The importance and composition of cerebrospinal
fluid– The importance of blood brain barrier
• Major anatomical divisions of the brain and the primary functions of each part
3
![Page 4: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/4.jpg)
Protection of the Brain
• 1) the bones of the cranium• 2) the cranial meninges• 3) cerebrospinal fluid Figure 15-5 M
![Page 5: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/5.jpg)
Dura mater Arachnoid ArachnoidPia mater
Cranial Meninges
![Page 6: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/6.jpg)
Brain Ventricles
Figure 15-6 M
![Page 7: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/7.jpg)
Cerebral Spinal Fluid (CSF)
• Surrounds brain & spinal cord
• Cushion and protection
Figure 15-8 M
![Page 8: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/8.jpg)
Circulation of CSF• CSF is produce by choroid
plexus in the ventricles
• CSF leave the 4th ventricle via paired lateral apertures or the single median aperture
• CSF flows through the subarachnoid space
• Excess CSF flow into the arachnoid villi, then drains into the dural venous sinuses
![Page 9: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/9.jpg)
As CSF circulates, CSF and the interstitial fluid of the CNS have been shown to have similar ion concentrations, what kind of movement is involved?
A. osmosisB. perfusionC. diffusionD. active transporterE. conduction
Clicker Question
![Page 10: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/10.jpg)
Vascularization
Blood supply•Internal carotid arteries•Vertebral arteries
Blood drainage•Internal jugular veins
![Page 11: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/11.jpg)
Internal Carotid A. Vertebral A.
Basilar a
Posterior Cerebral A.
Anterior Cerebral A.
Middle Cerebral A.
The major arterial supply to the brain
![Page 12: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/12.jpg)
Circle of Williscollateral circulation
![Page 13: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/13.jpg)
Posterior cerebral art.
Middle cerebral art.Anterior cerebral art.
![Page 14: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/14.jpg)
What is the composition of brain interstitial fluid?
(A)Similar to plasma(B) Different from plasma
Clicker Question
![Page 15: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/15.jpg)
Blood-Brain Barrier• Role in water and electrolyte
homeostasis• Endothelial cells of brain microvessels– Ensheathed by astrocyte foot processes– Exhibit complex tight junctions– Very limited paracellular solute flux– Regulate composition and volume of
brain interstitial fluid
![Page 16: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/16.jpg)
BBB and Neurovascular unit (NVU)
Abbott NJ et al. (2006) Nat. Rev. Nuero. 7-41-53
![Page 17: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/17.jpg)
BBB ion transporters and channels
• Regulate the brain interstitial fluid volume and composition in healthy, normoxic brain
• Secretion of NaCl and water into the brain– BBB produces up to 30% of brain interstitial fluid
• Absorption of K from brain into blood– BBB maintains low interstitial [K]
![Page 18: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/18.jpg)
Blood-brain barrier regulation of brain interstitial fluid volume and composition
Altered during ischemic stroke
Leads to cerebral edema formation
Edema is a major contributing factor to morbidity and mortality of stroke
![Page 19: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/19.jpg)
Stroke (brain attack)
Two major causes:• Ischemic stroke– Global• E.g. during cardiac arrest
– Focal• E.g., during occlusion of a
cerebral blood vessel
• Hemorrhagic stroke– E.g., following rupture of a
cerebral blood vessel
1. A blood clot2. Endothelial cell 3. Neuron4. Free radicals
![Page 20: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/20.jpg)
Stroke (brain attack)• Early events
• Late events
![Page 21: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/21.jpg)
Concept map
• Blood-brain barrier• CSF• Blood• Interstitial fluid• Ion concentration in the brain• Brain edema• stroke
![Page 22: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/22.jpg)
Part I Outline
• Protection and support of the brain– The importance and composition of cerebrospinal
fluid– The importance of blood brain barrier
• Major anatomical divisions of the brain and the primary functions of each part
22
![Page 23: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/23.jpg)
Superior View Anterior View
Posterior View
Lateral View
Ventral View
Brain Devisions
![Page 24: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/24.jpg)
Sagittal Plane
Coronal Plane
Cerebral Cortex - The outermost layer of gray matter making up the superficial aspect of the cerebrum.
![Page 25: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/25.jpg)
Cerebral Cortical (Neocortex)
• Neocortex - pyramidal (75%) and granule cell– Layer 1 - axons & synapses, few cell bodies– Layer 2 - granule cell– Layer 3 – pyramidal cell– Layer 4 – granule cell– Layer 5 – large pyramidal cell– Layer 6 – pyramidal and other cells 25
![Page 26: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/26.jpg)
Cerebral Features:• Gyri – Elevated ridges “winding” around the brain.
• Sulci – Small grooves dividing the gyri– Central Sulcus – Divides the Frontal Lobe from the Parietal
lobe
• Fissures – Deep grooves, generally dividing large regions/lobes of the brain – Longitudinal Fissure – Divides the two Cerebral
Hemispheres– Transverse Fissure – Separates the Cerebrum from the
Cerebellum– Sylvian/Lateral Fissure – Divides the Temporal Lobe from
the Frontal and Parietal Lobes
![Page 27: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/27.jpg)
Gyri (ridge)
Fissure
(deep groove)
Sulci (groove)
http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
![Page 28: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/28.jpg)
Major Regions of Human Brain
• Cerebrum– Higher brain functions
• Diencephalon– Centers for homeostasis
• Brainstem– autonomic centers and
reflex centers • Cerebellum– Involve in coordination of
movement
![Page 29: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/29.jpg)
Lateral View
Brain Divisions
![Page 30: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/30.jpg)
Cerebrum
• Frontal– Motor, speech, memory
formation, personality, emotion
• Parietal– Somatosensory cortex
• Occipital– Visual processing and
storing visual memories• Temporal
– Hearing, speech and language, smell
Figure 15-1 M* Note: Occasionally, the Insula is considered the fifth lobe. It is located deep to the Temporal Lobe.
![Page 31: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/31.jpg)
Frontal Cortex
• Traditionally considered to be the seat of intelligence
• Working memory problem• Difficulty generating new
items or hypothesies• Lack of Inhibition• Perseveration• Difficulty planning
sequences or organizing strategies
![Page 32: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/32.jpg)
Primary Motor Cortex/ Precentral Gyrus
Broca’s Area
Orbitofrontal Cortex
Olfactory Bulb
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
![Page 33: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/33.jpg)
Parietal Lobe• It plays a major role in the
following functions/actions:– Senses and integrates
sensation(s)– Spatial awareness and
perception(Proprioception - Awareness of body/ body parts in space and in relation to each other)
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
![Page 34: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/34.jpg)
Primary Somatosensory Cortex/ Postcentral Gyrus
Primary Gustatory Cortex
Somatosensory Association Cortex
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
![Page 35: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/35.jpg)
Temporal Lobe
• They play an integral role in the following functions:• Hearing• Organization/
comprehension of language
• Information retrieval• (Memory and memory
formation)
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
![Page 36: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/36.jpg)
Korbinian Broadmann - Learn about the man who divided the Cerebral Cortex into 52 distinct regions: http://en.wikipedia.org/wiki/Korbinian_Brodmann
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Primary Auditory Cortex
Wernike’s Area
Primary Olfactory Cortex (Deep)Conducted from Olfactory Bulb
![Page 37: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/37.jpg)
Occipital Lobe – Cortical Regions
• Its primary function is the processing, integration, interpretation, etc. of VISION and visual stimuli.– Primary Visual Cortex –the
primary area of the brain responsible for sight -
– Visual Association Area – Interprets information acquired through the primary visual cortex. recognition of size, color, light, motion, dimensions, etc.
![Page 38: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/38.jpg)
Korbinian Broadmann - Learn about the man who divided the Cerebral Cortex into 52 distinct regions: http://en.wikipedia.org/wiki/Korbinian_Brodmann
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Primary Visual Cortex
Visual Association Area
![Page 39: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/39.jpg)
Korbinian Broadmann - Learn about the man who divided the Cerebral Cortex into 52 distinct regions: http://en.wikipedia.org/wiki/Korbinian_Brodmann
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
![Page 40: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/40.jpg)
Primary Language Areas
• Broca’s area• Wenicke’s area• Angular gyrus• Arcuate fasciculus
![Page 41: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/41.jpg)
Language and the Aphasias
Other language dysfunctions
DyslexiaWord deafnessAnomiaConduction aphasia
The Brain from Top to Bottom: From Thought to Language. Broca’s Area, Wernicke’s Area, and Other Language-Processing Areas in the Brainhttp://thebrain.mcgill.ca/fl ash/i/i_10/i_10_cr/i_10_cr_lan/i_10_cr_lan.html
![Page 42: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/42.jpg)
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Conduction Aphasia• Arcuate Fasciculus - A white matter tract that connects Broca’s Area and
Wernicke’s Area through the Temporal, Parietal and Frontal Lobes. Allows for coordinated, comprehensible speech.
![Page 43: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/43.jpg)
Q: Assuming this comical situation was factually accurate, what Cortical Region of the brain would these doctors be stimulating?
Copyright: Gary Larson
![Page 44: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/44.jpg)
Primary Motor and Somatosensory Cortex
* This graphic representation of the regions of the Primary Motor Cortex and Primary Sensory Cortex is one example of a HOMUNCULUS:
![Page 45: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/45.jpg)
Q: What do you notice about the proportions depicted in the aforementioned homunculus?
Q: What is meant by depicting these body parts in such outrageous proportions?
* Note: Homunculus literally means “little person,” and may refer to one whose body shape is governed by the cortical area devoted to that body region.
![Page 46: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/46.jpg)
Phineas Gage was a railroad worker in the 19th century living in Cavendish, Vermont. One of his jobs was to set off explosive charges in large rock in order to break them into smaller pieces. On one of these instances, the detonation occurred prior to his expectations, resulting in a 42 inch long, 1.2 inch wide, metal rod to be blown right up through his skull and out the top. The rod entered his skull below his left cheek bone and exited after passing through the anterior frontal lobe of his brain.
A Case Study
![Page 47: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/47.jpg)
Remarkably, Gage never lost consciousness, or quickly regained it (there is still some debate), suffered little to no pain, and was awake and alert when he reached a doctor approximately 45 minutes later. He had a normal pulse and normal vision, and following a short period of rest, returned to work several days later. However, he was not unaffected by this accident.
Learn more about Phineas Gage: http://en.wikipedia.org/wiki/Phineas_Gage
http://www.sruweb.com/~walsh/gage5.jpg
![Page 48: Central Nervous System ppt](https://reader034.fdocuments.in/reader034/viewer/2022051314/552ee75b4a7959485c8b4aae/html5/thumbnails/48.jpg)
Q: Recalling what you have just learned regarding the frontal lobe, what possible problems or abnormalities may Gage have presented with subsequent to this type of injury (remember the precise location of the rod through his brain)?
Q: It is suggested that Gage’s injury inspired the development of what at one time was a widely used medical procedure. What might this procedure be, and how does it relate to Gage’s injury?