structure of the nervous system @ macroscopic level –brain & nerves @ microscopic level...
TRANSCRIPT
![Page 1: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/1.jpg)
Structure of the nervous system
• @ Macroscopic level– Brain & nerves
• @ Microscopic level– Neurons & Glial Cells
![Page 2: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/2.jpg)
Central (inside skull & spine)
BrainSpinal Cord
Macroscopic: Divisions of the Nervous System
Peripheral (outside skull & spine)
Nerves
![Page 3: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/3.jpg)
Central Nervous System
Brain
![Page 4: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/4.jpg)
Divisions of the human brain
![Page 5: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/5.jpg)
Specialization of function
Different regions of the brain are associated with different function
![Page 6: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/6.jpg)
Spinal Cord Reflex
Spinal cord lesion
Ouch! That hurts, dude!
Group activity
- Would sensation be abolished by:- a spinal cord lesion?- polio?
- Would the reflex be abolished by: - a spinal cord lesion? - polio?
![Page 7: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/7.jpg)
Somatic System:
- controls voluntary muscle
Autonomic System:
- controls glands & internal organs- has two subcomponents
- Sympathetic (adrenaline): arousal- Parasympathetic: calm
Peripheral Nervous System
![Page 8: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/8.jpg)
Figure 3.28 The Autonomic Nervous System
![Page 9: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/9.jpg)
Levels of Investigation Brain Areas
(visual system)
Cells (neurons)
Molecules (neurotransmitters)
![Page 10: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/10.jpg)
Microscopic level: Neurons
![Page 11: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/11.jpg)
11
Neurons: Its many shapes & sizes
![Page 12: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/12.jpg)
Neuron: basic parts
Cell Body football field
Dendrite Campus
Axon wide a street
Axon long as Philly - Ohio
Cell membrane thick as pinky finger
Synaptic cleft thick as thumb
# synapses 10.000 (same number as Villanova students)
Some axons are wrapped burrito-style by fatty cells (glial cells) - increases speed at which neurons communicate)- white in color (white matter vs gray matter- is destroyed by multiple sclerosis
axon terminals
![Page 13: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/13.jpg)
13
Neuron: its physiology
What makes neurons different from other cells?
Neuron’s cell membrane is electrically charged (interior is more negative)
Neurons influence each other’s charge (‘communicate’)
Neurons process and transmit electrical impulses
![Page 14: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/14.jpg)
14
How do neurons process and transmit electrical impulses?
A. dendrites receive input from other neurons
B. axon sends neural impulse to axon terminal
C. a neurotransmitter (NT) is release and makes contact with another neuron (synapse)
![Page 15: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/15.jpg)
Communication Steps
• NT is released from pre-synaptic neuron
• NT binds to receptors in post-synaptic neuron
• Opens Na+ channels
• Sodium rushes in (activation)
• If enough Na+ rushes in => depolarization (action potential)
• NT released by post-synaptic neuronPost-synaptic neuron
Synapse
Pre-synaptic neuron
![Page 16: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/16.jpg)
Other important facts
Various Neurotransmitters (NT):- Dopamine
- Adrenaline
- Serotonin
- Acetylcholine
For each NT,various receptors
- nicotine & muscarine
Drugs can act by
- modifying amount of NT, or
- binding to receptor (nicotine)
The net effect on neuron could be:
- activation (action potential)
- inhibition
![Page 17: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/17.jpg)
Cells of the Nervous System
Glia (Greek=glue)
– Many types (oligodendrocites, schwann cells, astrocytes, and microglia)
– More prevalent than neurons (10:1)
![Page 18: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/18.jpg)
Complexity of CNS
• 1011 (100 billion) neurons • each neuron interacts with 1,000 -7000 others• => 100 -500 trillion connections (that’s a big #)
• Many other factors:– Neurotransmitters– Receptors – Genes, Glial cells etc.
![Page 19: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/19.jpg)
Glial Cells
• Functions: support, immunology (defense), nutrition for neurons, guide migration of neurons during development, maintain ion balance, etc.
• Form myelin which helps the speed of the action potential. In Multiple Sclerosis, the myelin is broken down and axons become less efficient.
![Page 20: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/20.jpg)
Copyright © Allyn & Bacon 2004
![Page 21: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/21.jpg)
Copyright © Allyn & Bacon 2004
![Page 22: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/22.jpg)
Blood-brain barrier
Basal ganglia lesion (hiperdensities) due to increased bilirubin in newborn (kernicterus)
Movement disorder
![Page 23: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/23.jpg)
Spared images
![Page 24: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/24.jpg)
Figure 3.3 The Nervous System
![Page 25: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/25.jpg)
Figure 3.24 Spinal Column, Ventral View
![Page 26: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/26.jpg)
Vertebra of Spinal column
![Page 27: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/27.jpg)
Figure 3.26: Spinal Cord Cross Section
![Page 28: Structure of the nervous system @ Macroscopic level –Brain & nerves @ Microscopic level –Neurons & Glial Cells](https://reader036.vdocument.in/reader036/viewer/2022081603/56649e0b5503460f94af3a18/html5/thumbnails/28.jpg)
Figure 3.25 The Spinal Cord