Nerve Cells

Question 1

Central Sulcus separates:

Answer 1

Precentral gyrus AKA Frontal Lobe (memory, higher thinking, motor control)
-from Postcentral AKA Parietal Lobe (sensory cortex)

Question 2

Lateral Fissure defines

Answer 2

Lateral Lobe (auditory) and in the back, Occipital

Question 3

Brain Stem Compositions:

Answer 3

Diencephalon (relay of sensory to thalums)
Midbrain
Pons (relay between celebellum and cerebral cortex)
Medulla (breathing and heart rate)

Question 4

Substantia nigra

Answer 4

nucleus in Midbrain that degenerates in Parkinsons Disease

Question 5

6 layers of Gray Matter

Answer 5

I. Molecular Layer

• neurophils
  2. External Granular
  3. External Pyramidal
• pyramidal neurons giving corticocortical connections
  4. Internal Granular Layer
• IMPORTANT, receives sensory info from Thalmus via stellate neurons
  5. Ganglionic Layer
  6. Multiform (polymorphic) cell layer
• pyramidal neurons whose axons leave the cortex

Question 6

Cerebellum Layers

Answer 6

1. Molecular
2. Purkinje
3. Granule

Question 7

Purkinje Layer is Important because:

Answer 7

only output cells. receive info from brain stem, accumulates it, and sends it to the deep nuclear cellular layer

Question 8

Nissl substance is in high concentration in what kind of neurons?

Answer 8

Motor Cell

-large amount of nissl substance = large cell size when compared to glia

Question 9

Motor neuron pathway

Answer 9

1. Cortico spinal signal (signal from upper spinal cord to lower spinal cord) travels via white matter axons
2. Signal sent out from VENTRAL root of spinal cord
3. Motor neuron axon transduces signal from CNS to PNS
4. From PNS to muscle fibers

Question 10

4 Categories of Peripheral Nerves:

Answer 10

8 Cervical (3, 4, 5 important for breathing) , 12 Thoracic, 5 Lumbar (4,5 = Sciatic), 5 Sacral

Question 11

ALS Amyotrophic Lateral Sclerosis

Answer 11

Upper Motor Neurons cannot communicate with Lower Motor Neurons = paralysis

Question 12

4 Parts of the Neuron

Answer 12

Dendrite
-Receive information (input)
Cell body
-Sort information (integratge)
Axon
-propagates electrical info transfer (conduct)
Synapse
-sends signal to the next cell (electrically or chemically) (output)

Question 13

Ependyma Cells

Answer 13

(in CNS -> specifically the central canal) Protect CSF (has cilia)

Question 14

Microglia

Answer 14

(in CNS) Phagocytize

Question 15

Oligodendrocyte

Answer 15

(in CNS) Form myelin in CNS (NOT SCHWANN)

–> What is attacked in MS

Question 16

Protoplasmic Astrocytes

vs. Fibrous Astrocytes:

Answer 16

Protoplasmic are Present in Gray Matter of CNS

Fibrous are in White Matter of CNS

Both:

• FORM BLOOD BRAIN BARRIER by telling capillary endothelial cells to form zona occludins
• KEEP CNS STRUCTURE
• Regulate PH
• Regulate immune response by contact w/ capillary endothelium (again, BBB!)
• Sequester Neurotransmitters

Question 17

Meninges are Made of:

Answer 17

1. Dura Mater: Dense Connective Tissue around CNS to protect brain
2. Acrachnoid Matter: Web-like fibers
3. Sub Arachnoid Space: Filled with CSF made in Choroid Plexus by special Ependymal cells
4. Pia Matter: thin clear covering of cerebral cortex

Question 18

How are the ventricular systems of the cerebral cortex and the central canal connected?

Answer 18

3rd and 4th ventricles of the cerebral cortex connect to choroid plexus which connects to the central canal

Question 19

Dorsal Root Ganglion

Answer 19

pseudopolar cells. These motor axons branch from PNS and send signals to CNS via Dorsal root

Question 20

Sympathetic Ganglia Chain

Answer 20

Part of Automatic Nervous system of PNS. Runs parallel spinal cord in THORACIC column. Signals for fight or flight

-Each Ganglia has lots of synapses

Question 21

Parasympathetic

Answer 21

Part of PNS. Axons originate from Cranial and Sacral regions of spine and actually go within organs to innervate them. “Rest and Digest”

Question 22

How does the anatomy of innervation differ in Parasympathetic vs. Sympathetic

Answer 22

Sympathetic:

• SHORT Preganglionic located in thoracic spine
• then innervate sympathetic ganglion
• Which innervates the post synaptic ganglion
• which then goes out close to target

Parasympathetic:

• LONG Preganglionic located in Cranial and Sacral Spine
• then have axons that extend to post synpatic neuron located within to target

Question 23

Submucosal Plexus of Enteric System

Answer 23

Sense PH, regulate glands of the ducts

Question 24

Myenteric Plexus of Enteric System

Answer 24

Regulate Gut muscle movement

Question 25

Why is enteric system part of automatic system?

Answer 25

Enteric system is connected to the sympathetic nervous system (however when these are cut can still function to a certain degree)

Question 26

How do Dorsal Root Ganglion and Sympathetic Ganglions differ?

Answer 26

Sympathetic ganglions have synapses

Dorsal Root Ganglions have cell bodies which make them Pseudounipolar neurons!

Question 27

Peripheral Nerve Myelination vs. CNS Nerve Myelination

Answer 27

PNS = Schwann cells. Each axon gets myelinated

CNS = Oligodendrites
multiple axons myelinated together

Question 28

Charcot-Marie-Tooth Disease

Answer 28

Damage of Schwann Cell myelination in PNS

Question 29

Wallerian degeneration

Answer 29

intentional axon destruction