((L.E#1)) Lecture 1 : Nervous System

Question 1

Nervous System
-dept

Answer 1

• Neurology

Question 2

Nervous System Functions…

Answer 2

1. Sensory: monitors changes (vision, hearing, taste, smell)
2. Motor Functions: control muscles + glands
3. Integration: interpreting
4. Homeostasis: maintaining internal state (H.R, peristalsis, respiratory rate)

Question 3

Type of Anatomical Divisions

Answer 3

1. CNS = Central Control Nervous System
2. PNS = Peripheral N.S (outside CNS)

Question 4

CNS:

Answer 4

CNS = Central Control Nervous System
- brain + spinal cord

Question 5

PNS:

Answer 5

PNS = Peripheral N.S (outside of the CNS)

• 12 pairs of cranial nerves (connect to brain + optic nerves)
• 31 pairs of spinal nerves (connect to spinal cord)
• communication between CNS and rest of body

Question 6

2 Functional (how they work) Subdivisions of PNS:

Answer 6

1. Sensory (afferent):

• Somatic (body) Sensory: sensory impulses from skin, skeletal muscles, or joints.
  (receptor > CNS)
• deals with visceral (organs) sensory: such as heart, stomach, intestines
  (sensory > CNS)

2. Motor (efferent):
   (CNS > muscles or glans)

• Somatic Motor: motor to skeletal muscle (voluntary)
• ANS (autonomic n.s): CNS to cardiac muscle (involuntary)

Question 7

Motor (efferent) subdivisions:

Answer 7

1. Sympathetic N.S
   - fight or flight stress
2. Parasympathetic N.S
   - rest & digest
   - not stressed + normal H.R

Question 8

Nervous Tissue
- cell types

Answer 8

1. Neuroglia (glial cells)
2. Neurons

Question 9

Neuroglia (glial cells) :

Answer 9

• Mitotic (can cell divide)
• Nonconductor (no nerve impulse)
• Bind, protect, support neurons

Question 10

Neuroglia (glial cells)
- type of glial cells

Answer 10

1. Microglial Cells: small oval cells, found in CNS, phagocytize microbes/nueronal debris, deals with immunity
2. Astrocytes: star like cells, scar tissue
   found in CNS, exchange between capillaries/neurons, most abundant cells in CNS
3. Ependymal Cells: line cavities in the brain+spinal cord, help circulate CSF (cerebrospinal fluid) “cushion like”, CNS
4. Oligodendrocytes: myelin sheath around axons in CNS
5. Satellite Cells: located in the PNS, bind neurons
6. Schwann Cells: located in PNS, myelinate axons in PNS, secrete substances to promote regeneration of axons in PNS

Question 11

Does the CNS have schwann cells ?

Answer 11

No which means no regeneration of axons

ex: snap of neck = permanent damage

Question 12

Quadriplegia:
Paraplegia:

Answer 12

• all 4 limbs
• lower limbs

Question 13

Neurons:

Answer 13

• not mitotic
• aging (<) neurons
• high metabolic rate = glucose + oxygen

Question 14

Structure of a Neuron:

Answer 14

1. Cell body: contains nucleus, has DNA, “control center”
2. Dendrites: have receptors for sensory
3. Axon: conduct action potentials (nerve impulse) away from cell body
   -bundle of axons in CNS = tracts
   -bundle of axons in PNS = nerve

Question 15

Neurotransmitter:

Answer 15

at the end of an axon there will be axon terminals which secrete NT to connect to the next neuron by crossing a synapse (gap)

Question 16

Myelin :

Answer 16

fatty coating that insulates axons
-myelinated = white + rapid conduction

-unmyelinated = gray + slower conduction

Question 17

Problems with Myelin
- M.S (multiple sclerosis)

Answer 17

MS: an autoimmune disorder where your antibodies attack myelin on the axons = destroys myelin + CAUSES them to harden into lesions (scleroses)

• RESULTS in slowed down action potentials OR to stop = blindness, muscle weakeness, paralysis, urinary incontinence

NO CURE but there are treatments

Question 18

Axon and or neurons need to have what?

Answer 18

continual glucose and O2 supply

Question 19

Hypoglycemia:

Answer 19

overdose of insulin
-decreases blood glucose levels = decrease ATP synthesis in the brain –> results in slow impulse conduction