Lecture 1 : CNS

Question 1

central nervous system

Answer 1

brain and spinal cord

integration and command center

Question 2

Peripheral Nervous system

Answer 2

paired spinal and cranial nerves
carries messages to and from the spinal cord and brain
- has sensory division and motor division

Question 3

Sensory( afferent) Division

Answer 3

Sensory afferent fibers- carry impulses from skin, skeletal muscle and joints to the brain
Visceral afferent fibers- transmit impulses from visceral organs to the brain
( arrives)

Question 4

Motor (efferent) division

Answer 4

transmits impulses from the CNS to the effector organs.

(pathways exit to muscle or glands.

Question 5

2 types of Motor Divsion

Answer 5

Somatic Nervous system- Voluntary system
Autonomic Nervous system- involuntary
- regulates smooth muscle, cardiac muscle and gland

Question 6

ANS

Answer 6

sympathetic - increase in energy (fight or flight)

parasympathetic- decrease in energy ( rest and digest)

Question 7

Two principal cell types of the nervous system

Answer 7

Neurons

supporting cells

Question 8

Neurons

Answer 8

send action potential, electrical signals out to other cells

Question 9

Supporting cells

Answer 9

as a group- glial cells and neuroglia.

Question 10

CNS support Cells

Answer 10

1. Astrocytes
2. microglia
3. ependymal cells
4. oligodrendrocytes

Question 11

PNS support cells

Answer 11

Schwann cells and satellite cells

Question 12

Gangelion

Answer 12

group of neuron cell bodies in the pns ( outside the brain and the spinal cord

Question 13

Astrocytes

Answer 13

• support and brace neurons
• anchor neurons to their nutrient supplies
• wrap around capillaries in the brain- glia limitans
  guide migration of young neurons
  control the chemical environment

Question 14

Microglia

Answer 14

small glial cells

Question 15

Ependymal Cells

Answer 15

line the cavities of the brain and spinal column

Question 16

Oligodendrocytes

Answer 16

branched cells that wrap CNS nerve fibers (myelin

Question 17

Schwann cells

Answer 17

surround fibers of the PNS

Question 18

satellite cells

Answer 18

surround neuron cell bodies within ganglia of the PNS

Question 19

Neurons (nerve cells)

Answer 19

• has a body, axon and dendrites

- long lived, amitotic, and have high metabolic rate.

Question 20

Processes

Answer 20

-arm like extensions from the soma

2 types- dendrites and axons

Question 21

Bundle of Axon

Answer 21

called tract in the CNS

called nerve in the PNS

Question 22

Myelin Sheath

Answer 22

• protects the axon
• electrically insulate fibers from one another
• increase the speed of nerve impulse transmission

Question 23

Axons of the PNS

Answer 23

myelinated by schwann cells

Question 24

Nodes of Ranvier

Answer 24

gaps in the myelin sheath between adjacent schwann cells

Question 25

Axons of the CNS

Answer 25

• myelin sheaths are formed by oligodendrocytes

- no neurilemma

Question 26

Multipolar Neuron

Answer 26

1 axon and many dendrites

- motor neuron, leaves CNS

Question 27

Bipolar Neuron

Answer 27

1 axon and 1 dendrite

-olfaction, vision, hearing ,taste

Question 28

unipolar

Answer 28

1 axon with a receptive end
-general sensations ( skin, skeletal muscles and joints)
Toward the CNS

Question 29

Types of plasma membrane ion channels

Answer 29

• Passive, leakage or channels- does not need stimulus
• chemically gated channels- chemicals cause gates to open
• voltage gated channels
• mechanically gated channels

Question 30

Resting membrane potential

Answer 30

(-70mv) across the membrane of a resting neuron

Question 31

Sodium/ potassium Pump

Answer 31

pumps 3 Na out of the cells and 2K into the cell. trying to maintain a (-) charge inside the cell

Question 32

Depolarization

Answer 32

plasma membrane becomes more positive

Question 33

Repolarization

Answer 33

cell returns to polarized state

Question 34

hyperpolarization

Answer 34

cell becomes extra negative on the inside