Neurons + Nerves Overview

Question 1

nuclei

Answer 1

collections of cell bodies of CNS

Question 2

tracts

Answer 2

collections of nerve axons of CNS

Question 3

cranial nerves

Answer 3

• project from brainstem

- innervate face, head, neck

Question 4

spinal nerves

Answer 4

• project from either side of spinal chord

- innervate rest of body

Question 5

ganglia

Answer 5

• collections of cell bodies of PNS

- each ganglia = part of a single nerve

Question 6

nerves

Answer 6

• in PNS

- hundreds of thousands of axons wrapped together in connective tissues

Question 7

neurons

Answer 7

• nerve cells that conduct electrical impulses and relay info thru body
• 3 basic parts: dendrites, cell body, axon
• do not undergo mitosis (survive a person’s entire lifetime, dead ones cannot be replaced, die quickly w/out Oxygen)

Question 8

dendrites

Answer 8

• receiving end of neuron
• numerous short extensions emanating from cell body
• receive impulses from other neurons
• conduct that info toward cell body

Question 9

cell body of neuron

Answer 9

• contains nucleus, all usual organelles except centrioles (bc no mitosis)
• main function = produce neurotransmitters

Question 10

axon

Answer 10

• conducts impulses away from cell body to axon terminals

- composed of cell components but no rough ER, meaning it must get its necessary proteins from the cell body

Question 11

neurotransmitters

Answer 11

• chemicals stored inside axon terminal vesicles at end of axon terminals
• when released, carry transmission of nerve impulse across synapse form one neuron to another

Question 12

synapse

Answer 12

gap between two neurons

Question 13

excitatory interneurons

Answer 13

send excitatory signals to motor neurons, causing muscle contraction

Question 14

inhibitory interneurons

Answer 14

send inhibitory signals to motor neurons, preventing muscle contraction