Ch 12 Nervous System - Anatomy

Question 1

functions of nervous system

Answer 1

sensory input, integration, motor output

Question 2

sensory input (an example)

Answer 2

information from the joints being sent to brain about body’s position in space

Question 3

integration (an example)

Answer 3

brain compares the info from joints to past experience

Question 4

motor output (an example)

Answer 4

after brain makes it’s calculations, it will send signals to muscles to contract or relax to avoid falling

Question 5

central nervous system

Answer 5

brain and spinal cord
integration and command center

Question 6

peripheral nervous system

Answer 6

paired cranial and spinal nerves

carries messages to and from spinal cord and brain

Question 7

two functional divisions of PNS

Answer 7

sensory (somatic fibers carry impulses from skin skeletal muscle joints to brain, visceral transmits signals from visceral organs to brain)
motor (somatic voluntary movement, autonomic involuntary movement)

Question 8

parts of a neuron

Answer 8

soma (cell body) - input
dendrite - input
axon - conductivity, action potentials
synapse - transmission secretion

Question 9

three classifications of neurons

Answer 9

multipolar
bipolar
unipolar

Question 10

multipolar

Answer 10

most common - interneurons in brain, motor neurons
three or more processes

Question 11

unipolar

Answer 11

mostly sensory nerves in PNS
single process

Question 12

bipolar

Answer 12

rare special sensory neurons (eye, ear, olfactory mucosa)
two processes

Question 13

astrocytes

Answer 13

CNS
most abundant, highly branched
provide scaffolding matrix

Question 14

microglia

Answer 14

CNS
brain immune cells, monitor health of brain
phagocytose bacteria and virus infected cells

Question 15

ependymal cells

Answer 15

CNS
ciliated cells lining ventricles of brain and spinal cord
circulate cerebrospinal fluid (CFS)

Question 16

oligodendrocytes

Answer 16

CNS
branched cells that wrap around the axon of neurons
insulate the cells - myelin sheath

Question 17

Schwann cells

Answer 17

PNS
wrap around axons of neurons and provides insulation and protection
forms myelin sheath
speeds up rate of impulse-salutatory conduction

Question 18

satellite cells

Answer 18

PNS
surround somas in ganglia in PNS
helps regulate environment

Question 19

axons

Answer 19

usually only one unbranched axon per neuron
axon terminal - branched terminus of an axon
rare branches are called collateral if present
long axons are called nerve fibers

Question 20

myelin sheath

Answer 20

whitish fatty (protein lipoid) segmented sheath around most long axons
protects axon, electrically insulates fibers from each other, increase speed of nerve impulse

Question 21

nodes of ranvier

Answer 21

gaps in myelin sheath between adjacent myelinating glia