Ch 12

Question 1

Nervous Tissue definition

Answer 1

tissue replaced for rapid transformation of signals from cell to cell.
Works along with the Endocrine System to coordinate homeostasis and body activites.

Question 2

CNS

Answer 2

Brain and Spinal Cord

Question 3

Autonomic Nervous System

Answer 3

sympathetic (fight or flight)
parasympathetic (rest and digest)

Question 4

Astrocytes

Answer 4

located in CNS
provide Nutrional support and the proper chemical environment to Neurons

Question 5

Oligodendrocytes

Answer 5

in CNS
produce myelin sheaths

Question 6

Microglia

Answer 6

in CNS
mobile macrophages

Question 7

Ependymal Cells

Answer 7

in CNS
line brain ventricles of the Brain
produce CSF

Question 8

Schwann cells

Answer 8

in PNS
produce Myelin sheaths

Question 9

Neurolemma

Answer 9

the outermost layer of cell, contains nucleus

Question 10

Satellite cells

Answer 10

in PNS
nutritional support

Question 11

Resting Membrane Potential

Answer 11

electrical potential across the axon membrane
outside is positive, inside is negative
extracellular area has more Sodium and Chloride ions
the intracellular area has more potassium ions, phosphate, and amino acids
RMP is approx. equal to -70

Question 12

Voltage-Gated Channels

Answer 12

located in the axolemma
open and close in response to changes in voltage
ex: voltage-gated Na+ channels
voltage-gated K+ channels

Question 13

Sodium/Potassium ATPase Pumps

Answer 13

located in axolemma
takes care of ion Na+ and K+ leakage across the axon membrane

Question 14

Depolarization

Answer 14

voltage-gated Na+ channels open in response to a stimulus the membrane voltage becomes more positive and positive ions rush inside the membrane
depolarization originates at Axon Hillock

Question 14

Repolarization

Answer 14

recovery of the RMP

Question 15

Action Potential

Answer 15

Depolarization + Repolarization
electrical signal that is propagated down the axon

Question 16

Threshold Stimulus

Answer 16

any electrical stimulus that is strong enough to initiate as action potential

Question 17

Continuous Conduction

Answer 17

propagation of nerve impulse in a step by step depolarization and repolarization of adjacent areas of sarcolemma

Question 17

All or none principle

Answer 17

initial stimulus must reach threshold before an action potential is generated. Initial electrical stimulus will quickly dissipate if the threshold stimulus is not achieved.

Question 18

Saltatory Conduction

Answer 18

(sends signal over)
action potential is moved along the myelinated portion of axolemma, passing through the node until the impulse reaches synapse
associated with myelinated neurons