nervous system: functions&cellular composition

Question 1

divisions of the nervous system

Answer 1

central nervous system (CNS)
peripheral nervous system (PNS)

Question 2

3 functions of the nervous system

Answer 2

-sensory nerves gather info and carry it to the CNS
-inter nerves process or interpret the information brought to the CNS by the sensory nerves
-motor nerves convey info from the CNS to the muscles and glands to carry out the plans made by the CNS

Question 3

neuroglia or glial

Answer 3

-most abundant type
-support, protect, insulate, nourish, and generally care for neurons

Question 4

neurons

Answer 4

-do the communicating for the nervous system
-long shape makes them delicate
-cannot regenerate

Question 5

types of neuroglia

Answer 5

-astrocyte: most abundant, feeds microglia
-microglia: fights off bacteria (phagocytosis)
-ependymal cells: produces cerebral spinal fluid
-schwann cells: produces myelin for PNS
-oligodendrocytes: produces myelin for CNS

Question 6

structure of a neuron

Answer 6

-cell body
-dendrites
-axon
-axon terminals

Question 7

axon

Answer 7

-myelin sheath
-nodes of ranvier (not covered by myelin)
-neurilemma
-axon terminal

Question 8

what is afferent neurons?

Answer 8

they carry information from the periphery toward the CNS

Question 9

what are efferent neurons?

Answer 9

carry information from CNS toward periphery

Question 10

3 types of neurons
are they afferent or efferent?

Answer 10

sensory- afferent
motor- efferent
inter- connect sensory and motor nerves, only in CNS

Question 11

white matter

Answer 11

made up of myelinated axons

Question 12

gray matter

Answer 12

-unmyelinated axons
-cell bodies
-inter neurons
-synapses

Question 13

nerve impulse

Answer 13

-aka action potential
-electrical signals convey information along a neuron
-move along sensory or motor neurons

Question 14

polarization

Answer 14

resting state
-inside of the neuron is more negative than the outside when it’s polarized

Question 15

depolarization

Answer 15

stimulated state
-change inside the cell from - to + when the neuron is stimulated

Question 16

repolarization

Answer 16

return to resting
-inside of cell becomes negative again

Question 17

what causes the nerve impulse?

Answer 17

polarization
-K+ leaks from neuron
depolarization
-Na+ rushes in
repolarization
-K+ rushes out

Question 18

action potential

Answer 18

-forms at axons beginning
-regenerates along axon’s length
-enters axon terminal
-releases ACh from vesicles

Question 19

what causes the nerve impulse to move quickly?

Answer 19

-myelin insulates axon
-myelin exposes some axonal membrane— nodes of ranvier
-action potentials jump quickly from node to node like a kangaroo
-this affect of jumping increases speed of the action potential

Question 20

synaptic cleft

Answer 20

-receptors
-neurotransmitters
-inactivators

Question 21

what happened in synapse

Answer 21

ACh is:
-secreted from neuron A
-diffused across synaptic cleft
-bound to receptors in neuron B
neuron B is activated