Human Body Lecture Test 2 (Nervous System)

Front 1

CNS

Back 1

brain and spinal cord

Front 2

cranial nerves

Back 2

12 pairs

Front 3

Spinal nerves

Back 3

31 pairs

Front 4

Somatic Nervous System

Back 4

-voluntary, nervous system, concious control
-skeletal muscles

Front 5

Autonomic Nervous System (ANS)

Back 5

-involuntary nervous system
-2 divisions: sympathetic and parasympathetic

Front 6

Sympathetic Division

Back 6

THE E DIVISION
-exercise, excitement, emergency,embarrassment
-"Flight or Fight"

Front 7

Parasympathetic Division

Back 7

THE D DIVISION
-digestion, defecations, diuresis (urination)
-"Breed and Feed"

Front 8

excitability

Back 8

respond to changes in stimuli and produce electrical signals

Front 9

conductivity

Back 9

can transfer the impulse along the neuron

Front 10

Neuroglia / Glial Cells
6 Types

Back 10

supporting cells
half of the mass of the brain
don't conduct nerve impulses
(no excitability/conductivity)

Front 11

Astrocytes

Back 11

attach neurons to capillaries, control chemical environment (ions, neurotransmitters) around neuron
physical support

Front 12

Microglial cells

Back 12

monitor health of neurons and transform into macrophages to engulf microorganisms and debris to protect neurons

Front 13

Ependymal Cells

Back 13

circulate cerebrospinal fluid

Front 14

oligodendrocytes

Back 14

produce myelin sheaths in CNS

Front 15

Schwann Cell

Back 15

form myelin sheaths around large nerve fibers in PNS

Front 16

Satellite Cells

Back 16

function like astrocytes, but in PNS

Front 17

Neurons

Back 17

specialized cells that conduct nerve impulses
very long lived
lose ability to divide
high metabolic rate

Front 18

Biosynthetic Center

Back 18

cell body - cytoplasm and nucleus

Front 19

nuclei

Back 19

cluster of nerve cell bodies within CNS

Front 20

Ganglia

Back 20

clusters of cell bodies along the nerves of the PNS

Front 21

Dendrites

Back 21

receive signals from other neurons
highly branched
conduct towards cell body over short distances

Front 22

Axons

Back 22

generate and conduct electrical signals away from the cell body, 1 per neuron

Front 23

Nodes of Ranvier

Back 23

gaps between adjacent Schwann cells on the axon, unmyelinated

Front 24

sensory (afferent) neurons

Back 24

from skin or internal organs to CNS
cell bodies usually in ganglia

Front 25

motor (efferent) neurons

Back 25

impulses from CNS to effector organs
cell bodies usually in CNS

Front 26

interneurons (association) neurons

Back 26

impulse from sensory to motor neuron
within CNS
99% of neurons in body
most are multipolar

Front 27

Average Resting Membrane Potential for Neurons:

Back 27

-70mV (-40mV to -90mV)

Front 28

graded potentials

Back 28

short-lived, local changes in membrane permeability, short distance

current flow decreases with distance, degrades

Front 29

depolarization

Back 29

inside of the membrane becomes less negative
increases the chance of a nerve impulse

Front 30

hyperpolarization

Back 30

inside of cell becomes more negative
decreases the probability of a nerve impulse

Front 31

action potentials

Back 31

current flow does NOT decreases with distance
Only occurs in muscle cells and axons of neurons

Front 32

How fast can a nerve impulse travel?

Back 32

100 - 300 ft/sec

Front 33

How much does a typical membrane have to be depolarized to reach threshold

Back 33

15 - 20 mV (happens are about -55mV)

Front 34

What is the total amplitude change during a nerve impulse?

Back 34

-70mV to 30mV, so 100mV total

Front 35

Inactivation Gates

Back 35

Block the voltage-gated sodium channels soon after they open

Front 36

repolarization

Back 36

the inside of the cell becomes more negative (after K+ ion gates open)

Front 37

Absolute refractory period

Back 37

Time following the production of a nerve impulse during which the neuron will NOT respond to a 2nd stimulus

Front 38

Relative refractory period

Back 38

time following the production of a nerve impulse during when it is more difficult to illicit a response

Front 39

How does Novocaine work?

Back 39

block the opening of voltage-gated Na+ channels.

Front 40

Excitatory Neurotransmitters

Back 40

act to increase postsynaptic membrane permeability to Na+

cause EPSPs

Front 41

EPSP's

Back 41

Excitatory Postsynaptic Potentials, local graded depolarization

help bring membrane to threshold

Front 42

Inhibitory Neurotransmitters

Back 42

act to increase membrane permeability to K+ or Cl-
cause IPSPs

Front 43

IPSP's

Back 43

Inhibitory Postsynaptic Potentials, local graded hyperpolarizations

take membrane away from threshold

Front 44

Glutamate

Back 44

excitatory neurotransmitter

Front 45

serotonin

Back 45

inhibitory neurotransmitter

Front 46

acetylcholine

Back 46

excitatory to skeletal muscle, but inhibitory to some visceral organs (heart)

Front 47

Synaptic Integration

Back 47

Summing of all the separate signals coming to a neuron

Front 48

Temporal Summation

Back 48

time, one neuron sends repeated signals

Front 49

Spatial Summation

Back 49

depends of the location of the synapses in relation to the axon

Front 50

anterior horns

Back 50

location of neural cell bodies in the spinal cord

Front 51

ventral roots

Back 51

contain motor (efferent) fibers

Front 52

Dorsal roots

Back 52

contain sensory (afferent) fibers

Front 53

Multiple Sclerosis

Back 53

an autoimmune disease and a "demylination disorder"
myelinated areas on axon in CNS are destroyed and replaced by plaque

Front 54

Why do you get abnormal sensations (tingling) or numbness, uncoordinated during MS?

Back 54

Because the myelin sheath electrically insulates so if it is destroyed you can get random signals.

Front 55

How many neurons are interneurons?

Back 55

99%

Front 56

How many cranial sensory nerves?

Back 56

3

Front 57

How many cranial motor nerves?

Back 57

5

Front 58

How many cranial mixed nerves?

Back 58

4