Ch. 41: Neural Signaling

Question 1

a change in an organisms environment

Answer 1

stimulus

Question 2

hormones that are regulated and produced to trigger chemical rxn

Answer 2

endocrine system

Question 3

neurons send electrical signals to target cells to trigger rxns

Answer 3

nervous system

Question 4

reception..transmission..integration..action

Answer 4

RTIA (response to a stimulus)

Question 5

the process of detecing a simulus

Answer 5

reception

Question 6

sending messages to a neuron

Answer 6

transmission

Question 7

sorting and interpreting incomig sensory info and determining the appropriate response

Answer 7

integration

Question 8

the physical/physiological response that an effector carries

Answer 8

action

Question 9

specialized cells in the nervous system
- receive stimuli
- produce & transmit electrical signals (action potentials)
- have 3 main parts:
-cell body, axon, dendrites

Answer 9

neurons

Question 10

contains nucleus, organelles, and bulk of cytoplasm

Answer 10

cell body

Question 11

long extension from the neuron that conducts nerve impulses away from the cell body

Answer 11

axon

Question 12

short, highly branched processes specialized to receive stimuli

Answer 12

dendrites

Question 13

“nerve glue” cells

Answer 13

neuroglia (glial cells)

Question 14

phagocytic cells that remove debris and waste

Answer 14

microglia

Question 15

star-shaped cells that support neurons physically/metabolically

Answer 15

astrocytes

Question 16

line fluid-filled spaces in the brain & spinal cord & produce cerebrospinal fluid

Answer 16

ependymal cells

Question 17

form a myelin sheath around the axon which insulates axons and speeds up the rate of impulse transmission

Answer 17

oligodendrocytes

Question 18

similar to oli but form myelin sheaths in the peripheral nervous system

Answer 18

schwann cells

Question 19

group of cell bodies

Answer 19

ganglion

Question 20

used to transmit info along axons
- inside is negatively charged (-70mv) (ions can’t cross membranes)

Answer 20

neural signals

Question 21

the plasma membrane of a __ doesn’t get an impulse and is polarized

Answer 21

resting neuron (the neural signals category)

Question 22

the voltage of a resting neuron is

Answer 22

negative (-70mv)

Question 23

• selective permeable (no ions)
• sodium-potassium pumps (sodium channels open is first = depolarization; potassium channels open is second = repolarization)
• passive ion channels
• large intracellular anions (can’t cross plasma membrane/contribute negative charge)

Answer 23

how does a neuron maintain a negative resting potential

Question 24

opening of Na channels/make less negative

Answer 24

depolarization

Question 25

making more negative back to resting potential

Answer 25

repolarization

Question 26

below resting potential

Answer 26

hyperpolarization

Question 27

action potential (ALL OR NONE)

Answer 27

-55mv

Question 28

resting potential

Answer 28

-70mv

Question 29

small period of time where neuron can't respond

Answer 29

refractory period

Question 30

voltage reaches threshold, voltagte gated Na channels open, Na goes into cell and K channel opens slowly in response

Answer 30

depolarization to repolarization

Question 31

1. resting potential 2. threshold 3. depolarization phase 4. repolarization phase 5. undershoot

Answer 31

action potential cycle

Question 32

wave of action potential along an axon

Answer 32

impulse

Question 33

1. contiguous conduction - smooth/in unmyelinated neurons 2. saltatory conduction - depolarization jumps

Answer 33

neural impulse transmission

Question 34

space between neurons 1. chemical __ - have a synaptic cleft - involve the release of neurotransmitters

Answer 34

synapse

Question 35

__ terminal release neurotransmitters

Answer 35

synaptic

Question 36

chemical that transmit signals from one neuron to another neuron or to an effector

Answer 36

neurotransmitters

Question 37

1. nerve impulse (action potential) reaches axon terminal and calcium channels open and Ca flow into the cell from the outside 2. Ca ions stimulate fusion os synaptic vesicles with the pre-synaptic membrane which release a neuro transmitter into the synaptic cleft 3. the neurotransmitter diffuses across the cleft and binds to receptors int he post-syn membrane 4. this initiates the opening of sodium or potassium channels n the dendrites of post-synaptic neuron which changes the membranes potential (depolar/hyperpolar 5. the neurotransmitter chemical is broken down by an enzyme which release sit from the binding sites and the new cycle begins (ex: acetylcholine is broken down by acetylcholinesterase) (ase=enzyme) 6. Ca is returned to the outside of the presyn membrane by a calcium pump

Answer 37

steps in synaptic transmission

Question 38

point at which a muscle and neuron meet (neuromuscular junction)

Answer 38

motor end plate (sending messages to effectors)

Question 39

1. acetylcholine: excititory in skeletal muscle , inhibitory in cardia muscles (most important) 2. norepinephrine, 3. dopamine, 4. seratonin, 5. endorphins

Answer 39

neurotransmitters

Question 40

depolarization (less negative) by opening of Na channel that lead to Na influx (increase) (never reach threshold)

Answer 40

EPSP

Question 41

hypolarization (more negative) by opening of K channels that lead to K efflux (decrease)

Answer 41

IPSP

Question 42

allow CNS (central nervous system) to integrate incoming info from various sources (brain, spinal cord, etc...)

Answer 42

neural circuits

Question 43

opposite of neural circuits

Answer 43

neural circuits divergence