Unit 1 Exercise Physiology

Front 1

motor unit

Back 1

motor unit and all the muscle cells it services, basic functional unit of the muscle

Front 2

neurons and muscle cells are electrically activated by

Back 2

changing their electrical charges

Front 3

NT

Back 3

chemicals released by a neuron which cause excitation, facilitation, or inhibition

Front 4

neuron activations are

Back 4

waves of depolarization caused by Na+ influx

Front 5

chemical gates

Back 5

least numerous, found in nerve cell body and dendrites, and muscles at nerve synapse; unlocked by NT

Front 6

electrical gates

Back 6

most numerous, found in neuronal axons, found distal to synapses in muscle cells, open when resting membrane potential exceeds threshold

Front 7

the opening of electrical gates that causes

Back 7

necessary level of depolarization called AP

Front 8

the nerve impulse must _______ before another impulse can be sent down an axon

Back 8

repolarize

Front 9

repolarization requires

Back 9

energy ATP to repolarize

Front 10

the Na, K pump requires

Back 10

ATP for pump

Front 11

facilitation

Back 11

raising the resting potential above the normal potential, increasing likelihood that NT release cause exceeding threshold

Front 12

inhibition

Back 12

lowering resting potential below normal potential, decreasing likelihood of reaching potential

Front 13

most common excitatory and facilitory NT

Back 13

Norepi and Acetylcholine

Front 14

most common inhibitory NT

Back 14

GABA

Front 15

spatial summation

Back 15

NT release from more than one neuron is necessary to cause excitation

Front 16

temporal summation

Back 16

altering frequency of a nerve firing, to ensure sufficient amounts to cause depolarization

Front 17

rate coding

Back 17

temporal summation occurs in skeletal muscles

Front 18

tetanus

Back 18

muscle achieve maximal temporal summation

Front 19

safety net for muscle groups

Back 19

inhibition for muscle groups

Front 20

can't be overstimulated to perform

Back 20

fine motor skills

Front 21

nerve failure

Back 21

When a nerve fails to activate its target through some mechanism other than inhibition.

Front 22

fatigue.

Back 22

When the nerve fails to activate a muscle then the condition is generally referred to

Front 23

3 main causes of nerve failure (neuronal based fatigue)

Back 23

neuron don't repolarize; neuron don't release NT; Branch Point Failure

Front 24

1. Neuron does not repolarize

Back 24

Repolarization requires an active Na-K pump. The Na-K pump needs energy (ATP) to operate. Therefore, if the ATP is “used up", the neuron can not repolarize and hence fails

Front 25

Neuron does not repolarize; identified by

Back 25

finding high post-exercise serum potassium levels

Front 26

when neuron don't repolarize

Back 26

condition usually will occur with high stimulation frequencies or rapid temporal summation

Front 27

2. Neuron does not release neurotransmitter.

Back 27

Neurotransmitter is made and stored in packets in the synaptic end bulb. If neurotransmitter release occurs faster than the rate at which it is being made, the neuron will eventually "run out" of neurotransmitter. With no transmitter, even if the neuron depolarizes, the target will not be activated.

Front 28

how will neuron not releasing NT will occur

Back 28

with high stimulation frequencies or rapid temporal summation; (not releasing NT)

Front 29

3. Branch Point Failure

Back 29

Most neuronal axons have branches of varying lengths (esp. motor neurons). When a neuron is being stimulated at high frequencies, some of the longer branches can not repolarize as fast as the rest of the axon. Thus when the neuron is activated again, some of the branches can't depolarize because they have not repolarized yet.

Front 30

all 3 nerve failures occur with

Back 30

(all 3) high stimualtion frequencies or rapid temporal summation