Neuromuscular Control

Question 1

What is resting membrane potential

Answer 1

-70mV (if you don’t get this, just leave)

Question 2

cytosol has what charge relative to ECF

Answer 2

negative

Question 3

what goes in a cell?

Answer 3

K+

Question 4

what goes out

Answer 4

Na+ and Cl-

Question 5

membrane potential causes neurons and myocytes to:

Answer 5

receive info
transmit info
integrate info

Question 6

how much is needed to open Na-K Pump?

Answer 6

10-15mV

Question 7

Depolorization makes membrane become?

Answer 7

+30mV

Question 8

what happens when K+ out

Answer 8

hyperpolarizes

Question 9

what determines nerve conduction velocity?

Answer 9

fiber size and presence of myelin

Question 10

how does a larger diameter affect nerve conduction velocity?

Answer 10

less resistance, faster conduction

Question 11

What does myelin do?

Answer 11

speeds conduction from 200m/s

Question 12

Excitatory Post-Synaptic Potentials

Answer 12

Na+ increased

Question 13

Inhibitory Post-Synaptic Potentials

Answer 13

Na+ decreased, Cl- increased

Question 14

what is the basic functional unit of skeletal muscles?

Answer 14

motor units

Question 15

what happens with motor unitys with smaller neuron cell bodies

Answer 15

recruited first

Question 16

How does the thalamus control movement?

Answer 16

contains relay pathways from cerebellum, basal ganglia, superior colliculus to motor cortex
contributes to motor generation and self-monitoring

Question 17

how does the hypothalamus control movement?

Answer 17

regulates internal environment to maintain homeostasis; temp, BP, HR, contractility, respiration, digestion, fluid balance, emotion, neruodocrines, sleep-wake, appetite, thirst

Question 18

how does the cerebellum control movement?

Answer 18

receives visual and proprioceptive input; compares actual movement to motor plan; generates corrective responses
coordinates the timing and sequencing of mus activity, smoothing movement

Question 19

how does the brain stem control movement?

Answer 19

autonomic regulatory centers for respiratory and cardiovascular centers;
reticular system- coordinates mus fxn, maintains mus tone, contributes to sleep-wake and consciousness, pain control

Question 20

Sensory System

Answer 20

transmits info from sensory organs, skin, blood and lymph, tendons, and muscles to central somatosensory areas.

Question 21

Motor System: Pyramidal

Answer 21

corticospinal and coritcobulbar tracts
innervate motor neuron in spinal cord and brainstem
involved in voluntary movement.

Question 22

Motor System: Extrapyramidal

Answer 22

primarily located in reticular formation; modulated by cortex, cerebellum, basal ganglia, involved in reflexes, postural control, and coordination of movement

Question 23

Sympathetic NS

Answer 23

fight fight fight or flight

control HR, vasculature, and respiration

Question 24

Parasympathetic NS

Answer 24

feed and breed

promotes synthesis of glycogen

Question 25

Neuromus physiological adaptation due to resistance training

Answer 25

• increase motor unit firing rate
• increase motor unit recruitment
• increase motor unit synchronization
• increase reflex neural facilitation
• increase coordination of antagonist mus
• inhibition of Golgi tendon organs (autogenic inhibition)

Question 26

Neuromus functional result of resistance training

Answer 26

• increase rate of force development
• increase force production and duration
• increase force producation and efficiency
• increase rate of force development*
• disinhibits max contraction

Question 27

contractile adaptation: physiological response to resistance training

Answer 27

• increase mus mass
• increase CSA
• increase type II fiber area
• increase intracellular lipid contact
• increase ATP utilization rate

Question 28

contractile adaptation: functional result of resistance training

Answer 28

• increase strength
• increase contractile capacity
• increase strength (selective recruitment)
• increase metabolic capacity
  increase max contraction capacity

Question 29

Elastic Adaptations to Resistance Training: Series Elastic Components

Answer 29

• tendons and myocytes crossbridges

- translate stretch into force

Question 30

Elastic Adaptations to Resistance Training: Parallel Elastic Components

Answer 30

• collagenous structures

- stabilize and protect muscle

Question 31

Elastic Adaptations to Resistance Training: stretch-shortening cycle

Answer 31

stretch creates potential energy that can enhance forces produced by contractile elements

Question 32

Hypertrophy

Answer 32

protein is degraded when subjected to mechanical overload
stims molecular pathways that favor protein syn
this increases the size and amount of contractile elements and #sarcomeres in parallel
augments diameter of individual fibers resulting in an INCREASE IN CROSS SECTIONAL AREA and strength

Question 33

What happens to excess protein

Answer 33

oxidized –> urea formation –> dehydration and diuresis

Question 34

Hyperplasia

Answer 34

overload may stim proliferation of myocytes from satellite cells

Question 35

overload

Answer 35

mus tension must be developed at adequate intensity and duration

Question 36

immobilization

Answer 36

changes occur within hours

• decreases in protein synthesis
• loss mus mass and contractile/SR
• 3-4% strength loss daily in first week

Question 37

Aging

Answer 37

mus mass peaks b/n 25-30 yo
loss ~8% per decade
fiber atrophy, fiber loss, motor unit remodeling