Neuromuscular Control

Question 1

What helps to maintain the resting membrane potential?

Answer 1

• negatively charged cytosol
• K+ intracellularly
• Na+ and Cl- extracellularly

Question 2

Alterations in resting membrane potential are how neurons and myocytes:

Answer 2

receive, transmit, and integrate info with themselves and other cells

Question 3

Depolarizing is to:

Answer 3

make less negative by opening Na+ channels

Question 4

Repolarizing is to:

Answer 4

make more negative by opening K+ channels and inactivating Na+ channels

Question 5

Hyperpolarizing is to:

Answer 5

make more negative than threshold by K+ channels still being open and Na+ channels in resting state

Question 6

What determines the velocity at which APs are propagates along cell membranes?

Answer 6

fiber diameter and presence of myelin

Question 7

A larger fiber results in:

Answer 7

lower resistance so faster conduction

Question 8

Presence of myelin results in:

Answer 8

AP skip from node to node (saltatory conduction) and speeds conduction

Question 9

What are graded potentials?

Answer 9

potentials in post-synaptic membrane that are proportional to stimulus strength

Question 10

How are graded potentials propagated? APs?

Answer 10

GP: ion channels
AP: voltage gated Na and K channels

Question 11

Where can graded potentials occur?

Answer 11

any membrane region that receives sensory stimuli

Question 12

What motor units are recruited first?

Answer 12

those with smaller neuron bodies–type I

Question 13

What neurotransmitter is released at the NMJ?

Answer 13

Ach

Question 14

What does the thalamus contain?

Answer 14

relay pathways from cerebellum, basal ganglia, and superior colliculus to motor cortex

Question 15

What does the thalamus contribute to?

Answer 15

motor generation and self-monitoring

Question 16

What does the hypothalamus regulate?

Answer 16

internal environment to maintain homeostasis

-temp, BP, HR, contractility, respiration, digestion, fluid balance, emotion, neuroendocrines, sleep, thirst

Question 17

What does the cerebellum do?

Answer 17

• receive visual and proprioceptive input
• compare actual movement to motor plan
• generate corrective responses
• –coordination and sequencing muscle activity

Question 18

Function of brain stem:

Answer 18

autonomic regulatory centers for respiratory and cardiovascular centers

Question 19

Functions of reticular system (brain stem):

Answer 19

• coordinate muscle function
• maintain muscle tone
• contributes to sleep-wake and consciousness
• pain control

Question 20

Function of peripheral sensory system:

Answer 20

transmit info from sensory organs, skin, blood and lymph vessels, tendon, and muscle to central somatosensory areas

Question 21

What receptors of the peripheral sensory system help transmit info?

Answer 21

• mechano
• thermo
• noci
• photo
• chemo

Question 22

What tracts are part of the pyramidal motor system?

Answer 22

corticospinal and corticobulbar

Question 23

Function of pyramidal motor system:

Answer 23

innervate motor neuron in spinal cord and brainstem

-involved in voluntary movement

Question 24

Where is the extrapyramidal motor system located?

Answer 24

reticular formation of brain stem

Question 25

What is the extrapyramidal motor system modulated by?

Answer 25

cortex, cerebellum, and basal ganglia

Question 26

What is the extrapyramidal motor system involved in?

Answer 26

reflexes, postural control, coordination of movement

Question 27

Why is the sympathetic system important when considering exercise?

Answer 27

effects on HR, vasculature and respiration

Question 28

What does the parasympathetic system promote the synthesis of?

Answer 28

glycogen