Lecture 2

Question 1

Afferent/Sensory

Answer 1

incoming

-fibers transmit impulses from receptors to CNS (central nervous system)

Question 2

Efferent/Motor

Answer 2

outgoing

-efferent fibers transmit impulses from the CNS to effector organs

Question 3

ATPase

Answer 3

the enzyme located on the myosin head that breaks down ATP to yield adenosine diphosphate (ADP), inorganic phosphate (Pi), and energy

Question 4

Eccentric

Answer 4

• muscles lengthen while producing force
• cross-bridges form but sacromere lengthens
  (i. e. down phase of a squat)

Question 5

Concentric

Answer 5

• muscle shortens while producing force
• most familiar type of contraction
• sacromere shortens, filaments slide toward center

Question 6

Excitatory Postsynaptic Potential (EPSP)

Answer 6

excitatory impulse causes depolarization and promotes AP

• temporal summation
• spatial summation

Question 7

Temporal Summation

Answer 7

summing several EPSPs from one presynaptic neuron: more depolarizing

Question 8

Spatial Summation

Answer 8

summing from several different presynaptic neurons

Question 9

Inhibitory Postsynaptic Potential (IPSP)

Answer 9

inhibitory impulse causes hyperpolarization and prevent AP

Question 10

Sympathetic System (division of autonomic)

Answer 10

fight or flight; prepares body for exercise
-includes increased: heart rate, blood pressure, blow flow to muscles, airway diameter, metabolic rate, glucose levels, FFA levels, mental activity

Question 11

Parasympathetic System (division of autonomic)

Answer 11

rest and digest; active rest, opposes sympathetic effects

• conserves energy
• increased: digestion, urination
• decreased: heart rate, diameter of airways and blood vessels

Question 12

Autonomic System

Answer 12

• regulates visceral activity
• control involuntary internal functions
• exercise related autonomic regulation: heart rate, blood pressure, lung function

Question 13

Divisions of Autonomic System (2)

Answer 13

Sympathetic

Parasympathetic

Question 14

Free Nerve Endings (5)

Answer 14

Mechanoreceptors: physical forces
Thermoreceptors: temperature
Nociceptors: pain
Photoreceptors: light
Chemoreceptors: chemical stimuli

Question 15

Depolarization

Answer 15

decrease in the electrical potential (charge becomes more positive than the RMP of -70) across a membrane, as when the inside of a neuron becomes less negative relative to the outside.

• reaches about +40 mV
• more Na+ channels open, Na+ diffuses into cell

Question 16

Resting Membrane Potential (RMP)

Answer 16

electrical potential of -70 mV inside of a cell membrane

-caused by uneven separation of (2K+ and 3Na+ )ions across the membrane

Question 17

Repolarization

Answer 17

returning to resting membrane potential

• K+ leaves cell rapidly
• Na+ channels close

Question 18

Hyperpolarization

Answer 18

increase in the electrical potential across a membrane

• more K+ channels open, K+ leaves the cell
• makes it more difficult for nerves impulses to rise

Question 19

Acetylcholine (ACh)

Answer 19

primary neuron transmitter for motor neurons the innervate skeletal muscle and parasympathetic autonomic neurons

Question 20

Norepinephrine (NE)

Answer 20

primary neurotransmitter or most sympathetic autonomic neurons

Question 21

Stretch-reflex

Answer 21

central region of an infrafusal fiber that cannot contract, only stretch, because it contains no or only a few actin and myosin filaments
-reaction of the muscle spindles when stretched