chapter 7: muscle physiology

Question 1

what are the three different types of muscle?

Answer 1

1. skeletal (attached to bone)
2. cardiac (heart muscle)
3. smooth (digestive system)

Question 2

describe motor unit type 1.

Answer 2

purpose: maintains posture
-slow-twitch oxidative red muscle
-aerobic metabolism
-resistant to fatigue

Question 3

describe motor unit 2A.

Answer 3

purpose: standing/walking
-fast-twitch oxidative red muscle
-anaerobic metabolism
-strength/force but fatigue easily

Question 4

describe motor unit 2B.

Answer 4

purpose: jumping/short duration movement w/ force
-fast-twitch glycolytic white muscle
-anaerobic metabolism
-produces lactic acid (burning sensation)

Question 5

what is a neuromuscular junction?

Answer 5

the synapse connection between the end of a motor neuron and the muscle fiber

-motor neuron releases Ach
-Ach binds to nicotinic receptors on plasma membrane of muscle cell (sarcolemma)