Chapter 12 - Muscle Physiology

Question 1

Muscles are connected to bones by _____.

Answer 1

tendons

Question 2

“meaty” part of muscle

Answer 2

body

Question 3

Calcium is stored in the _____.

Answer 3

sarcoplasmic reticulum

Question 4

a muscle fiber’s semifluid cytoplasm

Answer 4

sarcoplasm

Question 5

contains a muscle fiber’s contractile machinery

Answer 5

myofibril

Question 6

physically blocks myosin-binding sites while muscle is at rest

Answer 6

tropomyosin

Question 7

What are the regulatory proteins found in thin filaments?

Answer 7

1. tropomyosin

2. troponin

Question 8

During muscle contraction, _____ and the _____ shorten.

Answer 8

I bands; H zone

Question 9

Steps to Crossbridge Cycle

Answer 9

1. Binding of myosin to actin
2. Power stroke
3. Rigor
4. Unbinding of myosin and actin
5. Cocking of the myosin head

Question 10

process of muscle contraction whereby thick and thin filaments slide past each other

Answer 10

sliding-filament mechanism

Question 11

the mechanism that drives muscle contraction

Answer 11

crossbridge cycle

Question 12

in a muscle cell, the sequence of events that links the action potential to the contraction

Answer 12

excitation-contraction coupling

Question 13

myosin in low-energy form

Answer 13

rigor