Exam 3 Study Guide

Question 1

What period is a muscle in when it is temporarily not able to respond to a stimulus?

Answer 1

Refractory Period

Question 2

What is a Fasciculus ?

Answer 2

A bundle of skeletal muscle cells surrounded by a membrane called a Perimysium.

Question 3

What type of proteins are actin and myosin?

Answer 3

Contractile Proteins.

Question 4

What characteristic distinguishes or sets apart muscle tissue?

Answer 4

Muscle tissue has the special ability to contract or shorten.

Question 5

What structure stores calcium in skeletal muscle cells?

Answer 5

Sarcoplasmic Reticulum

Question 6

What would you expect to see when a sarcomere contracts and thin filaments move over thick filaments ?

Answer 6

The contact between the thin and thick filaments increases

Question 7

What are the functions of muscle?

Answer 7

contract to produce movement, sustain body posture and position, maintain body temperature, store nutrients, and stabilize joint

Question 8

How does muscle tissue remain active and healthy ?

Answer 8

Proper diet, daily use, exercise. Weight training

Question 9

What is a cross bridge?

Answer 9

A cross bridge is the globular head of a myosin molecule that attaches to an actin filament in a muscle cell

Question 10

What is the fibrous connective tissue surrounding the fascicles?

Answer 10

The connective tissue sheath covering each fasciculus is known as perimysium

Question 11

What determines the power of a muscle?

Answer 11

Muscle Size
Muscle Fiber Type
Motor Unit Recruitment
Movement Speed
Type of Muscle Action

Question 12

What propagates the action potential down the muscle fibers?

Answer 12

T-Tubules

Question 13

What is the name of the plasma membrane of a muscle fiber?

Answer 13

Sarcolemma

Question 14

Where are the Acetylcholine receptors in the Sarcolemma? What part?

Answer 14

Acetylcholine receptors are primarily located on the motor end plate of the sarcolemma

Question 15

Where does the energy for muscle contraction come from?

Answer 15

ATP

Question 16

What type of protein would troponin and tropomyosin be classified as?

Answer 16

regulatory proteins that control muscle contraction and relaxation

Question 17

What is another name for a muscle fiber?

Answer 17

myofiber

Question 18

What cell part would you expect to find a lot of in muscle cells?

Answer 18

large mitochondria

Question 19

What is Myoglobin?

Answer 19

Myoglobin is a protein found in the heart and skeletal muscles that stores and delivers oxygen to muscle cells

Question 20

What starts a skeletal muscle contraction?

Answer 20

the neuromuscular junction

Question 21

What is the definition of a twitch?

Answer 21

a brief spasmodic contraction of the muscle fibers

Question 22

What is the name of the condition in which hardening of the muscle fibers, caused by calcification occurs?

Answer 22

myositis ossificans

Question 23

Where does a sarcomere begin and end?

Answer 23

The Z-line, or Z-disc, marks the beginning and end of a sarcomere

Question 24

Why does rigor mortis happen?

Answer 24

necessary for the breakdown of actin-myosin filaments in the muscle fibers

Question 25

What are T-tubules and what do they transect or cut across?

Answer 25

transmitting the action potential from the sarcolemma to the sarcoplasmic reticulum

Question 26

What is the name of the functional unit of skeletal muscle?

Answer 26

The sarcomere is the functional unit of skeletal muscle, essential for proper contraction