Types of muscles

Question 1

Contain intercalated discs
Found only in the heart
Are striated
Under involuntary control

Answer 1

Cardiac muscle

Question 2

Under involuntary control.
Are not striated.
Found in stomach, gastrointestinal tract and blood vessels.

Answer 2

Smooth muscle

Question 3

> 600 of these muscles in the body
Under voluntary control
Are striated

Answer 3

Skeletal muscle

Question 4

A player is competing in a golf tournament. While hitting the ball, the player feels a sharp pain in a posterior muscle in their lower right leg.

Question: Which type of muscle did the player likely injure?

Answer 4

Skeletal

Question 5

A player is competing in a golf tournament. While hitting the ball, the player feels a sharp pain in a posterior muscle in their lower right leg.

Question: Which of these muscles did the player likely injure?

Answer 5

Gastrocnemius

Question 6

Description: A player is competing in a golf tournament. Before hitting the ball, the player takes a deep breath.

Question: Which muscle did the player NOT use in breathing?

a.
Internal intercostals

b.
Sternocleidomastoid

c.
External intercostals

d.
Diaphragm

Answer 6

b.
Sternocleidomastoid

Question 7

Description: A player is competing in a golf tournament. After hitting the ball, the player suddenly feels a sharp pain in his abdomen. Wincing, the player sits on the ground.

Question: Which of the following muscles would contract to pull the player to a sitting position?
a.
Masseter

b.
Temporalis

c.
Rectus abdominis

d.
Splenius capitis

Answer 7

c.
Rectus abdominis

Question 8

Description: A player is competing in a golf tournament. After hitting the ball, the player suddenly feels a sharp pain in his abdomen. Wincing, the player sits on the ground.

Question: Which muscle did the player use when wincing and closing their eyes?

a.
External oblique

b.
Gastrocnemius

c.
Orbicularis oculi

d.
Pectoralis

Answer 8

c.
Orbicularis oculi

Question 9

What are the two types of single muscle tissue?

Answer 9

Single unit (visceral) smooth muscle.

Multi-unit smooth muscle.

Question 10

What are the 3 characteristics of skeletal muscle cells?

Answer 10

Excitability
Contractility
Extensibility

Question 11

What is excitability?

Answer 11

Muscle cells that are stimulated via electrical signal.

Question 12

What is contractility?

Answer 12

Muscles cells that contract, or shorten and produce body movement.

Question 13

What is extensibility?

Answer 13

Muscles cells that have the ability to extend or stretch allowing muscles to return to their resting length.

Question 14

What are T Tubulars?

Answer 14

Transverse tubules that run across the long axis of the muscle fiber. These continually pump Ca2+ (calcium) inward from the sarcoplasm and are transportation for electrical impulses to travel deeper into the sarcolemma.

Question 15

What is sarcoplasm?

Answer 15

Similar to cytoplasm it is the fluid component in the cell directly under the sarcolemma.

Question 16

What is a sarcomere?

Answer 16

It is the basic unit for muscle contraction composed of thick and thin filaments.

Question 17

What are myofibrils?

Answer 17

Numerous fine fibers packed together in a sarcomere.

Question 18

What is striated muscle?

Answer 18

Dark stripes called A bands; light H bands run across the mid-section of each dark A band.

Light stripes called I bands; dark Z disc extends across the center of each light I band.

Question 19

What is a triad?

Answer 19

Triplet of tubules.

Question 20

What are myofilaments?

Answer 20

Every myofibril contains thousands of thick and thin myofilaments used for contraction.

Question 21

What are the 4 different protein molecules that make up myofilaments?

Answer 21

Actin.
Myosin.
Tropomysin.
Troponin.

Question 22

What is myosin?

Answer 22

Makes up nearly all of the thick filaments.

Myosin heads are called cross bridges when attached to actin.

Question 23

What is actin?

Answer 23

Globular protein that forms two fibrous strands twisted around each other to form the bulk of the thin filament.

Question 24

What is tropomyosin?

Answer 24

Protein that blocks the active sites on actin molecules.

Question 25

What is troponin?

Answer 25

Protein that holds tropomyosin molecules in place.

Question 26

What is a neuromuscular junction?

Answer 26

It is where motor neurons meet with the sarcolemma at the motor end plate. Acetylcholine (ACh) is released into the synaptic cleft that diffuses the gap stimulating receptors and initiates impulses in the sarcolemma.

Question 27

What are the 4 steps to sliding filament model of contraction theory?

Answer 27

Myosin heads bind to exposed active sites on actin.

Myosin heads bend and pull the thin filaments past them.

Then each head releases and then binds to the next active site and pulls again.

The entire myofibril shortens.

Question 28

What are the two types of muscle contraction?

Answer 28

Isotonic and isometric

Question 29

What is isotonic contraction?

Answer 29

When muscle length changes the tone or tension remains the same.

Question 30

What is isometric contraction?

Answer 30

When muscle tension or tone changes the length of the muscle stays the same.