Question 1

The chief function of the T-tubules is to:

Accepted Answer

A) provide nutrients to the muscle fiber. 
B) allow for the fiber to contract. 
C) allow for electrical signals to move deeper into the cell. 
D) allow for the generation of new muscle fibers. 
A) provide nutrients to the muscle fiber. 
B) allow for the fiber to contract. 
C) allow for electrical signals to move deeper into the cell. 
D) allow for the generation of new muscle fibers.

Question 2

Maintaining muscle tone is one of the few examples of a positive-feedback mechanism in the body.

Accepted Answer

A) True 
 B)False

Question 3

A motor neuron plus the muscle fibers to which it attaches is called a motor unit.

Accepted Answer

A) True 
 B)False

Question 4

The H-zone in a relaxed sarcomere is composed of only myosin.

Accepted Answer

A) True 
 B)False

Question 5

Match each term with its corresponding description regarding the sliding-filament theory.
-Protein that has active sites for cross-bridge heads

Accepted Answer

A) Troponin 
B) Myosin 
C) Actin 
D) T-tubules 
E) ATP
F)Calcium
G)Cross-bridges
H)Tropomyosin
I)Acetylcholine 
A) Troponin 
B) Myosin 
C) Actin 
D) T-tubules 
E) ATP
F)Calcium
G)Cross-bridges
H)Tropomyosin
I)Acetylcholine

Question 6

The myofilament that can be described as a globular protein strung together like beads to form two intertwined strands is:

Accepted Answer

A) troponin. 
B) actin. 
C) myosin. 
D) tropomyosin. 
A) troponin. 
B) actin. 
C) myosin. 
D) tropomyosin.

Question 7

Which part of the sarcomere stays almost the same size during contraction?

Accepted Answer

A) A-band 
B) I-band 
C) H-band 
D) None of the parts of the sarcomere stay the same size during contraction. 
A) A-band 
B) I-band 
C) H-band 
D) None of the parts of the sarcomere stay the same size during contraction.

Question 8

The release of calcium by the sarcoplasmic reticulum begins the contraction phase of a twitch contraction.

Accepted Answer

A) True 
 B)False

Question 9

Based on your knowledge of the structure and function of the muscle cells, explain why you would expect to find multiple mitochondria and nuclei in them under microscopic examination.

Accepted Answer

Muscle cells, also known as muscle fiber

Question 10

When a muscle contracts, the muscle always becomes shorter.

Accepted Answer

A) True 
 B)False

Question 11

Anaerobic respiration is the first choice of the muscle cell for the production of ATP.

Accepted Answer

A) True 
 B)False

Question 12

Match each term with its corresponding description regarding the sliding-filament theory.
-By energizing these structures, chemical energy is converted to mechanical energy

Accepted Answer

A) Troponin 
B) Myosin 
C) Actin 
D) T-tubules 
E) ATP
F)Calcium
G)Cross-bridges
H)Tropomyosin
I)Acetylcholine 
A) Troponin 
B) Myosin 
C) Actin 
D) T-tubules 
E) ATP
F)Calcium
G)Cross-bridges
H)Tropomyosin
I)Acetylcholine

Question 13

All of the following are characteristics of smooth muscle except:

Accepted Answer

A) there are no striations. 
B) there are no T-tubules. 
C) thin and thick filaments are aligned in sarcomeres like skeletal muscles. 
D) the sarcoplasmic reticula are loosely organized. 
A) there are no striations. 
B) there are no T-tubules. 
C) thin and thick filaments are aligned in sarcomeres like skeletal muscles. 
D) the sarcoplasmic reticula are loosely organized.

Question 14

The cell membrane of a muscle fiber is called the sarcoplasmic reticulum.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following terms describes an isometric contraction?

Accepted Answer

A) Eccentric contraction 
B) Static tension 
C) Concentric contraction 
D) Both A and C 
A) Eccentric contraction 
B) Static tension 
C) Concentric contraction 
D) Both A and C

Question 16

During an isotonic contraction, the tension produced by the myosin cross-bridges cannot overcome the load placed on the muscle.

Accepted Answer

A) True 
 B)False

Question 17

Which of the following statements about cardiac muscle is incorrect?

Accepted Answer

A) Cardiac muscle requires nervous stimulation to contract. 
B) Cardiac muscle is also called striated involuntary muscle. 
C) Cardiac muscle contains intercalated disks. 
D) All of the above statements are correct. 
A) Cardiac muscle requires nervous stimulation to contract. 
B) Cardiac muscle is also called striated involuntary muscle. 
C) Cardiac muscle contains intercalated disks. 
D) All of the above statements are correct.

Question 18

Aerobic respiration:

Accepted Answer

A) allows the body to avoid the use of oxygen for a short time. 
B) results in the formation of an incompletely catabolized molecule. 
C) results in the formation of lactate. 
D) produces the maximum amount of energy available from each glucose molecule. 
A) allows the body to avoid the use of oxygen for a short time. 
B) results in the formation of an incompletely catabolized molecule. 
C) results in the formation of lactate. 
D) produces the maximum amount of energy available from each glucose molecule.

Question 19

During the latent period of muscle contraction, the impulse is transmitted from the sarcolemma to the sarcomere.

Accepted Answer

A) True 
 B)False

Question 20

Define rigor mortis. Why does it occur?

Accepted Answer

Rigor mortis is a postmortem condition c

Exam 17: Muscle Contraction

The chief function of the T-tubules is to:

Maintaining muscle tone is one of the few examples of a positive-feedback mechanism in the body.

A motor neuron plus the muscle fibers to which it attaches is called a motor unit.

The H-zone in a relaxed sarcomere is composed of only myosin.

Match each term with its corresponding description regarding the sliding-filament theory. -Protein that has active sites for cross-bridge heads

The myofilament that can be described as a globular protein strung together like beads to form two intertwined strands is:

Which part of the sarcomere stays almost the same size during contraction?

The release of calcium by the sarcoplasmic reticulum begins the contraction phase of a twitch contraction.

Based on your knowledge of the structure and function of the muscle cells, explain why you would expect to find multiple mitochondria and nuclei in them under microscopic examination.

When a muscle contracts, the muscle always becomes shorter.

Anaerobic respiration is the first choice of the muscle cell for the production of ATP.

Match each term with its corresponding description regarding the sliding-filament theory. -By energizing these structures, chemical energy is converted to mechanical energy

All of the following are characteristics of smooth muscle except:

The cell membrane of a muscle fiber is called the sarcoplasmic reticulum.

Which of the following terms describes an isometric contraction?

During an isotonic contraction, the tension produced by the myosin cross-bridges cannot overcome the load placed on the muscle.

Which of the following statements about cardiac muscle is incorrect?

Aerobic respiration:

During the latent period of muscle contraction, the impulse is transmitted from the sarcolemma to the sarcomere.

Define rigor mortis. Why does it occur?

Organization of the Body

Homeostasis

Chemistry of Life

Biomolecules

Cell Structure

Cell Function

Cell Growth and Development

Introduction to Tissues

Tissue Types

Skin

Skeletal Tissues

Axial Skeleton

Appendicular Skeleton

Articulations

Axial Muscles

Appendicular Muscles

Nervous System Cells

Nerve Signaling

Central Nervous System

Peripheral Nervous System

Autonomic Nervous System

General Senses

Special Senses

Endocrine Regulation

Endocrine Glands

Blood

Heart

Blood Vessels

Circulation of the Blood

Lymphatic System

Innate Immunity

Adaptive Immunity

Stress

Respiratory Tract

Ventilation

Gas Exchange Transport

Upper Digestive Tract

Lower Digestive Tract

Digestion and Absorption

Nutrition and Metabolism

Urinary System

Fluid and Electrolyte Balance

Acid-Base Balance

Male Reproductive System

Female Reproductive System

Growth, Development, and Aging

Genetics and Heredity

Filters