Question 1

What is the power stroke?

Accepted Answer

A)  A protein found along the groove of the F-actin double helix 
B)  A T tubule and two adjacent terminal cisternae 
C)  The combination of myosin heads with active sites on actin molecules 
D)  The movement of myosin head while attached to actin myofilament 
E)  After exercise, the O2 taken in that exceeds the O2 required for resting metabolism 
A)  A protein found along the groove of the F-actin double helix 
B)  A T tubule and two adjacent terminal cisternae 
C)  The combination of myosin heads with active sites on actin molecules 
D)  The movement of myosin head while attached to actin myofilament 
E)  After exercise, the O2 taken in that exceeds the O2 required for resting metabolism

Question 2

What is the role of pacemaker cells?

Accepted Answer

A)  They rapidly develop action potentials. 
B)  They are shallow invaginations of the plasma membrane. 
C)  They maintain relatively constant tension for a period of time. 
D)  They are part of the intracellular cytoskeleton. 
E)  They are enzymes that remove phosphate from myosin. 
A)  They rapidly develop action potentials. 
B)  They are shallow invaginations of the plasma membrane. 
C)  They maintain relatively constant tension for a period of time. 
D)  They are part of the intracellular cytoskeleton. 
E)  They are enzymes that remove phosphate from myosin.

Question 3

Acetylcholine binds to a membrane bound receptor and causes ligand-gated sodium channels to open and results in

Accepted Answer

A)  hyperpolarization. 
B)  depolarization. 
C)  hypoplarization. 
D)  no change in membrane potential. 
E)  There is not enough information to predict the outcome. 
A)  hyperpolarization. 
B)  depolarization. 
C)  hypoplarization. 
D)  no change in membrane potential. 
E)  There is not enough information to predict the outcome.

Question 4

Due to the pattern of innervation of skeletal muscle, one would expect that

Accepted Answer

A)  there are fewer motor neurons than skeletal muscle fibers. 
B)  there are fewer muscle fibers than motor neurons. 
C)  the number of muscle fibers and motor neurons is equal. 
A)  there are fewer motor neurons than skeletal muscle fibers. 
B)  there are fewer muscle fibers than motor neurons. 
C)  the number of muscle fibers and motor neurons is equal.

Question 5

Troponin

Accepted Answer

A)  has two subunits. 
B)  is part of the myosin myofilament. 
C)  is a long, flexible protein. 
D)  has a calcium-binding site. 
E)  binds to ATP. 
A)  has two subunits. 
B)  is part of the myosin myofilament. 
C)  is a long, flexible protein. 
D)  has a calcium-binding site. 
E)  binds to ATP.

Question 6

The capacity of a muscle cell to shorten forcefully is known as

Accepted Answer

A)  contractility. 
B)  excitability. 
C)  extensibility. 
D)  elasticity. 
E)  flexibility. 
A)  contractility. 
B)  excitability. 
C)  extensibility. 
D)  elasticity. 
E)  flexibility.

Question 7

Too much acetylcholinesterase causes

Accepted Answer

A)  continuous stimulation of the muscle fiber. 
B)  rapid degradation of acetylcholine. 
C)  voltage-gated Ca2+ channels opening in the presynaptic terminal. 
D)  an increase in Na+ uptake by the muscle fiber. 
E)  exocytosis of synaptic vesicles. 
A)  continuous stimulation of the muscle fiber. 
B)  rapid degradation of acetylcholine. 
C)  voltage-gated Ca2+ channels opening in the presynaptic terminal. 
D)  an increase in Na+ uptake by the muscle fiber. 
E)  exocytosis of synaptic vesicles.

Question 8

Callie is a world class marathon runner. Which of the descriptions about her dominant type of skeletal muscle is FALSE?

Accepted Answer

A)  They split ATP slowly. 
B)  They have large deposits of myoglobin. 
C)  They are well adapted to anaerobic activity. 
D)  They have a well-developed blood supply. 
E)  They have low glycogen stores. 
A)  They split ATP slowly. 
B)  They have large deposits of myoglobin. 
C)  They are well adapted to anaerobic activity. 
D)  They have a well-developed blood supply. 
E)  They have low glycogen stores.

Question 9

Tetanus of a muscle is thought to be caused by

Accepted Answer

A)  high Ca2+ concentrations in the sarcoplasm. 
B)  the rapid movement of Na+ back into the sarcoplasmic reticulum. 
C)  an increase in stimulus strength. 
D)  increased temperature in the active muscle. 
E)  decreased amounts of Ca2+ in muscle tissue. 
A)  high Ca2+ concentrations in the sarcoplasm. 
B)  the rapid movement of Na+ back into the sarcoplasmic reticulum. 
C)  an increase in stimulus strength. 
D)  increased temperature in the active muscle. 
E)  decreased amounts of Ca2+ in muscle tissue.

Question 10

Calcium ion blocking agents would most likely affect

Accepted Answer

A)  action potential propogation along the transverse tubules. 
B)  release of Ca2+ from the sarcoplasmic reticulum. 
C)  movement of the tropomyosin molecule. 
D)  release of the myosin head from the G actin molecule. 
A)  action potential propogation along the transverse tubules. 
B)  release of Ca2+ from the sarcoplasmic reticulum. 
C)  movement of the tropomyosin molecule. 
D)  release of the myosin head from the G actin molecule.

Question 11

Which type of muscle tissue has spindle-shaped cells?

Accepted Answer

A)  Skeletal muscle 
B)  Smooth muscle 
C)  Cardiac muscle 
D)  Both skeletal and cardiac muscle are correct. 
E)  Both cardiac and smooth muscle are correct. 
A)  Skeletal muscle 
B)  Smooth muscle 
C)  Cardiac muscle 
D)  Both skeletal and cardiac muscle are correct. 
E)  Both cardiac and smooth muscle are correct.

Question 12

-What does "B" represent on the diagram?

Accepted Answer

A)  Threshold 
B)  Depolarization 
C)  Depolarization phase of action potential 
D)  Repolarization phase of action potential 
A)  Threshold 
B)  Depolarization 
C)  Depolarization phase of action potential 
D)  Repolarization phase of action potential

Question 13

The sarcolemma is the

Accepted Answer

A)  plasma membrane of a muscle fiber. 
B)  cytoplasm of a muscle fiber. 
C)  structural and functional unit of the skeletal muscle fiber. 
D)  contractile thread that extends the length of the muscle fiber. 
E)  protein strand composed of actin. 
A)  plasma membrane of a muscle fiber. 
B)  cytoplasm of a muscle fiber. 
C)  structural and functional unit of the skeletal muscle fiber. 
D)  contractile thread that extends the length of the muscle fiber. 
E)  protein strand composed of actin.

Question 14

Which of the following would be caused by a contraction of smooth muscle?

Accepted Answer

A)  Goose bumps 
B)  Blood leaving the left ventricle of the heart 
C)  Elevating the eyebrows 
D)  Blinking the eyelids 
E)  Deep inspiration 
A)  Goose bumps 
B)  Blood leaving the left ventricle of the heart 
C)  Elevating the eyebrows 
D)  Blinking the eyelids 
E)  Deep inspiration

Question 15

A fascicle

Accepted Answer

A)  is a bundle of reticular fibers. 
B)  is surrounded by perimysium. 
C)  is only found in smooth muscle. 
D)  possesses an external lamina. 
E)  is a bundle of collagen fibers. 
A)  is a bundle of reticular fibers. 
B)  is surrounded by perimysium. 
C)  is only found in smooth muscle. 
D)  possesses an external lamina. 
E)  is a bundle of collagen fibers.

Question 16

Which type of respiration rapidly produces ATP for short time periods?

Accepted Answer

A)  Anaerobic respiration 
B)  Aerobic respiration 
C)  Both anaerobic respiration and aerobic respiration are correct. 
A)  Anaerobic respiration 
B)  Aerobic respiration 
C)  Both anaerobic respiration and aerobic respiration are correct.

Question 17

Multiunit smooth muscle is located in the

Accepted Answer

A)  gastrocnemius. 
B)  wall of the GI tract. 
C)  wall of blood vessels. 
D)  wall of the heart. 
E)  reproductive system. 
A)  gastrocnemius. 
B)  wall of the GI tract. 
C)  wall of blood vessels. 
D)  wall of the heart. 
E)  reproductive system.

Question 18

Functionally, smooth muscle

Accepted Answer

A)  is well adapted to anaerobic metabolism. 
B)  exhibits autorhythmic contractions. 
C)  contracts in response to slow increases in length. 
D)  is unable to maintain tone. 
E)  rapidly develops an oxygen deficit. 
A)  is well adapted to anaerobic metabolism. 
B)  exhibits autorhythmic contractions. 
C)  contracts in response to slow increases in length. 
D)  is unable to maintain tone. 
E)  rapidly develops an oxygen deficit.

Question 19

One cause of spastic paralysis might be

Accepted Answer

A)  inhibition of acetylcholine molecules. 
B)  blockage of acetylcholine receptors. 
C)  inhibition of acetylcholinesterase. 
D)  destruction of synaptic vesicles. 
E)  increase in the amount of acetylcholinesterase. 
A)  inhibition of acetylcholine molecules. 
B)  blockage of acetylcholine receptors. 
C)  inhibition of acetylcholinesterase. 
D)  destruction of synaptic vesicles. 
E)  increase in the amount of acetylcholinesterase.

Question 20

Movements of the body are usually smooth and occur at differing rates because

Accepted Answer

A)  they are a mixture of isotonic and isometric contractions. 
B)  motor units contract out of phase at their own particular rates. 
C)  most muscle contractions closely resemble individual muscle twitches. 
D)  muscles of different sizes contract at different rates. 
E)  of the all-or-none principle. 
A)  they are a mixture of isotonic and isometric contractions. 
B)  motor units contract out of phase at their own particular rates. 
C)  most muscle contractions closely resemble individual muscle twitches. 
D)  muscles of different sizes contract at different rates. 
E)  of the all-or-none principle.

Exam 9: Muscular System: Histology and Physiology

What is the power stroke?

What is the role of pacemaker cells?

Acetylcholine binds to a membrane bound receptor and causes ligand-gated sodium channels to open and results in

Due to the pattern of innervation of skeletal muscle, one would expect that

Troponin

The capacity of a muscle cell to shorten forcefully is known as

Too much acetylcholinesterase causes

Callie is a world class marathon runner. Which of the descriptions about her dominant type of skeletal muscle is FALSE?

Tetanus of a muscle is thought to be caused by

Calcium ion blocking agents would most likely affect

Which type of muscle tissue has spindle-shaped cells?

-What does "B" represent on the diagram?

The sarcolemma is the

Which of the following would be caused by a contraction of smooth muscle?

A fascicle

Which type of respiration rapidly produces ATP for short time periods?

Multiunit smooth muscle is located in the

Functionally, smooth muscle

One cause of spastic paralysis might be

Movements of the body are usually smooth and occur at differing rates because

The Human Organism

The Chemical Basis of Life

Cell Biology

Tissues

Integumentary System

Skeletal System: Bones and Bone Tissue

Skeletal System: Gross Anatomy

Joint and Movement

Muscular System: Gross Anatomy

Functional Organization of Nervous Tissue

Spinal Cord and Spinal Nerves

Brain and Cranial Nerves

Integration of Nervous System Functions

The Special Senses

Autonomic Nervous System

Functional Organization of the Endocrine System

Endocrine Glands

Cardiovascular System: Blood

Cardiovascular System: the Heart

Cardiovascular System: Blood Vessels and Circulation

Lymphatic System and Immunity

Respiratory System

Digestive System

Nutrition, Metabolism, and Temperature Regulation

Urinary System

Water, Electrolyte, and Acid-Base Balance

Reproductive System

Development, Growth, Aging, and Genetics

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