Chapter 9

Which of the following is true? A. Skeletal muscle is capable of spontaneous contraction. B. Smooth muscle is found in the walls of hollow organs. C. Cardiac muscle cells have multiple nuclei. D. Smooth muscle cells are very long and cylindrical. E. There is a small amount of smooth muscle in the heart.

Smooth muscle is found in the walls of hollow organs

The sarcolemma is the A. cell membrane of a muscle fiber. B. cytoplasm of muscle cells. C. structural and functional unit of the skeletal muscle cell. D. contractile thread that extends the length of the muscle fiber. E. protein strand composed of actin.

cell membrane of a muscle fiber

A condition in which stimuli occur so rapidly that there are no intervening relaxations between contractions is called A. complete tetanus. B. incomplete tetanus. C. involuntary paralysis. D. all or none tetanus. E. treppe.

complete tetanus

Synaptic vesicles in the neuromuscular junction contain A. calcium. B. ATP. C. acetylcholine. D. acetylcholinesterase. E. sodium.

acetylcholine

A stimulus either causes an action potential or it doesn't. This is called A. an all-or-none response. B. a graded response. C. a latent period response. D. a relative refractory response. E. an arbitrary response.

an all-or-none response

Smooth muscle and cardiac muscle are similar in that they both

are under involuntary control

T tubules A. provide nutrients to the muscle fiber. B. generate new muscle fibers. C. conduct action potentials deep into the muscle cell. D. release acetylcholine. E. store calcium ions.

conduct action potentials deep into the muscle cell

Muscle myofibrils A. are found in the sarcolemma. B. extend from the sarcolemma to the T-tubule. C. contain myosin and actin myofilaments. D. hold muscle cells together. E. do not appear striated.

contain myosin and actin myofilaments

Actin myofilaments A. resemble bundles of minute golf clubs. B. contain both myosin and tropomyosin. C. are held in place by the M line. D. contain strands of fibrous actin. E. are the thickest proteins in muscle.

contain strands of fibrous actin

What type of muscle tissue causes vasoconstriction?

cardiac muscle

Which type of muscle tissue causes contraction of the heart?

cardiac muscle

Which type of muscle tissue has cells that branch?

cardiac muscle

Skeletal muscle fibers

possess striations

A myofilament is the A. cell membrane of a muscle fiber. B. cytoplasm of muscle cells. C. structural and functional unit of the skeletal muscle cell. D. contractile thread that extends the length of the muscle fiber. E. protein strand composed of actin or myosin.

protein strand composed of actin or myosin

After contraction has occurred, the calcium is A. destroyed by cholinesterase. B. chemically bound to the cross bridges. C. secreted by the Golgi apparatus to the outside of the cell. D. released from troponin. E. returned to the sarcolemma.

released from troponin

Myosin phosphatase A. activates myosin kinase. B. forms the cross-bridge. C. removes phosphate from myosin. D. binds to calcium-calmodulin complex. E. opens calcium channels.

removes phosphate from myosin

Muscles exhibit the property of excitability. This means that the muscle

responds to stimulation by the nervous system

Body temperature A. is raised by sweating. B. results from the heat produced when muscles contract. C. will increase after blood vessels in the skin constrict. D. is lowered by shivering. E. decreases when the rate of the chemical reactions increase.

results from the heat produced when muscles contract

T tubules are invaginations of the A. sarcoplasmic reticulum. B. sarcomere. C. myofibril. D. sarcoplasm. E. sarcolemma.

sarcolemma

Hypertrophy of skeletal muscles from weight lifting is caused by an increase in the

size of muscle fibers

Which type of muscle tissue is multinucleated?

skeletal muscle

Which type of muscle tissue would cause flexion and extension of the arm?

skeletal muscle

The model that describes the contraction of the muscle is called the A. contraction cycle. B. power stroke. C. sliding filament model. D. slipping fibril mechanism. E. paddle model.

sliding filament model

What type of muscle tissue causes peristalsis?

smooth muscle

Which type of muscle tissue has spindle-shaped cells?

smooth muscle

Depolarization of the cell membrane occurs when there is a rapid influx (inflow) of A. potassium ions. B. chloride ions. C. calcium ions. D. sodium ions. E. amino acids.

sodium ions

The sarcoplasmic reticulum A. stores calcium ions. B. shortens during muscle contraction. C. transmits nerve impulses to the myofibrils. D. connects adjacent sarcomeres. E. covers the muscle fiber.

stores calcium ions

The outside of the resting plasma membrane is __________ relative to the inside of the resting plasma membrane. A. positively charged B. negatively charged C. electrically neutral D. recharged E. None of these choices is correct.

positively charged

Which type of muscle tissue possesses striations?

both skeletal and cardiac muscle

The region of the sarcomere that contains both actin and myosin myofilaments is called the

A band

When comparing smooth and skeletal muscle cells, which of the following statements is true? A. Smooth muscle cells have striations. B. The myofilaments in smooth muscle do not form sarcomeres. C. Smooth muscle cells are larger than skeletal muscle cells. D. Smooth muscle has a lot of actin and myosin. E. Smooth muscle cells are multinucleated.

The myofilaments in smooth muscle do not form sarcomeres

What is a triad? 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 oxygen taken in that exceeds the oxygen required for resting metabolism

a T tubule and two adjacent terminal cisternae

An isometric contraction is described as A. action potential frequency is high enough that no relaxation of muscle fibers occurs. B. a muscle produces constant tension during contraction. C. a muscle produces an increasing tension as the length remains constant. D. a muscle produces increasing tension as it shortens. E. a muscle produces tension, but the length of the muscle is increasing.

a muscle produces an increasing tension as the length remains constant

An isotonic contraction is described as A. action potential frequency is high enough that no relaxation of muscle fibers occurs. B. a muscle produces constant tension during contraction. C. a muscle produces an increasing tension during contraction. D. a muscle produces increasing tension as it shortens. E. a muscle produces tension, but the length of the muscle is increasing.

a muscle produces constant tension during contraction

A concentric contraction is described as A. action potential frequency is high enough that no relaxation of muscle fibers occurs. B. a muscle produces constant tension during contraction. C. a muscle produces an increasing tension during contraction. D. a muscle produces increasing tension as it shortens. E. a muscle produces tension, but the length of the muscle is increasing.

a muscle produces increasing tension as it shortens

An eccentric contraction is described as A. action potential frequency is high enough that no relaxation of muscle fibers occurs. B. a muscle produces constant tension during contraction. C. a muscle produces an increasing tension during contraction. D. a muscle produces increasing tension as it shortens. E. a muscle produces tension, but the length of the muscle is increasing.

a muscle produces tension, but the length of the muscle is increasing

What is tropomyosin? 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 oxygen taken in that exceeds the oxygen required for resting metabolism

a protein found along the groove of the F-actin double helix

Lack of acetylcholinesterase in the synaptic cleft would result in A. a decrease in acetylcholine production by the motor neuron. B. continuous stimulation of the postsynaptic membrane. C. rapid degradation of acetylcholine. D. relaxation of the muscle. E. continuous stimulation of the presynaptic membrane.

continuous stimulation of the postsynaptic membrane

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

contractile thread that extends the length of the muscle fiber

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

contractility

Sarcoplasm is the A. cell membrane of a muscle fiber. B. cytoplasm of muscle cells. C. structural and functional unit of the skeletal muscle cell. D. contractile thread that extends the length of the muscle fiber. E. protein strand composed of actin or myosin.

cytoplasm of muscle cells

Which of the following would contribute to muscular fatigue in the muscle fiber? A. the emotional state of an individual B. depletion of ATP reserves C. inability of the motor neuron to produce sufficient quantities of acetylcholine D. depletion of neurotransmitter E. blocked receptors in the postsynaptic membrane

depletion of ATP reserves

Acetylcholine binds to a membrane bound receptor and causes ligand-gated sodium channels to open and results in A. hyperpolarization. B. depolarization. C. hypoplarization. D. no change in membrane potential. E. There is not enough information to predict the outcome.

depolarization

Which of the following connective tissue layers is outside all the others? A. perimysium B. endomysium C. epimysium D. paramysium E. sarcolemma

epimysium

Acetylcholine is released from the presynaptic terminal by the process of A. exocytosis. B. diffusion. C. phagocytosis. D. active transport. E. endocytosis.

exocytosis

Which of the following is part of a thin myofilament? A. ATP-binding site B. globular (G) actin C. calcium D. myosin E. sarcolemma

globular (G) actin

Cardiac muscle cells are like skeletal muscle cells in that they both A. have striations. B. depolarize as a result of sodium and calcium influxes. C. possess intercalated disks. D. lack sarcomeres. E. are multinucleated.

have striations

Shivering A. increases heat loss from the skin. B. is a response of the nervous system to a high fever. C. helps raise body temperature. D. causes vasoconstriction. E. occurs when body temperature is slightly elevated.

helps raise body temperature

Troponin 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.

is a long, flexible protein

A fasciculus 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.

is surrounded by perimysium

A waste product of anaerobic respiration in muscle cells is A. uric acid. B. hydrochloric acid. C. lactic acid. D. carbonic acid. E. pyruvic acid.

lactic acid

The time between application of the stimulus to a motor neuron and the beginning of contraction is called the _____ phase. A. contraction B. relaxation C. latent or lag D. refractory E. threshold

latent or lag

The length of the resting sarcomere is A. longer than the length of a contracted sarcomere. B. shorter than the length of a contracted sarcomere. C. the same length as a contracted sarcomere. D. the same length as the muscle fiber. E. the same length as the myofibril.

longer than the length of a contracted sarcomere

Which of the following actions is caused by contraction of skeletal muscle? A. contraction of the heart B. moving your feet in walking C. movement of food through the digestive tract D. emptying of the urinary bladder E. vasoconstriction

moving your feet in walking

Skeletal muscle develops from multinucleated cells called

myoblasts

The active sites to which cross-bridges attach are found on the A. sarcoplasmic reticulum. B. actin myofilaments. C. Z disks. D. T tubules. E. myosin myofilaments.

myosin myofilaments

Which of the following is mismatched? A. I band - contains only actin B. M line - middle of the H zone C. Z disk - structure between adjacent sarcomeres D. myosin myofilaments - thin myofilaments E. actin myofilaments - thin myofilaments

myosin myofilaments - thin myofilaments

Which of the following structures contains the other four items listed? A. postsynaptic membrane B. presynaptic terminal C. synaptic cleft D. neuromuscular junction E. receptors on postsynaptic membrane

neuromuscular junction

The sites where a chemical substance is transmitted from the presynaptic terminal of an axon to the postsynaptic membrane of a muscle fiber are called A. neuromuscular junctions. B. sarcomeres. C. myofilaments. D. Z disks. E. cell body of neuron.

neuromuscular junctions

Visceral smooth muscle A. may contain groups of cells that function as an independent unit. B. occurs in sheets and exhibits numerous gap junctions. C. contracts only when stimulated. D. does not function as a unit. E. All of these choices are correct.

occurs in sheets and exhibits numerous gap junctions

An action potential A. occurs when the local potential reaches threshold level. B. is not propagated. C. has no repolarization phase. D. is an example of negative feedback. E. can be of varying strengths depending on strength of the stimulus.

occurs when the local potential reaches threshold level

A sarcomere extends from

one Z disk to an adjacent Z disk

When repolarization of the cell membrane is complete, the A. cell dies. B. cell regenerates. C. cell no longer has a potential difference across its membrane. D. cell is no longer responsive. E. original polarity of the cell is restored.

original polarity of the cell is restored

A sarcomere is the A. cell membrane of a muscle fiber. B. cytoplasm of muscle cells. C. structural and functional unit of the skeletal muscle cell. D. contractile thread that extends the length of the muscle fiber. E. protein strand composed of actin or myosin.

structural and functional unit of the skeletal muscle cell

Endomysium is a delicate network of loose connective tissue that A. surrounds each muscle fiber. B. forms a sheath around a fasciculus. C. is composed of elastic fibers. D. separates individual muscles. E. penetrates muscle fibers.

surrounds each muscle fiber

In order for muscle relaxation to occur, A. calcium ions must be transported to troponin. B. power strokes slow down. C. the active sites on actin must be blocked. D. sodium ions must be actively transported to troponin. E. the active sites on myosin must be uncovered.

the active sites on actin must be blocked

The type of muscle fatigue known as "psychological fatigue" is the result of A. depleted ATP reserves. B. increased calcium ion concentration in the sarcoplasm. C. decreased levels of acetylcholine. D. the emotional state of an individual. E. None of these choices is correct.

the emotional state of an individual

Myosin is also known as the A. thick myofilament. B. thin myofilament. C. intermediate myofilament. D. short myofilament. E. sarcomere.

thick myofilament

Which of the following is composed of myosin molecules? A. thick myofilaments B. I Bands C. Z disks D. sarcolemma E. tropomyosin

thick myofilaments

A muscle fiber will respond to a stimulus when that stimulus reaches the _____ level. A. threshold B. relaxation C. rigor mortis D. recruitment E. resting

threshold

Which of the following would occur as a result of a single muscle fiber contraction? A. tetanus B. tone C. treppe D. twitch E. paralysis

twitch

Channels that open or close in response to changes in the electrical charge or voltage across the plasma membrane are called A. ligand-gated ion channels. B. non-gated ion channels. C. relegated ion channels. D. voltage-gated ion channels. E. obligated ion channels.

voltage-gated ion channels