C9: muscle tissue

Which of the following is the type of muscle that pushes blood through the blood vessels of the cardiovascular system?

A. cardiac muscle
B. smooth muscle
C. skeletal muscle
D. appendicular muscle
E. None of the answers are correct.

A

Smooth muscles are primarily used to ________.

A. push fluid and solids along the digestive tract
B. pump blood through the circulation
C. provide voluntary movements to the body
D. generate heat
E. pull on bones of the skeleton

A

Which of the following is a function of skeletal muscle?

A. support soft tissues
B. produce skeletal movement
C. maintain body temperature
D. maintain posture
E. All of the answers are correct.

E

Which unique quality of muscle tissue is defined as the ability to continue to contract over a range of resting lengths?

A. elasticity
B. contractility
C. extensibility
D. excitability

C

A yoga enthusiast is able to maintain an inversion position, in which the person suspends the body weight on the hands while the feet are tucked up into the chest. Which of the following functions of muscle tissue does this describe?

A. the maintenance of body temperature
B. maintenance of posture or body position
C. the support of soft tissues
D. the regulation of materials entering and exiting the body

B

Which place in the body would you be unlikely to find skeletal muscle?

A. bladder
B. lower back
C. facial area
D. finger

A

Why are skeletal muscles called voluntary?

A. Their contractions can be consciously controlled.
B. Contraction of specific muscles occurs to maintain body posture and body position.
C. These muscles maintain a constant rhythm of contraction.
D. Only these muscles are stimulated to contract by the central nervous system.
E. All of the answers are correct.

A

The layers of connective tissue surrounding a skeletal muscle from the inside to the outside in correct order are ________.

A. epimysium, endomysium, and perimysium
B. perimysium, epimysium, and endomysium
C. endomysium, epimysium, and perimysium
D. epimysium, perimysium, and endomysium
E. endomysium, perimysium, and epimysium

E

The epimysium, which separates the muscle from surrounding tissues and organs, is connected to the ________.

A. deep fascia
B. aponeuroses
C. superficial fascia
D. subserous fascia
E. None of the answers are correct.

A

The connective tissue surrounding a fascicle is called ________.

A. a tendon
B. epimysium
C. perimysium
D. endomysium
E. an aponeurosis

C

The attachment of a muscle to a bone is called ________.

A. a capsule
B. a bursa
C. a ligament
D. an aponeurosis
E. either a tendon or an aponeurosis

E

Which of these orders of functional muscle structures progresses from the smallest to largest in diameter?

A. muscle, fascicle, muscle fiber, myofibril
B. myofibril, muscle fiber, fascicle, muscle
C. fascicle, muscle fiber, myofibril, muscle
D. muscle, muscle fiber, myofibril, fascicle
E. fascicle, myofibril, muscle fiber, filament

B

Skeletal muscle fibers arise from embryonic cells called ________.

A. myomeres
B. myoblasts
C. myofilaments
D. myofibrils
E. myotomes

B

Why does a skeletal muscle fiber have more than one nucleus?

A. During development, groups of embryonic cells called myoblasts fuse together to form a single muscle fiber.
B. During muscular activity, parts of each muscle fiber break down, and the remaining parts, including their nuclei, fuse into new combination fibers.
C. During development, the sarcolemmae of newly formed muscle fibers disintegrate, making many muscle cells into one.
D. During development, the nucleus of each myoblast replicates several times.
E. All of the answers are correct.

A

The sarcoplasmic reticulum is (the) ________.

A. sarcolemma of skeletal muscle fibers
B. a membrane complex in skeletal muscles similar to rough endoplasmic reticulum
C. cytoplasm of skeletal muscle fibers
D. extension of the skeletal muscle sarcolemma into the cell
E. a membrane complex in skeletal muscles similar to smooth endoplasmic reticulum

E

The structures within the muscle fiber that shorten to cause skeletal muscle fiber contraction are (the) ________.

A. myoblasts
B. myosatellite cells
C. neuromuscular synapses
D. myoneural junctions
E. myofibrils

E

Delayed-onset muscle soreness is potentially caused by microscopic ruptures at the ________ of the sarcomeres.

A. Z line
B. M line
C. A band
D. I band
E. H band

A

A skeletal muscle is divided into a series of internal compartments, each of which contains a bundle of muscle fibers called a ________.

A. triad
B. sarcomere
C. myofibril
D. fascicle
E. cross-bridge

D

The connective tissue that surrounds each skeletal muscle fiber and binds each muscle fiber to its neighbor is the ________.

A. periosteum
B. endomysium
C. perimysium
D. epimysium
E. endosteum

B

The smallest functional units of the muscle fibers are the ________.

A. fascicles
B. myofilaments
C. cisternae
D. neuromuscular synapses
E. sarcomeres

E

The fusion of the epimysium, perimysium, and endomysium at the end of a muscle is called a __________.

A. sarcolemma
B. tendon
C. muscle fiber
D. ligament

B

The sarcoplasmic reticulum stores ________.

A. calcium ions
B. glycogen
C. oxygen
D. glucose
E. ATP

A

Which of the following ions is the trigger for a muscle contraction?

A. potassium
B. acetylcholine
C. sodium
D. calcium
E. chloride

D

The function of T tubules is to ________.

A. release acetylcholine into the synaptic cleft
B. bind muscle fibers together at the neuromuscular synapse
C. bind actin and myosin molecules together
D. help distribute the electrical impulse, which triggers the release of calcium ions by the sarcoplasmic reticulum
E. separate the terminal from the motor end plate of the skeletal muscle fiber

D

Troponin assists in controlling the interaction between myosin heads and thin filaments by ________.

A. assisting in the formation of the myofilaments
B. binding calcium ions to produce a change in the orientation of the troponin-tropomyosin complex
C. forming a long chain that covers the active sites of thin filaments
D. storing calcium ions in the troponin-tropomyosin complex
E. binding to myosin heads, which allows tropomyosin to pivot, thereby exposing the active sites

B

Which of the following molecules or ions are absent following death and leads to rigor mortis?

A. ATP
B. acetylcholine
C. acetylcholinesterase
D. calcium
E. None of these are correct.

A

The sliding mechanism of myofilaments works when ________.

A. the myosin heads of the thick filaments bind to active sites on the actin molecules of the thin filaments
B. calcium ions bind to active sites on the actin molecules of the thin filaments
C. the myosin heads pivot away from the M line toward the Z lines
D. the thick filaments detach from the muscle tendon
E. the troponin-tropomyosin complex interacts with the actin molecules

A

Each skeletal muscle fiber is controlled by a single ________.

A. neurotransmitter
B. motor end plate
C. triad of transverse tubule and terminal cisternae
D. motor neuron whose cell body is located inside the central nervous system
E. synaptic cleft

D

The motor neuron releases acetylcholine, which then binds to receptors sites on a special region of the sarcolemma called ________.

A. a T tubule
B. the sarcoplasmic reticulum
C. the motor unit
D. a motor end plate
E. a fascicle

D

The neurotransmitter involved in the process of contraction in skeletal muscles is ________.

A. globulin
B. serotonin
C. ATP
D. troponin
E. acetylcholine

E

Which of the following events occurs in a muscle that is relaxing?

A. Hydrolysis of ATP occurs.
B. Released calcium ions are present.
C. Myosin heads bind to active sites on the thin filaments.
D. The muscle fiber shortens.
E. AChE is present in the synaptic cleft.

E

What is the significance of the change in membrane potential of the T tubules within the sarcolemma?

A. It triggers the sarcoplasmic reticulum to release of calcium ions.
B. This change is caused by the release of actin and myosin molecules.
C. It has no role, because this phenomenon does not occur.
D. This change is caused by the displacement of actin and myosin molecules.
E. None of the answers are correct.

A

Which of the following events occurs first?

A. Calcium ions are released from the sarcoplasmic reticulum.
B. Myosin cross-bridges attach to actin.
C. The myosin head pivots toward the M line.
D. The myosin head binds ATP and detaches from actin.
E. Calcium binds to troponin.

A

Skeletal muscle fiber contractions are caused by the interaction between the ________ and the ________ filaments of the sarcomeres.

A. titin; thick
B. titin; thin
C. thick; nebulin
D. thin; thick
E. thin; nebulin

D

When muscles contract, the Z lines in a sarcomere __________.

A. overlap with the A band
B. move away from the A band
C. pull on the thin filaments
D. move toward the M line

D

Which part of the muscle cell contains the receptors capable of binding the neurotransmitter from the neuron?

A. myosin
B. motor end plate
C. T tubule
D. synaptic terminal

B

Put the following events in order of their occurrence during a contraction.

A. increase in calcium concentration, binding of myosin to actin, breaking of cross-bridges, exposure of active sites
B. breaking of cross-bridges, increase in calcium concentration, binding of myosin to actin, exposure of active sites
C. exposure of active sites, binding of myosin to actin, increase in calcium concentration, breaking of cross-bridges
D. increase in calcium concentration, exposure of active sites, binding of myosin to actin, breaking of cross-bridges

D

Which of the following is true of muscle contraction?

A. During a muscle contraction, the sarcoplasmic reticulum absorbs large amounts of calcium from the cytoplasm.
B. When muscle contraction ends, the sarcomere passively returns to its resting length.
C. Acetylcholine binds to the T tubule, triggering electrical impulse transmission into the muscle cell.
D. All of these statements are true.

B

When a muscle contracts, the overall muscle length __________.

A. shortens
B. lengthens
C. remains the same
D. does not perform any of the listed actions

A

The steady increase in muscular tension produced by increasing the number of active motor units is called ________.

A. muscle tone
B. recruitment
C. peak tension
D. muscle spindles
E. a muscle twitch

B

When one motor neuron fires a single action potential the result affects one ________.

A. upper motor neuron
B. motor unit
C. lower motor neuron
D. synaptic cleft
E. sensory unit

B

The number of cells per motor unit in the leg muscles can reach up to ________.

A. many thousands
B. millions
C. less than a dozen
D. one hundred
E. hundreds

A

When a single motor neuron controls a greater number of muscle fibers in a motor unit, ________.

A. the less precise the control will be
B. each contraction will last longer
C. the greater the number of stimuli will be required to produce a contraction
D. the muscle contraction will be slower
E. None of the answers are correct.

A

While wearing a cast due to a broken bone, muscles shrink due to the process of ________.

A. hypertrophy
B. atrophy
C. chronic inflammation, or swelling
D. recruitment
E. cell division

B

The contraction of a single muscle cell is called a __________.

A. muscle contraction
B. muscle twitch
C. peak tension
D. motor unit

B

In the case of the triceps brachii, the shoulder is the ________; the olecranon is the ________.

A. origin; insertion
B. insertion; origin
C. synergist; fixator
D. agonist; antagonist
E. None of the answers are correct.

A

Regarding a typical muscle insertion, which of the following is true?

A. If there are several tendons at one end of a muscle and just one at the other, there are multiple insertions.
B. The insertion is proximal to the origin.
C. The insertion moves more than does the origin.
D. If a muscle extends between a broad aponeurosis and a narrow tendon, the aponeurosis is the insertion.
E. All of the answers are correct.

C

The adductor magnus muscle is so named, partially due to the ________.

A. location of the muscle
B. parallel versus pennate arrangement of its fibers
C. orientation of its muscle fibers
D. size of the muscle
E. shape of the muscle

D

What does the term longissimus in a muscle name primarily indicate about that muscle?

A. the manner in which the fibers of the muscle are oriented
B. the action of the muscle
C. the insertion of the muscle fibers is oriented with respect to the long axis of the body
D. the muscle location in the body
E. the muscle length

E

Typically, the insertion of a muscle is ________ to its origin.

A. proximal
B. distal
C. deep
D. lateral
E. medial

B

A lever in which the load is between the fulcrum and the applied force is a ________.

A. second-class lever
B. simple lever
C. first-class lever
D. complex lever
E. third-class lever

A

Which of the following is/are properties of a lever?

A. It is a flexible structure.
B. It is the weight that opposes the applied force.
C. It is the effort produced by the muscle contraction.
D. It moves on a fulcrum.
E. All of the answers are correct.

D

Flexion of the forearm at the elbow involves the use of the principle of (a) ________ lever(s).

A. third-class
B. first-class
C. first- and second-class
D. second-class
E. first- and third-class

A

The contraction of the hamstring muscles causes flexion at the knee. This movement is an example of which type of lever?

A. a first-class lever
B. a third-class lever
C. a fourth-class lever
D. a second-class lever

B