Introduction to Human Physiology Chapter 6 Practice Questions

ALS (amyotrophic lateral sclerosis) is a disease that results in progressive paralysis. While the ultimate cause is unknown, ___ is the direct cause of the paralysis a) malfunctioning mitochondria b) degeneration of motor neurons c) inflammation d) UV light

b) degeneration of motor neurons

Which layer of connective tissue surrounds each skeletal muscle fiber? a) epimysium b) endomysium c) perimysium d) aponeurosis

b) endomysium

Which of these muscles is named for the arrangement of its fascicles? a) adductor longus b) external oblique c) deltoid d) temporalis

b) external oblique

A smooth, sustained contraction, with no evidence of relaxation, is called a) summing of contractions b) fused, or complete, tetanus c) a twitch d) unfused, or incomplete, tetanus

b) fused, or complete, tetanus

Which chemical is produced during vigorous exercise when the supply of oxygen is limited or inadequate? a) carbon dioxide b) lactic acid c) glycogen d) creatine

b) lactic acid

An inherited disease that causes muscles to degenerate and atrophy is known as a) myasthenia gravis b) muscular dystrophy c) torticollis d) cystic fibrosis

b) muscular dystrophy

muscle tissue composed of branching cells and intercalated discs

cardiac muscle tissue

muscle tissue found only in the heart

cardiac muscle tissue

What creates the alternating light and dark bands that provides the striation pattern on skeletal muscle tissue? a) H zones and M lines b) sarcoplasm and sarcolemma c) thick filaments and myosin heads d) A bands and l bands e) Z discs and H zones

d) A bands and l bands

While doing "jumping jacks" during an exercise class, your arms and legs move laterally away from the midling of your body. This motion is called a) extension b) flexion c) circumduction d) abduction e) adduction

d) abduction

What is released by axon terminals into the synaptic cleft to stimulate a muscle to contract? a) myosin heads b) actin c) potassium ions d) acetylcholine e) sodium ions

d) acetylcholine

The heads of the myosin myofilaments are called ___ when they link the thick and thin filaments together during skeletal muscle contraction a) neuromuscular junctions b) synapses c) motor units d) cross bridges

d) cross bridges

Skeletal muscle, as a whole, can generate different amounts of force, and different degrees of shortening, in response to stimuli. What is this concept called? a) action potential b) twitch c) fused, or complete, tetanus d) graded response e) incomplete, or unfused, tetanus

d) graded response

What happens to a muscle when the nerve supplying that muscle is cut? a) muscular dystrophy develops b) the muscle hypertrophies c) myasthenia gravis develops d) muscle paralysis and atrophy occur

d) muscle paralysis and atrophy occur

The point of muscle attachment to an immovable or less movable bone is known as the a) action b) insertion c) innervation d) origin

d) origin

What organelle wraps and surrounds the myofibril and stores calcium? a) sarcolemma b) cross bridge c) sarcomere d) sarcoplasmic reticulum

d) sarcoplasmic reticulum

Which term does NOT describe smooth muscle cells? a) involuntary b) nonstriated c) visceral d) skeletal

d) skeletal

What must rush into a cell to promote its depolarization? a) calcium ions b) acetylcholinesterase c) acetylcholine d) sodium ions e) potassium ions

d) sodium ions

Which movement is associated with the hand but actually occurs in the forearm? a) dorsiflexion b) opposition c) inversion d) supination

d) supination

What is covered by the endomysium? a) fascicles of muscle cells b) myofibrils c) an entire muscle d) smooth muscle only e) an individual muscle cell

e) an individual muscle cell

Which of the following is a type of isometric exercise in which muscles increase in size and strength? a) swimming b) jogging c) dancing d) biking e) lifting weights

e) lifting weights

A motor neuron and all of the skeletal muscle fibers it stimulates are termed a a) neuromuscular junction b) synaptic cleft c) myofilament d) neurotransmitter e) motor unit

e) motor unit

Which of the following is an example of an isometric contraction? a) shaking the head as to say "no" b) bending the elbow c) nodding the head as to say "yes" d) rotating the arm e) pushing against an immovable wall

e) pushing against an immovable wall

type of movement that turns the sole of the foot medially

inversion

type of movement that points the toes

plantar flexion

the movement of a bone around its longitudinal axis

rotation

muscle tissue that is multinucleate

skeletal muscle tissue

muscle tissue that maintains posture, body position, and stabilizes joints

skeletal muscle tissue

voluntary muscle tissue

skeletal muscle tissue

muscle tissue that activates arrector pili muscles to stand hairs on end

smooth muscle tissue

muscle tissue that dilates and constricts the pupils of our eyes

smooth muscle tissue

performs very slow, sometimes rhythmic contractions

smooth muscle tissue

type of movement that allows you to carry a soup bowl

supination

primary action of deltoid

abduction

the movement of a limb away from the body midline

abduction

primary action of the adductor muscles

adduction

the movement of a limb toward the body midline

adduction

Which method of regenerating ATP during muscle contraction can produce lactic acid? a) anaerobic glycolysis b) creatine phosphate c) direct phosphorylation d) oxidative phosphorylation e) aerobic celular respiration

a) anaerobic glycolysis

What condition results if muscles are not used, such as when immobilized in a cast for healing a broken bone? a) atrophy b) hypertrophy c) spina bifida d) lordosis e) scoliosis

a) atrophy

What mineral is released within muscles to trigger contraction? a) calcium b) potassium c) ATP d) sodium

a) calcium

Striated involuntary muscle tissue found in the heart is a) cardiac muscle b) smooth muscle c) skeletal muscle d) dense irregular e) dense regular

a) cardiac muscle

What type of muscle tissue is both striated and involuntary? a) cardiac muscle b) smooth muscle c) skeletal muscle d) visceral muscle

a) cardiac muscle

Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as a) contractility b) irritability c) extensibility d) elasticity

a) contractility

Which of these terms refers to the shape of a muscle? a) deltoid b) rectus c) mastoid d) biceps

a) deltoid

Contractions in which muscles shorten and produce movement are known as a) isotonic contractions b) isometric contractions c) twitches d) resistance exercises

a) isotonic contractions

What is the molecular basis of Duchenne's muscular dystrophy? a) muscle fibers lack a protein that helps to maintain the sarcolemma b) there is a shortage of acetylcholine receptors at neuromuscular junctions c) myosin and actin remained fixed in place d) calcium channels at the axon terminal fail to open

a) muscle fibers lack a protein that helps to maintain the sarcolemma

Which of these muscles is located on the ventral (anterior) side of the body? a) pectoralis major b) occipitalis c) gastrocnemius d) gluteus medius e) latissiumus dorsi

a) pectoralis major

Which of these muscles is located in the neck? a) sternocleidomastoid b) deltoid c) occipitalis d) buccinator

a) sternocleidomastoid

What term refers to a muscle that aids another muscle by producing the same movement or reducing undesirable movements? a) synergist b) antagonist c) fixator d) prime mover

a) synergist

What is acetylcholine? a) a component of thick myofilaments b) a neurotransmitter that stimulates skeletal muscle to contract c) an oxygen-binding protein d) an ion pump on the postsynaptic membrane e) a source of energy for muscle contraction

b) a neurotransmitter that stimulates skeletal muscle to contract

What initiates an action potential on a muscle cell? a) myosin cross bridges binding to actin b) acetylcholine binding to receptors on the sarcolemma within the neuromuscular junction c) ATP d) Acetylcholinesterase

b) acetylcholine binding to receptors on the sarcolemma within the neuromuscular junction

There are three types of muscle tissue. Which of the following is classified as part of the muscular system? a) the heart b) all skeletal muscles c) all muscle tissue, including muscle of arteries, eyes, and the heart

b) all skeletal muscles

Muscles that perform opposite actions to one another are termed a) synergists b) antagonists c) prime movers d) fixators

b) antagonists

What term refers to a smooth, sustained contraction? a) isometric contraction b) complete tetanus c) muscle twitch d) isotonic contraction

b) complete tetanus

According to the sliding filament theory, how does muscle contraction occur? a) both thick and thin filaments shorten as the muscle contracts b) myosin heads form cross bridges and pull thin filaments, causing them to slide c) myosin heads attach and detach from thin filaments, causing thin filaments to shorten d) a bands bunch up and shorten as myosin heads attach to thin filaments

b) myosin heads form cross bridges and pull thin filaments, causing them to slide

What is key to offsetting the effects of aging on the muscular system? a) sleeping 6-8 hours a night b) regular exercise c) drinking plenty of water d) taking vitamins

b) regular exercise

What can older individuals do to increase muscle strength? a) get sufficient rest every day b) regularly use hand weights and practice leg lifts

b) regularly use hand weights and practice leg lifts

What type of exercise causes increase in muscle size? a) anaerobic exercise b) resistance exercise c) aerobic exercise d) infrequent exercise

b) resistance exercise

What term describes the rotation of a bone around its longitudinal axis? a) inversion b) rotation c) dorsiflexion d) circumduction

b) rotation

The gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscle cell is called the a) sarcomere b) synaptic cleft c) motor unit d) neuromuscular junction e) cross bridge

b) synaptic cleft

Which one of the following is composed mostly of the protein myosin? a) Z discs b) thick filaments c) light bands d) thin filaments e) all myofilaments

b) thick filaments

What changes occur in the sarcomere during muscle contraction? a) The thin filament shortens b) I band increases in length c) Z discs move closer together d) A band decreases in length

c) Z discs move closer together

The mechanical force of contraction is generated by a) the "accordian-like" folding of thin and thick filaments b) the temporary disappearance of thin filaments c) a sliding of thin filaments past thick filaments d) shortening of the thin filaments e) shortening of the thick filaments

c) a sliding of thin filaments past thick filaments

What is the unstoppable electrical current that travels down the length of the entire surface of a sarcolemma? a) neuromuscular junction b) neurotransmitter c) action potential d) acetylcholine

c) action potential

Which movement is opposite to abduction? a) supination b) circumduction c) adduction d) flexion e) rotation

c) adduction

Which of these increases as muscles age? a) muscle strength b) muscle mass c) amount of connective tissue in a muscle

c) amount of connective tissue in a muscle

Neurotransmitters are released upon stimulation from a nerve impulse from the a) sarcoplasmic reticulum b) sarcolemma of the muscle cell c) axon terminals of the motor neuron d) thick filaments e) myofibrils

c) axon terminals of the motor neuron

Striated involuntary muscle tissue is classified as ___ muscle a) skeletal b) smooth c) cardiac d) either smooth or skeletal

c) cardiac

What is the function of creatine phosphate? a) catalyzes aerobic respiration b) triggers anaerobic respiration c) directly regenerates ATP from ADP within a muscle cell d) makes oxygen available for aerobic respiration

c) directly regenerates ATP from ADP within a muscle cell

What term describes the ability of a muscle to vary its degree of shortening to generate the strength needed to lift a 5 lb weight, a 7 lb weight, and finally a 10 lb weight? a) isotonic contractions b) isometric contractions c) graded responses d) twitch

c) graded responses

Which of these characteristics applies only to cardiac muscle tissue? a) involuntary b) striations c) intercalated discs d) stimulated by hormones

c) intercalated discs

One neuron and all the skeletal muscles it stimulates is known as a a) synaptic cleft b) sarcoplasmic reticulum c) motor unit d) neuromuscular junction

c) motor unit

Amelie, a 29 year old woman, complained to her doctor of being constantly fatigued and having difficulty swallowing. Her speech is slurred and her eyelids are droopy. Amelie most likely has a) tetanus b) Duchenne's muscular dystrophy c) myasthenia gravis d) torticollis

c) myasthenia gravis

Which connective tissue bundles muscle fibers into fascicles? a) endomysium b) tendons c) perimysium d) epimysium

c) perimysium

The plasma membrane of a skeletal muscle is called the a) sarcomere b) myofilament c) sarcolemma d) sarcoplasm e) sarcoplasmic reticulum

c) sarcolemma

Which type of muscle tissue contracts most quickly upon stimulation? a) cardiac b) tendons c) skeletal d) smooth e) visceral

c) skeletal

Creatine phosphate (CP) functions within the muscle cells by a) storing energy that will be transferred to ATP to resynthesize ADP as needed b) forming a chemical compound with actin c) inducing a conformational change in the myofilaments d) forming a temporary chemical compound with myosin e) storing energy that will be transferred to ADP to resynthesize ATP as needed

e) storing energy that will be transferred to ADP to resynthesize ATP as needed

A sarcomere is a) the nonfunctional unit of skeletal muscle b) the wavy lines on the cell, as seen in a microscope c) the area between two intercalated discs d) a compartment in a myofilament e) the contractile unit between two Z discs

e) the contractile unit between two Z discs

The condition of skeletal muscle fatigue can be best explained by a) a total lack of ATP in the body b) inadequate numbers of mitochondria in muscle cells c) the all-or-none law d) the inability to generate sufficient quantities of ATP due to feedback regulation of synthesis e) the inability of the muscle to contract even if it is being stimulated

e) the inability of the muscle to contract even if it is being stimulated

primary action of the erector spinae

extension

primary action of the rectus abdominis

flexion

type of movement that decreases the angle of the joint

flexion