Final Exam 4

A typical neuron will have a resting membrane voltage of about ___. A) -90 mV B) -70 mV C) 0 mV D) +35 mV E) +60 mV

-70 mV

Motor nerve fibers release a neurotransmitter called ___, which makes skeletal muscle fibers contract.

Acetylcholine

How would severing the tendon attached to a muscle affect the muscle's ability to move a body part? A) Uncontrolled movement would result from a severed tendon. B) Movement would be greatly exaggerated with no tendon. C) No movement is possible without a muscle to bone connection. D) Limited movement would result.

No movement is possible without a muscle to bone connection.

Oxygen debt is the amount of extra oxygen needed after an exercise to do all of the following except A) oxidize lactic acid. B) lower the metabolic rate to a resting level. C) replenish the reserves of creatine phosphate. D) replenish the reserves of oxygenated myoglobin. E) replenish the oxygen dissolved in the extracellular fluids.

Replenish the reserves of creatine phosphate

Can a skeletal muscle contract without shortening? A) Yes; isometric contractions produce no movement. B) No; resistance is always less than force generated. C) Yes; concentric contractions are common. D) No; contraction implies movement.

Yes; isometric contractions produce no movement.

Each end of a sarcomere is marked by A) terminal cisternae. B) a Z disc. C) an H band. D) an A band. E) an I band.

a Z disc

What would damage to the afferent division of the PNS affect? A) ability to learn new facts B) ability to experience motor stimuli C) ability to experience sensory stimuli D) ability to remember past events

ability to experience sensory stimuli

Neurons follow the ___ law, meaning they either fire at maximum voltage or not at all.

all or none law

Because of the absence of ___, damaged nerve fibers in the CNS cannot regenerate. A) a myelin sheath B) an epineurium C) an endoneurium D) neuroglia E) an axolemma

an endoneurium

interneurons A) Are found only in the CNS B) Carry only sensory impulses C) Carry only motor impulses D) Only connect sensory neuron to other sensory neurons E) Only connect motor neuron to other motor neurons

are found only in the CNS

In a ___ muscle, the fascicles diverge from both sides of a central tendon.

bipennet

The central nervous system consists of the ___ and ___.

brain, spinal cord

All of the following events occur when a nerve signal reaches a synaptic knob. The one that occurs first is A) ACh is reabsorbed by the presynaptic cell B) synaptic vesicles undergo exocytosis. C) ACh binds to a receptor D) ligand-gated ion channels open on the postsynaptic cell E) calcium ions enter the synaptic knob

calcium ions enter the synaptic knob

Where would you expect the greatest concentration of Ca2+ in resting skeletal muscle to be? A) T tubules B) surrounding the mitochondria C) within sarcomeres D) cisternae of the sarcoplasmic reticulum

cisternae of the sarcoplasmic reticulum

What effect would blocking voltage-regulated calcium channels at a cholinergic synapse have on synaptic communication? A) Communication would cease. B) Communication would be enhanced. C) Communication would be misdirected. D) Communication would continue as before.

communication would cease

Why is it difficult to contract a muscle that has been overstretched? A) Myosin filaments break. B) Crossbridges can not be formed. C) Z lines are unable to sustain contractile forces. D) Tendons lose elasticity.

cross bridges can not be formed

You have just played a stunning violin concerto, the audience is wild with applause, and you take a deep bow, using your A) gluteus maximus muscles. B) dorsal interosseous muscles. C) extensor hallucis longus muscles. D) iliopsoas muscles. E) lumbrical muscles.

iliopsoas muscles

How would a drug that interferes with cross-bridge formation affect muscle contraction? A) interferes with contraction B) slows contraction C) speeds contraction D) increases strength of contraction

interferes with contraction

The integrative function of the nervous system is associated especially with A) sensory neurons. B) afferent neurons. C) interneurons. D) efferent neurons. E) effectors.

interneurons

During the time that a muscle is shortening but maintaining constant tension, it is undergoing A) isotonic contraction. B) isometric contraction. C) multiple motor unit summation. D) tetanus. E) treppe.

isotonic contraction

Which type of neuroglia would occur in larger than normal numbers in the brain tissue of a person with a CNS infection? A) astrocytes B) microglial cells C) ependymal cells D) oligodendrocytes

microglial cells

___ are neurotransmitters, such as GABA, that are synthesized from amino acids.

monoamines (biogenic amines)

One motor nerve fiber and all the muscle fibers innervated by it are called a ___.

motor unit

In the peripheral nervous system, myelin sheaths have gaps called ___ about 1 mm apart.

nodes of ranvier

At the distal end of a nerve fiber, action potentials have the same voltage as they had at the beginning. That is to say, they are A) saltatory. B) nondecremental. C) refractory. D) irreversible. E) self-propagating.

nondecremental

Acetylcholine is classified as A) a neuropeptide. B) an amino acid. C) an indolamine. D) a catecholamine. E) none of these.

none of these

The levator palpebrae m. is an antagonist of the ___________ m.

obicularis oculi

Muscular walls of the thorax and abdomen are composed of A) oblique and rectus muscles. B) muscles of mastication. C) spinal erector muscles. D) glossal muscles. E) pectoralis muscles.

oblique and rectus muscles

A bipolar neuron has A) two axons arising from the soma B) one axon and one dendrite arising from the soma C) two axons and multiple dendrites arising from the soma D) two dendrites arising from the soma E) two somas

one axon and one dendrite arising from the soma

___ are straplike muscles of uniform width whose fascicles all run in the same direction. A) Convergent muscles B) Parallel muscles C) Rectilinear muscles D) Fusiform muscles E) Pennate muscles

parallel muscles

The ___ nervous system carries brain and spinal cord signals to other organs. A) autonomic B) peripheral C) central D) craniospinal E) efferent

peripheral

Deep muscles are called A) superficialis. B) extrinsic. C) profundus. D) intrinsic. E) externus.

profundus

All of the following properties are essential to the function of muscle tissue except A) irritability. B) contractility. C) extensibility. D) elasticity. E) striations.

striations

The junction where one neuron meets another is called a/an ___.

synapse

In a resting muscle, an organelle called the ___ contains a concentrated solution of calcium.

terminal cisternae

Which of the following muscles does not act on the tibia or fibula? A) vastus medialis B) rectus femoris C) biceps femoris D) tibialis anterior E) Semimembranosus

tibialis anterior

During treppe, why does tension in a muscle gradually increase even though the strength and frequency of the stimulus are constant? A) Increased blood flow improves contraction. B) Sarcomeres shorten with each contraction. C) Calcium ion concentration increases with successive stimuli. D) Generated heat improves contraction.

Calcium ion concentration increases with successive stimuli.

Why are cardiac and smooth muscle contractions more affected by changes in extracellular Ca2+ than are skeletal muscle contractions? A) Extracellular Ca2+ inhibits actin. B) Crossbridges are formed extracellularly. C) Most calcium for contractions comes from SR stores. D) Most calcium for contractions comes from extracellular fluid.

Most calcium for contractions comes from extracellular fluid.

Why would a sprinter experience muscle fatigue before a marathon runner would? A) Sprinters cannot utilize ATP for long periods of time. B) Sprinters' muscles are most efficient aerobically. C) Sprinters' muscles are most efficient anaerobically. D) Sprinters' muscles are weaker.

Sprinters' muscles are most efficient anaerobically.

Which of these processes occurs during the contraction of skeletal muscle? A) Calcium ions are taken up by the terminal cisternae. B) The myofilaments become shorter. C) Z discs move closer together. D) Calcium ions dissociate from troponin. E) Head of myosin binds to active sites of actin.

Z discs move closer together

Why does skeletal muscle appear striated when viewed through a microscope? A) Z lines and myosin filaments align within the tissue. B) Glycogen reserves are linearly arranged. C) Capillaries regularly intersect the myofibers. D) Actin filaments repel stain, appearing banded.

Z lines and myosin filaments align within the tissue.

Which of the following is an effector? A) an afferent neuron B) an efferent neuron C) a gland D) a sense organ E) an interneuron

a gland

What would you expect to happen to a resting skeletal muscle if the sarcolemma suddenly became very permeable to Ca2+? A) increased strength of contraction B) decreased cross bridge formation C) decreased ability to relax D) both A and C

both A and C

Each muscle fiber is surrounded by its own connective tissue sheath called _________.

endomysium

The events that occur between the time a nerve fiber stimulates a muscle fiber and the time the muscle fiber begins to contract are called ___.

excitation, contraction, coupling

All skeletal muscles have their origins and insertions on bone. True or false?

false

Axonal transport is the mechanism for transmitting action potentials along an axon. True or false?

false

Contraction of the diaphragm expels air from the lungs. True or false?

false

Large nerve fibers conduct signals more slowly than small ones. True or false?

false

One somatic motor neuron can innervate only one skeletal muscle fiber. True or false?

false

Skeletal muscles work alone. True or false?

false

The antagonist is a muscle that generally acts to prevent movement of a bone. True or false?

false

The interosseous muscles are fusiform. True or false?

false

The orbicularis oculi moves the eye, for example when you are reading a page of print. True or false?

false

Troponin is part of the thick filament of a sarcomere. True or false?

false

Muscle fibers are arranged in bundles called ___.

fascicles

Jill suffers a severe cut that severs the tendon that attaches the insertion of the flexor carpi ulnaris. As a result of this injury, what action is difficult for her to perform? A) flex her forearm B) flex her elbow C) flex her ulna D) flex her shoulder E) flex and adduct her palm

flex and adduct her palm

What feature of cardiac muscle tissue allows the heart to act as a functional syncytium? A) striations B) intercalated discs C) gap junctions D) short T tubules without triads

gap junctions

The two-head muscle of the calf is the ___.

gastrocnemius

Compared to the endocrine system, the nervous system usually A) has more local, specific effects B) reacts more slowly to a stimulus C) does not employ chemical messengers D) continues to respond long after the stimulus ceases E) secretes chemical messengers into the bloodstream

has more local, specific effects

The teres major and teres minor originate on the ___ and insert on the ___. A) humerus...scapula B) tibia...calcaneus and talus C) os coxae...femur D) femur...tibia E) scapula...humerus

humerus, scapula

If a poison inhibits the activity of acetylcholinesterase, a muscle A) will switch to anaerobic fermentation. B) may be unable to contract. C) will fatigue more quickly. D) will fatigue more slowly. E) may be unable to relax.

may be unable to contract

Predict what would happen to a muscle if the motor end plate failed to produce acetylcholinesterase. A) Muscle would lose strength. B) Muscle would be unable to contract. C) Muscle would lock in a state of contraction. D) Muscle would contract repeatedly.

muscle contraction would lock in a state of contraction

The bright red color of skeletal muscle is due mainly to its A) myoglobin. B) A bands. C) troponin. D) tropomyosin. E) myosin.

myoglobin

The bodies of the Schwann cells constitute the A) axolemma B) axoplasm C) myelin D) endoneurium E) neurilemma

neurilemma

One pathway in the central nervous system consists of three neurons, another of five neurons. If the neurons in the two pathways are identical, which pathway will transmit impulses more rapidly?

pathway with three neurons

The anterior aspect of the thigh is dominated by the ___, a large muscle with four heads.

quadriceps femoris

The effect of a particular neurotransmitter is dependent upon the properties of the ________, not the ________. A) substrate; receptor. B) propagation; neurotransmitter. C) neurotransmitter; receptor. D) hormone; neurotransmitter. E) receptor; neurotransmitter.

receptor; neurotransmitter

During abdominal surgery, the surgeon makes a cut through the muscle directly to the right of the linea alba. The muscle that is being cut would be the ___ A) digastric. B) external abdominal oblique. C) rectus abdominus. D) scalenus. E) splenius.

rectus abdominus

Unlike local potentials, action potentials are A) decremental B) detrimental C) self-propagating D) graded E) reversible

self-propagating

A tissue sample shows unipolar neurons. Are these more likely to be sensory neurons or motor neurons?

sensory

The ___ theory is the current model of how a muscle fiber contracts.

sliding filament

Which type of muscle fibers would you expect to predominate in the large leg muscles of someone who excels at endurance activities, such as cycling or long-distance running? A) slow fibers B) fast fibers C) nonvascular fibers D) thick, glycogen-laden fibers

slow fibers

Nissl bodies are located in the ___ of a neuron. A) soma B) dendrite C) myelin sheath D) telodendria E) synaptic knobs

soma

Several body orifices are regulated by circular muscles called___.

sphincters

The prime mover of neck flexion is a prominent muscle on the side of the neck called the ___.

sternocleidomastoid

The ___ acts synergistically with the masseter. A) levator scapulae B) splenius capitis C) Buccinators D) Temporalis E) zygomaticus major

temporalis

Action potentials are propagated from the surface to the interior of a muscle fiber by way of A) the T tubules. B) the sarcoplasmic reticulum. C) the endomysium. D) the myofibrils. E) the sarcomeres.

the T tubules

The trigger zone of a neuron includes A) the dendrites. B) the synaptic knobs. C) each node of Ranvier. D) each internode. E) the axon hillock.

the axon hillock

Tom, a trumpet player, asks you which muscles he should develop in order to be a better trumpeter. What would you tell him? A) the masseter and buccinators B) the buccinator and orbicularis oris C) the orbicularis oris and risorius D) the risorius and zygomaticus E) the levator labii and mentalis

the buccinator and orbicularis oris

Which of the following perineal muscles exhibits the greatest difference between males and females? A) the coccygeus B) the deep transverse perineus C) the levator ani D) the bulbospongiosus E) the external anal sphincter

the bulbospongiosus

When you hyperextend your fingers, as in admiring a ring, you may be able to see three or four prominent tendons stand out on the back of your hand. These tendons arise from A) the flexor digitorum superficialis. B) the flexor digitorum profundus. C) the lumbrical muscles. D) the dorsal interossei. E) the extensor digitorum.

the extensor digitorum

The calcaneal (Achilles) tendon arises from A) the gastrocnemius and soleus. B) the peroneus longus and peroneus brevis. C) the lateral rotator muscles. D) the semitendinosus and semimembranosus. E) the adductor longus, adductor brevis, and adductor magnus.

the gastrocnemius and soleus

The word hallucis in the name of a muscle means pertaining to A) the thumb. B) the great toe. C) the ankle. D) the wrist. E) the mind.

the great toe

The strength of a muscle depends on all the following factors except A) the number of muscle fibers innervated by each nerve fiber. B) multiple motor unit summation. C) the degree of stretch just before it was stimulated. D) the diameter of its fibers. E) the length of its sarcomeres.

the length of its sarcomeres

Which of the following muscles is bipennate? A) the pectoralis major B) the biceps brachii C) the palmar interosseous muscles D) the rectus femoris E) the deltoid

the rectus femoris

All of the following are intrinsic muscles of the head except A) the temporalis. B) the buccinator. C) the sternocleidomastoid. D) the risorius. E) the nasalis.

the stereocleidomastoid

If a nerve fiber is firing 300 times per second at time A and 500 times per second at time B, it probably means that at time B A) its refractory period was over B) the stimulus was stronger C) it was exhibiting spatial summation D) it was exhibiting temporal summation E) it was not obeying the all-or-none law

the stimulus was stronger

Local potentials differ from action potentials in all of these ways except that A) they are reversible. B) they are of variable voltage. C) they are sometimes inhibitory. D) they obey the all-or-none law. E) they spread only short distances from the point of stimulation.

they obey the all or none law

Which of the following muscles is not externally visible on the trunk of the body? A) latissimus dorsi B) teres major C) pectoralis major D) Trapezius E) transversus abdominis

transversus abdominus

The largest muscle of the upper back is the ________ muscle.

trapezius

In a relaxed muscle fiber, the active sites of actin are blocked by A) troponin C. B) tropomyosin. C) calcium ions. D) myosin heads. E) intermediate filaments.

tropomyosin

Which of the following is considered to be a regulatory protein of the myofilaments? A) G actin B) Calmodulin C) Cholinesterase D) Troponin E) Myosin

troponin

A contracted muscle cannot relax in the absence of ATP. True or false?

true

Chemical synapses are the most abundant in the body. True or false?

true

Dendrites do not release neurotransmitters. True or false?

true

If a neuron becomes hyperpolarized, it is less likely to fire. True or false?

true

Involuntary muscle can be either smooth or striated. True or false?

true

Myelinated nerve fibers conduct signals faster than unmyelinated fibers. True or false?

true

Not all synapses employ neurotransmitters. True or false?

true

Tetabys us a normal part of muscle contraction, not just the name of the bacterial disease. True or false?

true

The actions of a synergist are similar but not necessarily identical to those of a prime mover at the same joint. True or false

true

The bone at a muscle's origin shows little or no movement when that muscle contracts. True or false?

true

Unlike skeletal muscle, smooth muscle often contracts even when it is not stimulated by a nerve. True or false?

true

When you swallow, you can feel your larynx bob upwards. This results from the action of certain muscles in the infrahyoid group. True or false?

true

The pronator teres and pronator quadratus A) depress the scapula. B) rotate the scapula. C) turn the palm downward. D) turn the palm upward. E) flex the elbow.

turn the palm downward

The preferred site for intramuscular (IM) injections in infants and children is the _____ A) vastus lateralis. B) gluteus minimus. C) soleus. D) gluteus maximus. E) deltoid.

vastus lateralis

The muscles that insert on the tibial tuberosity by way of the patellar ligament include all of the following, except the A) vastus superiorus. B) vastus intermedius. C) vastus lateralis. D) vastus medialis. E) rectus femoris.

vastus superiorus