BL 3030 A&P Allen test answers test no. 3 Ch.9 and Ch. 11

A lack of mitochondria within skeletal muscle fibers would impair which ATP yielding chemical process? a. anaerobic respiration b. aerobic respiration c. both anaerobic and aerobic respiration are correct

aerobic respiration

Dendrites a. are the input part of the neuron b. conduct action potentials away from the cell body c. are generally long and unbranched d. form synapses with the microglia e. contain the trigger zone

are the input part of the neuron

List the following structures in order from smallest to largest: (1) muscle fiber (2) Myofilament (3) Myofibril (4) Muscle fascicle

(2) Myofilament, (3) Myofibril, (1) muscle fiber, (4) muscle fascicle

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

Gaps or interruptions in the myelin sheath are called a. internodes b. tight junctions c. neurofilaments d. nodes of Ranvier e. gap junctions

nodes of Ranvier

A sarcomere extends from a. one Z disk to an adjacent Z disk b. one T tubule to the next T tubule c. the middle of the I band to the middle of the A band d. the H zone to the I band e. the M line to the next M line

one Z disk to an adjacent Z disk

When repolarization in the plasma 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 decrease in the number of voltage-gated Ca2+ ion channels in the presynaptic terminal would a. enhance transmission across the synapse b. reduce or inhibit transmission across the synapse c. have no effect on transmission across the synapse d. alter receptors on the postsynaptic membrane e. increase exocytosis

reduce or inhibit transmission across the synapse

Muscles exhibit the property of excitability. This means that the muscle a. shortens its length b. recoils to its original resting length c. stretches beyond its normal length d. responds to stimulation by the nervous system e. excites itself

responds to stimulation by the nervous system

The _______________________ is the plasma membrane of a muscle fiber.

sarcolemma

Arrange the following list of biochemical events in the correct sequence. (1) an action potential is conducted deep into the muscle by the T tubule (2) calcium ions bind to troponin (3) the membranes of the sarcoplasmic reticulum become more permeable to calcium ions (4) calcium ions diffuse into the sarcoplasm around the myofibril (5) the troponin-tropomyosin complex moves exposing active sites a. 1, 5, 2, 3, 4 b. 1, 3, 4, 2, 5 c. 1, 2, 3, 4, 5 d. 1, 3, 2, 5, 4

1, 3, 4, 2, 5

In hyperpolarization a. K+ tend to diffuse out of the cell b. the plasma membrane's permeability to K+ decreases c. the resting membrane potential moves closer to zero d. Na+ enter the cell in large numbers e. the resting membrane potential becomes more positive

K+ tend to diffuse out of the cell

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

During the contraction phase of a muscle twitch, a. acetylcholine stimulates the presynaptic terminal b. Na+ diffuse into the muscle fiber c. actin-myosin cross-bridges form d. Ca2+ are transported back to the sarcoplasmic reticulum e. the action potential travels down the T tubule

actin-myosin cross-bridges form

True or false. Gray matter has little myelination, whereas white matter has abundant myelination.

True

Synaptic vesicles in the neuromuscular junction contain a. calcium b. ATP c. acetylcholine d. acetylcholinesterase e. sodium

acetylcholine

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

actin myofilaments

Which of the following will respond to a threshold stimulus with an all-or-none principle? a. a single muscle fiber b. a single motor unit c. a whole muscle d. both a single muscle fiber and a single motor unit are correct e. a single muscle fiber, a single motor unit, and a whole muscle are all correct

both a single muscle fiber and a single motor unit are correct

Match the term with the correct definition. Resting membrane potential a. small change in the resting membrane potential confined to a small area b. charge difference across the plasma membrane when the cell is in an unstimulated state c. larger change in resting membrane potential that spreads over entire surface of the cell d. membrane becomes more positive when Na+ diffuse into the cell e. return to the resting membrane potential

change difference across the plasma membrane when the cell is in an unstimulated state

Acetylcholine is released from the presynaptic terminal by the process of a. exocytosis b. diffusion c. phagocytosis d. active transport e. endocytosis

exocytosis

Match the type of smooth muscle with its example location and description: found in the walls of the digestive tract found in the walls of blood vessels often autorhythmic contracts only when stimulated by neurons

found in the walls of the digestive tract---- visceral found in the walls of blood vessels ---- multiunit often autorhythmic --- visceral contracts only when stimulated by neurons --- multiunit

Mr. Miller has been hospitalized for the flu. The flu virus increases membrane permeability to potassium. You would expect his cells to ___________________________. a. depolarize b. repolarize c. isopolarize d. hyperpolarize e. hypopolarize

hyerpolarize

An IPSP is inhibitory because a. changes the threshold of the neuron b. hyperpolarizes the postsynaptic membrane c. prevents Ca2+ entry into the presynaptic terminal d. reduces the amount of neurotransmitter released by the presynaptic terminal e. depolarizes the postsynaptic membrane

hyperpolarizes the postsynaptic membrane

Local hyperpolarization in a synapse is called a/an _______________________. a. excitatory postsynaptic potential b. resting membrane potential c. inhibitory postsynaptic potential d. gap junction potential e. action potential

inhibitory postsynaptic potential

Which of the following is true during the resting membrane potential? a. sodium ion concentration is greater inside cells b. negatively charged proteins are more concentrated outside the cell c. a greater concentration of calcium ions is found inside the cell d. potassium is concentrated primarily inside the cell e. none of the choices reflect what occurs during the resting membrane potential

potassium is concentrated primarily inside the cell

A neuron that conducts pain sensations to the central nervous system would be classified as a/an_______________________________________. a. motor neuron b. sensory or afferent neuron c. efferent neuron d. association neuron e. interneuron

sensory or afferent neuron

When two action potentials arrive simultaneously at two different presynaptic terminals that synapse with the same postsynaptic neuron, a. the direction of the action potential is reversed b. temporal summation occurs c. spatial summation occurs d. hyperpolarization occurs e. threshold is never reached

spatial summation occurs

A series of local potentials causes the membrane potential to move to -80 mV. Predict the result. a. threshold is reached b. depolarization occurs c. the neuron is hyperpolarized d. information of frequency is needed to predict the result e. the neuron releases neurotransmitter in response

the neuron is hyperpolarized

Suppose both excitatory and inhibitory neurons synapse with a single postsynaptic neuron. What determines if an action potential is initiated in the postsynaptic neuron? a. the kind of neuron involved b. the size of the neuron involved c. whether the neuron is myelinated or unmyelinated d. the number of EPSPs in relation to the number of IPSPs e. this situation is not possible in humans

the number of EPSPs in relation to the number of IPSPs

The plasma membrane of an excitable cell is more permeable to K+ because a. of its positive electrical charge b. there are more leak ion channels for K+ than Na+ c. protein molecules cannot exit through the plasma membrane d. calcium ions block Na+ and Cl- channels e. there are more gated channels for K+

there are more leak ion channels for K+ than Na+

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. leak ion channels c. relegated ion channels d. voltage-gated ion channels e. obligated ion channels

voltage-gated ion channels

Mutliunit smooth muscle is located in the a. gastrocnemius b. wall of the GI tract c. wall of blood vessels d. wall of the heart e. reproductive system

wall of blood vessels

Arrange the events of synaptic transmission in correct sequence. (1) sodium ions diffuse into the cell and cause a local potential (2) neurotransmitter binds with receptor on postsynaptic cell (3) neurotransmitter diffuses across the synaptic cleft (4) membrane permeability to sodium ions on postsynaptic cell increases (5) action potential causes release of neurotransmitter a. 5, 2, 3, 4, 1 b. 5, 2, 3, 1, 4 c. 5, 3, 4, 1, 2 d. 5, 4, 3, 2, 1 e. 5, 3, 2, 4, 1

5, 3, 2, 4, 1

Saltatory conduction of an action potential means that a. once one action potential is created, it moves down the axon b. the whole axon depolarizes at the same time c. one action potential stimulates the production of a new action potential at the adjacent site d. an action potential is conducted from one node of Ranvier to the next node

an action potential is conducted from one node of Ranvier to the next node

When a neurotransmitter binds to its receptor and increases the permeability of the postsynaptic membrane to Na+, a. the membrane will be hyperpolarized b. more Cl- will also diffuse into the cell c. an excitatory postsynaptic potential (EPSP) will result d. the membrane will become impermeable to K+ e. Na+ diffuses out of the cell

an excitatory postsynaptic potential (EPSP) will result

LouAnn is being treated for a neurological condition with a specific drug that target neurons deep within the brain. Which glial cell must be bypassed by this drug in order for it to be effective? a. astrocyte b. microglia c. oligodendrocyte d. ependymal cell e. macrophage

astrocyte

Which of the following statements regarding the sliding filament model is false? a. actin and myosin do not shorten during contraction b. both actin and myosin myofilaments shorten during contraction c. the sarcomere shortens d. the I band and H zones become narrower during contraction e. the A band remains constant in length

both actin and myosin myofilaments shorten during contraction

An inhibitory postsynaptic potential (IPSP) can result from the ____________________________________ a. influx of Ca2+ b. influx of Na+ c. influx of Cl- d. outflow of K- e. both influx of Cl- and outflow of K+ are correct

both influx of Cl- and outflow of K+ are correct

When an action potential reaches the presynaptic terminal, a. calcium ions diffuse into the presynaptic terminal through voltage-gated ion channels b. acetylcholine moves into the presynaptic terminal c. a local potential is generated in the presynaptic terminal d. ligand-gated ion channels in the presynaptic terminal are opened e. nothing else happens

calcium ions diffuse into the presynaptic terminal through voltage-gated ion channels

Which of the following is NOT a function of skeletal muscle? a. body movement b. maintenance of posture c. respiration d. constriction of organs e. production of heat

constriction of organs

A drug that interferes with the active transport of Ca2+ from the sarcoplasm back into the sarcoplasmic reticulum would result in a. relaxation of the muscle fiber b. contraction with no relaxation c. muscle hypertrophy d. fibrosis of the muscle e. an imbalance of blood calcium

contraction with no relaxation

The sensory (afferent) division of the peripheral nervous system a. transmits action potentials to sensory organs b. conveys action potentials to the CNS c. stimulates glands to release hormones d. stimulates muscle contractions e. does not involve sensory receptors

conveys action potentials to the CNS

During resting conditions, _________________________________ is synthesized to store energy. a. Ca2+ b. creatine phosphate c. creatinine d. lactate e. pyruvate

creatine phosphate

Rigor mortis occurs after death because a. cross-bridges form but can't release b. Ca2+ is actively transported back to the sarcoplasmic reticulum c. anaerobic respiration is occuring d. myosin levels decline at death e. cross-bridges never form

cross-bridges form but can't release

Which of the following situations occurs in electrically excitable cells? a. when Na+ ion channels open, K+ ion channels close b. the sodium-potassium pump moves sodium into the cell c. depolarization causes voltage-gated sodium ion channels to open d. sodium ion channels are opened by high extracellular calcium levels e. the opening and closing of ligand-gated channels cause depolarization

depolarization causes voltage-gated sodium ion channels to open

Hydrocephaly is a condition whereby cerebrospinal fluid accumulates around the brain. What supportive cells continue CSF production despite it backing up in the subarachnoid space? a. astrocytes b. microglia c. oligodendrocytes d. macrophages e. ependymal cells

ependymal cells

Which of the following is true about skeletal muscle? a. sensory neurons stimulate muscles to contract b. there are very few blood vessels in skeletal muscle c. every muscle fiber receives a branch from an axon from the nerve d. there are very few nerve fibers in a muscle e. all of the choices are true

every muscle fiber receives a branch from an axon from the nerve

Axons a. contain the nucleus b. are numerous extensions from each neuron c. do not have a trigger zone d. have a distal portion that branches to form the presynaptic terminals e. do not have a resting membrane potential

have a distal portion that branches to form the presynaptic terminals

A child ingested an organophosphate poison used to kill insects. Soon the child's muscles began spastic contractions. Predict what occurred at the synaptic cleft. a. decreased release of acetylcholine from presynaptic neurons b. increased accumulation of acetylcholine in the synapse c. binding of the poison to acetylcholine receptors leading to inhibition of stimulation d. increased breakdown of acetylcholine in the synaptic cleft e. both increased accumulation of acetylcholine in the synapse and increased breakdown of acetylcholine in the synaptic cleft are correct.

increased accumulation of acetylcholine in the synapse

Damage to a postsynaptic membrane would a. increase neurotransmitter release b. decrease the release of neurotransmitter c. increase neurotransmitter production d. interfere with the ability to respond to neurotransmitter

interfere with the ability to respond to neurotransmitter.

Physiological contracture a. occurs when muscles are resting b. is a condition in which cross-bridges cannot release c. is caused by an abundance of ATP in muscle fibers d. results when muscles are well exercised e. results when the neurotransmitter remains in the receptor

is a condition in which cross-bridges cannot release

The central nervous system a. is the site for processing information b. initiates visual and auditory stimuli c. consists of 43 pairs of nerves d. is totally involuntary e. does not interact with the peripheral nervous system

is the site for processing information

The refractory period a. is the time during which the tissue cannot respond again b. results in complete and incomplete tetanus c. is the condition in which the muscle fiber only partially relaxes between contractions d. is the condition in which stimuli occur so rapidly that there are no intervening relaxations e. is the constant tension produced by muscles for long periods of time

is the time during which the tissue cannot respond again

Match the term with the correct definition. Action potential a. small change in the resting membrane potential confined to a small area b. charge difference across the plasma membrane when the cell is in an unstimulated state c. larger change in resting membrane potential that spreads over entire surface of the cell d. membrane becomes more positive when Na+ diffuse into the cell e. return to the resting membrane potential

larger change in resting membrane potential that spreads over entire surface of the cell

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

Match the term with the correct definition. Depolarization... a. small change in resting membrane potential confined to a small area b. charge difference across the plasma membrane when the cell is in an unstimulated state c. larger change in resting membrane potential that spreads over the entire surface of a cell d. membrane becomes more positive when Na+ diffuses into cell e. return to resting membrane potential

membrane becomes more positive when Na+ diffuses into the cell

Which of the following causes an unequal ion concentration across the resting plasma membrane? a. the functioning of the sodium-chloride pump b. negatively charged proteins not readily diffusing across the plasma membrane c. the attraction of chloride ions to other intracellular anions d. the repulsion of potassium ions by the intracellular anions e. the attraction of sodium ions to chloride ions

negatively charged proteins not readily diffusing across the plasma membrane

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 __________________________________________________

neuromuscular junction

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 the choices are correct

positively charged

As you are lifting a box, someone places extra weight on top of it. For your muscle to continue contracting and lifting the box, the muscle must __________. a. recruit more muscle fibers b. lower its threshold c. reduce its wave summation d. shift from isometric to isotonic contraction e. shift from slow-twitch to fast-twitch mode

recruit more muscle fibers

Match the term with the correct definition. Repolarization a. small change in the resting membrane potential condined to a small area b. charge difference across the plasma membrane when the cell is in an unstimulated state c. larger change in resting membrane potential that spreads over entire surface of a cell d. membrane becomes more positive when Na+ diffuse into cell e. return to the resting membrane potential

return to the resting membrane potential

Hypertrophy of skeletal muscles from weight lifting is caused by an increase in the a. number of muscle fibers b. size of muscle fibers c. number of striations d. number of nuclei within the muscle fibers e. number of muscle cells

size of muscle fibers

Whales are air-breathing aquatic mammals, and some species can remain underwater for long periods of time. What type of skeletal muscle fibers are most likely dominant in these deep diving whales? a. slow fibers b. fast (type IIa) fibers c. fast (type IIb) fibers d. white fibers

slow fibers

Match the term with the correct definition. Local potential a. small change in the resting membrane potential confined to a small area b. charge difference across the plasma membrane when the cell is in an unstimulated state c. larger change in resting membrane potential that spreads over the entire surface of a cell d. membrane becomes more positive when Na+ diffuses into cell e. return to the resting membrane potential

small change in the resting membrane potential confined to a small area

Which of the following statements about muscle tissue 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 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

Epimysium a. surrounds individual muscles b. separates muscle fibers c. connects muscles to bones d. is a type of muscle tissue e. is a type of nerve tissue

surrounds individual muscles

In order for muscle relaxation to occur, a. Ca2+ must be transported to troponin b. power strokes slow down c. the active sites on actin must be blocked d. Na+ must be actively transported to troponin e. the active sites on myosin must be uncovered

the active sites on actin must be blocked.

Most metabolic and regulatory functions in a neuron happen where? a. the axon b. the cell body or soma c. the dendrites d. the axon hillock e. the schwann cell

the cell body or soma

What is a cross-bridge? 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

the combination of myosin heads with active sites on actin molecules

What is the power stroke? 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

the movement of myosin head while attached to actin myofilament

Which of the following is true concerning isotonic eccentric contraction? a. the muscle shortens, but tension remains constant b. the muscle lengthens, but tension remains constant c. the muscle tenses and shortens d. the muscle tenses, but length remains unchanged e. the muscle lengthens, and tension declines

the muscle lengthens, but tension remains constant

Consider a chemical that blocks the action of acetylcholinesterase. What effect does this have on the muscles? a. it would cause paralysis b. it would cause action potentials to be inhibited, thereby rendering the muscle useless c. the body would increase its production of acetylcholine to compensate d. the axons of the motor neurons would atrophy, and the muscle would weaken e. the muscle would have no way to relax, and spastic contractions would result

the muscle would have no way to relax, and spastic contractions would result