Anatomy & Physiology Test#3

Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________. A) astrocytes B) oligodendrocytes C) microglia D) Schwann cells

A) astrocytes

he part of a neuron that conducts impulses away from its cell body is called a(n) ________. A) axon B) dendrite C) neurolemma D) Schwann cell

A) axon

What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called? A) ependymal cells B) Schwann cells C) oligodendrocytes D) astrocytes

A) ependymal cells

Select the correct statement about serial processing. A) Spinal reflexes are an example of serial processing. B) Input travels along several different pathways. C) Smells are processed by serial pathways. D) Memories are triggered by serial processing.

A) Spinal reflexes are an example of serial processing.

Which of the choices below describes the ANS? A) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands B) motor fibers that conduct nerve impulses from the CNS to skeletal muscles C) sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS D) sensory and motor neurons that supply the digestive tract

A) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands

A second nerve impulse cannot be generated until ________. A) the membrane potential has been reestablished B) the Na ions have been pumped back into the cell C) proteins have been resynthesized D) all sodium gates are closed

A) the membrane potential has been reestablished

Saltatory conduction is made possible by ________. A) the myelin sheath B) large nerve fibers C) diphasic impulses D) erratic transmission of nerve impulses

A) the myelin sheath

Which of the following is false or incorrect? A) An excitatory postsynaptic potential occurs if the excitatory effect is greater than the inhibitory effect but less than threshold. B) A nerve impulse occurs if the excitatory and inhibitory effects are equal. C) An inhibitory postsynaptic potential occurs if the inhibitory effect is greater than the excitatory, causing hyperpolarization of the membrane.

B) A nerve impulse occurs if the excitatory and inhibitory effects are equal.

Which of the following is true about the movement of ions across excitable living membranes? A) Ions always move actively across membranes through leakage channels. B) Some ions are prevented from moving down their concentration gradients by ATP-driven pumps. C) Sodium gates in the membrane can open in response to electrical potential changes. D) The bulk of the solutions inside a cell are negatively charged.

B) Some ions are prevented from moving down their concentration gradients by ATP-driven pumps.

Which of the following correctly describes a graded potential? A) long distance signaling B) amplitude of various sizes C) voltage stimulus to initiate D) voltage regulated repolarization

B) amplitude of various sizes

Which of the following describes the nervous system integrative function? A) senses changes in the environment B) analyzes sensory information, stores information, makes decisions C) responds to stimuli by gland secretion or muscle contraction

B) analyzes sensory information, stores information, makes decisions

An inhibitory postsynaptic potential (IPSP) is associated with ________. A) a change in sodium ion permeability B) hyperpolarization C) opening of voltage-regulated channels D) lowering the threshold for an action potential to occur

B) hyperpolarization

In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? The interior is ________. A) positively charged and contains less sodium B) negatively charged and contains less sodium C) negatively charged and contains more sodium D) positively charged and contains more sodium

B) negatively charged and contains less sodium

An impulse from one nerve cell is communicated to another nerve cell via the ________. A) cell body B) synapse C) receptor D) effector

B) synapse

Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials? A) mechanically gated channel B) voltage-gated channel C) leakage channel D) ligand-gated channel

B) voltage-gated channel

Neurons may be classified according to several characteristics. Which of the following is correct? A) Group A fibers are mostly somatic sensory and motor and are the smallest in diameter. B) Group B fibers are highly myelinated and have the highest conduction velocities. C) Group C fibers are not capable of saltatory conduction. D) A small cross-sectional area allows shorter conduction times

C) Group C fibers are not capable of saltatory conduction.

characteristic of neurons? A) They conduct impulses. B) They have extreme longevity. C) They are mitotic. D) They have an exceptionally high metabolic rate.

C) They are mitotic.

Which of the following is not a chemical class of neurotransmitters? A) acetycholine B) amino acid C) biogenic amine D) ATP and other purines E) nucleic acid

E) nucleic acid

Which of the following is not true of graded potentials? A) They are short-lived. B) They can form on receptor endings. C) They increase amplitude as they move away from the stimulus point. D) They can be called postsynaptic potentials.

C) They increase amplitude as they move away from the stimulus point.

An excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle is ________. A) cholinesterase B) norepinephrine C) acetylcholine D) gamma aminobutyric acid

C) acetylcholine

A neuron that has as its primary function the job of connecting other neurons is called a(n) ________. A) efferent neuron B) afferent neuron C) association neuron D) glial cell

C) association neuron

The term central nervous system refers to the ________. A) peripheral and spinal nerves B) brain, spinal cord, and peripheral nerves C) brain and spinal cord D) spinal cord and spinal nerves

C) brain and spinal cord

What is the role of acetylcholinesterase? A) act as a transmitting agent B) amplify or enhance the effect of ACh C) destroy ACh a brief period after its release by the axon endings D) stimulate the production of acetylcholine

C) destroy ACh a brief period after its release by the axon endings

Collections of nerve cell bodies outside the central nervous system are called ________. A) nuclei B) nerves C) ganglia D) tract

C) ganglia

The strongest muscle contractions are normally achieved by ________. A) increasing stimulus above the threshold B) increasing stimulus above the treppe stimulus C) increasing the stimulation up to the maximal stimulus D) recruiting small and medium muscle fibers

C) increasing the stimulation up to the maximal stimulus

The sheath of Schwann is also called the ________. A) myelin sheath B) axolemma C) neurilemma D) white matter

C) neurilemma

The substance released at axon terminals to propagate a nervous impulse is called a(n) ________. A) ion B) cholinesterase C) neurotransmitter D) biogenic amine

C) neurotransmitter

Schwann cells are functionally similar to ________. A) ependymal cells B) microglia C) oligodendrocytes D) astrocytes

C) oligodendrocytes

If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon ________. A) the impulse would move to the axon terminal only B) muscle contraction would occur C) the impulse would spread bidirectionally D) the impulse would move to the axon terminal only, and the muscle contraction would occur

C) the impulse would spread bidirectionally

Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane? A) Specific sodium gates will open. B) Specific potassium gates will open. C) Sodium gates will open first, then close as potassium gates open. D) A single type of channel will open, permitting simultaneous flow of sodium and potassium.

D) A single type of channel will open, permitting simultaneous flow of sodium and potassium.

Select the correct statement regarding synapses. A) Cells with gap junctions use chemical synapses. B) The release of neurotransmitter molecules gives cells the property of being electrically coupled. C) Neurotransmitter receptors are located on the axons terminals of cells. D) The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.

D) The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.

Most muscles contain ________. A) a predominance of fast oxidative fibers B) a predominance of slow oxidative fibers C) muscle fibers of the same type D) a mixture of fiber types

D) a mixture of fiber types

The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________. A) resting period B) repolarization C) depolarization D) absolute refractory period

D) absolute refractory period

Nerve cell adhesion molecules (N-CAMs) ________. A) release nerve growth factor B) are found on "pathfinder" neurons C) are crucial in the production of neurotransmitters D) are crucial for the development of neural connections

D) are crucial for the development of neural connections

Bipolar neurons are commonly ________. A) motor neurons B) called neuroglial cells C) found in ganglia D) found in the retina of the eye

D) found in the retina of the eye

When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________. A) postsynaptic potential B) excitatory potential C) action potential D) generator potential

D) generator potential

Ependymal cells _______. A) are a type of neuron. B) are a type of macrophage. C) are the most numerous of the neuroglia. D) help to circulate the cerebrospinal fluid.

D) help to circulate the cerebrospinal fluid.

Which of the following is not a usual result of resistance exercise? A) increase in the efficiency of the circulatory system B) increase in the number of myofibrils within the muscle cells C) increase in the efficiency of the respiratory system D) increase in the number of muscle cells

D) increase in the number of muscle cells

Which of the following is not a function of the autonomic nervous system? A) innervation of smooth muscle of the digestive tract B) innervation of cardiac muscle C) innervation of glands Which of the following is not a function of the autonomic nervous system? A) innervation of smooth muscle of the digestive tract B) innervation of cardiac muscle C) innervation of glands D) innervation of skeletal muscle

D) innervation of skeletal muscle

Which of the following would be recruited later in muscle stimulation when contractile strength increases? A) large motor units with small, highly excitable neurons B) motor units with the longest muscle fibers C) many small motor units with the ability to stimulate other motor units D) motor units with larger, less excitable neurons

D) motor units with larger, less excitable neurons

Immediately after an action potential has peaked, which cellular gates open? A) sodium B) chloride C) calcium D) potassium

D) potassium

Fatigued muscle cells that recover rapidly are the products of ________. A) intense exercise of long duration B) intense exercise of short duration C) slow exercise of long duration D) slow exercise of short duration

D) slow exercise of short duration

Which of the following is not a function of astrocytes? A) support and brace neurons B) anchor neurons to blood vessels C) guide the migration of young neurons, synapse formation, and helping to determine capillary permeability D) control the chemical environment around neurons E) provide the defense for the CNS

E) provide the defense for the CNS

The giant protein titin maintains the orgainzation of the ___ assisting in muscle stretching. a) A band b) I band c) Z disc d) M line

a) A band

Which of the following is true about smooth muscle contraction? a) Certain smooth muscle cells can actually divide to increase their numbers. b) Smooth muscle, in contrast to skeletal muscle, cannot synthesize or secrete any connective tissue elements. c) Smooth muscle cannot stretch as much as skeletal muscle. d) Smooth muslce has well-developed T tubules a the site of invagination.

a) Certain smooth muscle cells can actually divide to increase their numbers.

Which of the following statements is most accurate? a) Muscle tension remains relatively constant during isotonic contraction. b) T tubules may be sliding during isotonic contraction. c) The I band lengthens during isotonic contraction. d) Myofilaments slide during isometric contractions.

a) Muscle tension remains relatively constant during isotonic contraction.

What is the functional unit of a skeletal muscle called? a) a sarcromere b) a myofilament c) a myofibril d) the sarcoplasmic reticulum

a) a sarcromere

The sliding filament model of contraction involves ___. a) actin and myosin sliding past each other and partially overlapping b) the shortening of thick filaments so that thin filaments slide past c) actin and myosin shortening but not sliding past each other d) the Z discs sliding over the myofilaments

a) actin and myosin sliding past each other and partially overlapping

In an isotonic contraction, the muscle ___. a) changes in length and moves the "load" b) does not change in length but increases tension c) never converts pyruvate to lactate d) rapidly resynthesizes creatine phosphate and ATP

a) changes in length and moves the "load"

What part of the sarcolemma contains acetylcholine receptors? a) motor end plate b) end of the muscle fiber c) part adjacent to another muscle cell d) any part of the sarcolemma

a) motor end plate

Which of the following is the correct sequence of events for muscle contractions? a) motor neuron action potential, meurotransmitter release, muscle cell action potential, release of calcium ions from SR, AtP-driven power stroke, sliding of myofilaments b) neurotransmitter release, muscle cell action potential, motor reuron action potential, release of calcium ions from SR, sliding of myofilaments, ATP-driven power stroke c) muslce cell action potential, neurotransmitter release, atp-driven power stroke, calcium ion release from SR, sliding of myofilaments d) neurotransmitter rlease, motor neuron cation potential, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke

a) motor neuron action potential, meurotransmitter release, muscle cell action potential, release of calcium ions from SR, AtP-driven power stroke, sliding of myofilaments

What structure in skeletal muscle cells functions in calcium storage? a) sacroplasmic reticulum b) mitochondria c) intermediate filament network d) myofibrillar network

a) sacroplasmic reticulum

Muscle tissue has all of the following properties except ___. a) secretion b) contractility c) extensibility d) excitability

a) secretion

Which of the following are composed of myosin? a) thick filaments b) thin filaments c) all myofilaments d) Z discs

a) thick filaments

Excitation-contraction coupling directly requires which of the following substances? a) ATP only b) Ca2+ and ATP c) ATP and glucose d) Ca2+ only

b) Ca2+ and ATP

Three discrete types of muscle fibers are identified on the basis of their size, speed, and endurance. Which of the following athletic endeavors best represents the use of red fibers? a) a sprint by an Olympic runner b) a long, relaxing swim c) plaoying baseball or basketball d) mountain climbing

b) a long, relaxing swim

The term aponeurosis refers to ___. a) the bands of myofibrils b) a sheetlike indirect attachment to a skeletal element c) the rough endoplasmic reticulum d) the tropomyosin-troponin complex

b) a sheetlike indirect attachment to a skeletal element

During muscle contraction, myosin across bridges attach to which active sites? a) myosin filaments b) actin filaments c) Z discs d) thick filament

b) actin filaments

Which of the following surrounds the individual muscle cells? a) perimysium b) endomysium c) epimysium d) fascicle

b) endomysium

What is the functional role fo theT tubules? a) stabilize the G and F actin b) enhance cellular communication during muscle contraction c) hold cross bridges in place in a resting muscle d) synthesize ATP to provide energy for muscle contraction

b) enhance cellular communication during muscle contraction

An enaerobic metabolic pathway that results in the productionof two net ATPs per glucose plus tow pyruvic acid molecules is ___. a) the citric acid cycle b) glycolysis c) hydrolysis d) the electron transport chain

b) glycolysis

What controls the force of muscle contraction? a) wave summation b) multimotor unit summation c) treppe d) concentric contractions

b) multimotor unit summation

Smooth muscles that act like skeletal muscles but are controlled by autonomic nerves and hormones are ___. a) single-unit muscles b) multiunit muscles c) red muscles d) white muscles

b) multiunit muscles

Of the following muscle types, which has only one nucleus, no sacromeres, and rare gap junctions? a) visceral smooth muscle b) multiunit smooth muscle c) cardiac muscle d) skeletal muscle

b) multiunit smooth muscle

Hypothetically, if a muscle were stretched to the point where thick and thin filaments no longer overalpped, ___. a) cross bridge attachment would be optimum because of all the free binding sites on actin b) no muscle tension could be generated c) maximum for ce production would result because the muscle has a maximum range of travel d) ATP consumption would increase because the sarcomere is "trying" to contract

b) no muscle tension could be generated

When a muscle is unable to respond to stimuli temporarily, it is in which of the following periods? a) relaxation period b) refractory period c) latent period d) fatigue period

b) refractory period

The muscle cell membrane is called the ___. a) endomysium b) sarcolemma c) perimysium d) epimysium

b) sarcolemma

What produces the striations of a skeletal muslce cell? a) a difference in the thickness of the sarcolemma b) the arrangement of myofilaments c) the sarcoplasmic reticulum d) the T tubules

b) the arrangement of myofilaments

What does oxygen deficit reporesent? a) amount of energy needed for exertion b) the difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used. c) the amount of oxygen taken into the body prior to exertion d) the amount of oxygen taken into the body immediately after the exertion

b) the difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used.

Smooth muscle is charaterized by all of the following except ___. a) it appears to lack troponin b) there are more thick filaments than thin filaments c) there are no sarcomeres d) there are noncontractile intermediate filaments taht attach to dense bodies within the cell

b) there are more thick filaments than thin filaments

Which of the following statements is false or incorrect? a) Cardiac muscle contracts when stimulated by its own autorhythmic muscle cells. b) Under normal resting conditions, cardiac muscle tissue contracts and relaxes about 75 times per minute. c) Cardiac muscle fibers depend mostly on anaerobic cellular respiration to generate ATP. d) Cardiac muscle fibers can use lactic acid to make ATP

c) Cardiac muscle fibers depend mostly on anaerobic cellular respiration to generate ATP.

Which of the following statements is true? a) Cardiac muscle cells have many nuclei. b) Smooth muscle cells have T tubules. c) Striated muscle cells are long and cylindrical with many nuclei. d) Cardiac muscle cells are found in the heart and large blood vessels.

c) Striated muscle cells are long and cylindrical with many nuclei.

Muslce tone is ___. a) the ability of a muscle to efficiently cause skeletal movements b) the feeling of well-being following exercise c) a state of sustained partial contraction d) the condition of athletes after intensive training

c) a state of sustained partial contraction

After nervous stimulation stops, what prevents ACh in the synaptic cleft from continuing to stimulate contraction? a) calcium ions returning to the terminal cisternae b) the tropoyosin blocking the myosin once full contraction is achieved c) acetylcholinesterase destroying the ACh d) the actin potential stips going down the overloaded T tubules

c) acetylcholinesterase destroying the ACh

What is the role of calcium ions in muslce contraction? a) form hydoxyapatite cyrstals b) reestablish glycogen stores c) bind to regulatory sites on troponin to remove contraction inhibition d) increase levels of myoglobin

c) bind to regulatory sites on troponin to remove contraction inhibition

Which of the following is "not" a way muscle contractions can be graded? a) changing the frequency of stimulation b) changing the strength of the stimulas c) changing the type of muscle fibers involved in the contraction d) changing the type of neurotransmitter released by the motor neuron

c) changing the type of muscle fibers involved in the contraction

Which of the choices below does "not" describe how recovery oxygen uptake (oxygen deficit) restores metabolic conditions? a) converts lactic acid back into glycogen stores in the liver b) resynthesizes creatine phosphate and ATP in muscle fibers c) increases the level of lactic acid in the muscle d) replaces the oxygen removed from myoglobin

c) increases the level of lactic acid in the muscle

Immediately following the arival of the stimulus at a skeletal muscle cell there is a short period called the ___ period during which the events of excitation-contraction coupling occur. a) contraction b) relaxation c) latent d) refractory

c) latent

Which of the following is a factor that affects the velocity and duration of muscle contraction? a) number of muscle fibers stimulated b) size of the muscle fibers stimulated c) load on the fiber d) muscle length

c) load on the fiber

The oxygen-binding protein found in muscle cells is ___. a) hemoglobin b) ATP c) myoglobin d) immunoglonin

c) myoglobin

Rigor mortis occurs because ___. a) the cells are dead b) sodium oions leak out of the muscle c) no ATP is available to release attached actin and myosin molecules d) proteins are beginning to break down, thus preventing a flow of calcium ions

c) no ATP is available to release attached actin and myosin molecules

Myoglobin ___. a) breaks down glycogen b) is a protein involved in the direct phosphorylation of ADP c) stores oxygen in muscle cells d) produces the end plate protential

c) stores oxygen in muscle cells

The mechanism of contraction in smooth muscle is different from skeletal muscle in that ___. a) actin and myosin interact by the sliding filament mechanism b) the trigger for contraction is a rise in intracellular calcium c) the site of calcium regulation differs d) ATP energizes the sliding process

c) the site of calcium regulation differs

Which of the following describes the cells of single-unit visceral muscle? a) they contract all at once. b) They are chemically coupled to one another by gap junctions. c) they exhibit spontaneous action potentials. d) They consist of muscle fibers that are structurally independent of each other

c) they exhibit spontaneous action potentials.

The warm-up period required of athletes in order to bring their muscles to peak performance is called ___. a) twitch b) wave summation c) treppe d) incomplete tetanus

c) treppe

Which muscle cells have the greatest ability to regenerate? A) skeletal B) cardiac C) smooth D) no muscle can regenerate

c.) Smooth

What is the role of tropomyosin in skeletal muscles? a) Tropomyosin serves as a contraction inhibitor by blocking the actin binding sites on the myosin molecules. b) Tropomyosin is the name of a contracting unit. c) Tropomyosin is the receptor for the motor neuron neurotransmitter. d) Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules.

d) Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules.

Whic of the following is not a role of ionic calcium in muscle contraction? a) triggers neurotransmitter secretion b) promotes contraction inhibitor c) removes contraction inhibitor d) activates epinephrine released from adrenal gland

d) activates epinephrine released from adrenal gland

The main effect of the warm-up period of athletes, as the muscle contractions increase in strenth, is to ___. a) increase the myoglobin content b) convert glycogen to glucose c) tone the muscles and stabilize the joints for the workout d) enhance the availability of calcium and the efficiency of enzyme systems

d) enhance the availability of calcium and the efficiency of enzyme systems

During vigorous exercise, there may be insufficient oxygen available to completely break down pyruvic acid for engery. As a result, the pyruvic acid is converted to ___. a) a strong base b) stearic acid c) hydorchloric acid d) lactic acid

d) lactic acid

he contractile units of skeletal muscles are ___. a) microtubules b) mitochondria c) T tubules d) myofibrils

d) myofibrils

The major function of the sarcoplasmic reticulum in muscle contraction is to ___. a) make and store phosphocreatine b) synthesize actin and myosin myofilaments c) provide a source of myosin for the contraction process d) regulate intracellular calcium concentration

d) regulate intracellular calcium concentration

Creatine phosphate functions in themuscle cell by ___. a) forming a temporary chemical compound with myosin b) forming a chemical compound with actin c) inducing a conformational change in the myofilaments d) storing energy that will be transferred to ADP to resynthesize ATP

d) storing energy that will be transferred to ADP to resynthesize ATP

What is the most distinguishing characteristic of muscle tissue? a) the design of the fibers b) the sarcoplasmic reticulum c) the diversity of activity of muscle tissue d) the ability to transform chemical energy into mechanical energy

d) the ability to transform chemical energy into mechanical energy