Chapter 10 & 12 A&P

The net energy yield from one glucose molecule through the process of glycolysis is:

! 2 ATP. 6 ATP. 34 ATP. 36 ATP

Each thick filament contains about ______ protein molecules (each molecule has two heads and two braided tails).

! 200

This sarcomere depicts relaxed muscle. Number 1 denotes the

! A band H zone Z disc M line I band

Somatic motor neuron axons fall into the category of:

! A fibers. B fibers. C fibers. D fibers.

Which occurs first?

! Absolute refractory period Relative refractory period

The top long distance runners probably have _______ proportion of slow muscle fibers in their leg muscles.

! a higher a lower the same

A graph of an EPSP would plot time against a voltage trace that would resemble:

! a hill where the high point approaches the threshold value. a hill where the high point is the farthest away from the threshold value. a valley where the low point approaches the threshold value. a valley where the low point is the farthest away from the threshold value

Conductive activity in a neuron generally causes it to secrete:

! a specific neurotransmitter that either excites or inhibits its target. a specific neurotransmitter that always excites its target. several types of neurotransmitter simultaneously, all of which excite the cell's target. several types of neurotransmitter simultaneously, that are broadcast to excite and inhibit multiple targets. several types of neurotransmitters simultaneously, that all work to prevent another immediate impulse

Based on structure, the most common type of neuron is the _______ neuron.

! multipolar bipolar unipolar pseudounipolar

A depolarization is when the inside of a neuron becomes _______________ the resting membrane potential.

more negative than → less negative than closer to

The afferent division of the nervous system is also known as the _____ division.

motor cranial ganglial efferent → sensory

This sarcomere depicts relaxed muscle. The M line is noted by number

1 3 → 4 5

For relaxation to occur:

! Ach receptors close and Ca++ channels on the sarcoplasmic reticulum close. Ach receptors close and Ca++ channels on the sarcoplasmic reticulum open. Ach receptors open and Ca++ channels on the sarcoplasmic reticulum close. Ach receptors open and Ca++ channels on the sarcoplasmic reticulum open.

Which of the myofilaments of a muscle fiber has the active sites to which the heads of the thick filaments will bind?

! Actin Troponin Tropomyosin Myosin Sarcoplasm

What is the most abundant glial cell in the CNS?

! Astrocyte Ependymal cell Neurolemmocyte Microglial cell Oligodendrocyte

Where are synaptic knobs located?

! At the tips of telodendria At the ends of dendrites Within the cell body Along axon collaterals At the axon hillock

Which sequence correctly lists the changes that allow the thick and thin filaments to slide past one another in skeletal muscle contraction?

! Attach - pivot - detach - return Pivot - attach - return - detach Attach - detach - pivot - return Return - pivot - attach - detach Pivot - attach - detach - return

When a neurotransmitter opens a chemically gated ion channel that allows sodium to enter the postsynaptic cell, the result is an:

! EPSP. IPSP.

Which statement is true regarding the action of an oligodendrocyte?

! Each oligodendrocyte can form a myelin sheath around many axons simultaneously. An oligodendrocyte is responsible for forming part of the blood-brain barrier. Oligodendrocytes function only within the PNS. Each oligodendrocyte can wrap only a 1 mm portion of a single axon. A neurolemmocyte attacks pathogens

Which is not characteristic of neurons?

! High mitotic rate High metabolic rate Require continuous supplies of glucose and oxygen Extreme longevity No exceptions; all of these are characteristic of neurons

Which letter is associated with the light band and contains thin filaments only?

! I A M Z H

Which contraction occurs when you try (unsuccessfully) to move a wall?

! Isometric Isotonic

Which protein makes up the thick filaments?

! Myosin Actin Tropomyosin Troponin Myopathy

Which fibers dominate many of the back and calf muscles that contract almost continually to maintain posture?

! Slow Fast Intermediate

Which structures are reservoirs that store acetylcholine?

! Synaptic vesicles Synaptic clefts Terminal cisternae Lysosomes Sarcomeres

Invaginations of the muscle cell membrane that extend deep into the cell are known as the:

! T-tubules. terminal cisternae. titin complexes. Z-discs. end plates.

Which statement accurately compares the transmission speed of the different types of synapses.

! Transmission at chemical synapses involves a brief synaptic delay, but electrical synapses are faster. Transmission at both chemical and electrical synapses involve a synaptic delay of approximately 1 millisecond. Transmission at electrical synapses involves a brief synaptic delay, but chemical synapses are faster. Electrical synapses have a constant delay of 1 millisecond, but chemical synaptic delays vary between 0.1 and 0.3 millisecond.

Which is not a general function of the nervous system?

! Transporting materials throughout the body Collecting information Processing and evaluating information Responding to information No exceptions; all are general functions of the nervous system

A sarcomere is defined as the distance from one _____ to the next adjacent ____ . (The same answer fills in both spaces.)

! Z disc I band H zone A band M line

With increased age, skeletal muscles show:

! a decrease in the number of myofibrils. an increase in muscle fiber diameter. no change in oxygen storage capability. increased glycogen reserves. a tendency to fatigue less rapidly.

Which is a correct listing of the hierarchy of a skeletal muscle's components, beginning with the smallest? a: Myofibrils b: Muscle fiber c: Fascicle d: Skeletal muscle

! a, b, c, d a, c, b, d d, c, b, a c, b, a, d b, c, a, d

The presence of mitochondria and myoglobin facilitate _________ respiration in muscle cells.

! aerobic anaerobic

A flat, thin structure made of dense connective tissue that serves to attach a muscle to a bone (or to another muscle) is a(n):

! aponeurosis. tendon. perimysium. myolemma. superficial fascia.

The glial cell that helps to form the blood-brain barrier is the:

! astrocyte. ependymal cell. neurolemmocyte. microglial cell. oligodendrocyte

The glial cell that provides structural support and organization to the CNS is the:

! astrocyte. ependymal cell. neurolemmocyte. microglial cell. oligodendrocyte

The glial cell with perivascular feet that wrap around capillaries in the CNS is the:

! astrocyte. ependymal cell. neurolemmocyte. microglial cell. oligodendrocyte

The glial cell with the responsibility of occupying the space left by dead or dying neurons is the:

! astrocyte. ependymal cell. neurolemmocyte. microglial cell. oligodendrocyte.

The branch of the nervous system that helps govern smooth muscle contraction is the _______ nervous system.

! autonomic somatic

A neuron conducting an impulse from the CNS to the detrusor muscle of the urinary bladder would be classified as a(n) __________ neuron.

! autonomic motor somatic sensory somatic motor visceral sensory

The conductive segment of a neuron is its _______, a region that contains many _______ gated channels.

! axon, voltage- axon, chemically dendrite, voltage- dendrite, chemically

The type of transport protein that moves a substance down its concentration gradient is a:

! channel. pump

The type of neuronal circuit in which several nerve impulses come together at a single postsynaptic neuron is a _____________ circuit.

! converging diverging reverberating parallel-after-discharge None of the choices is correct

You walk into a restaurant and amidst the sights, sounds, and smells of food preparation, you notice that you have begun to salivate. This is evidence that a particular neuronal circuit has been activated. Which one?

! converging diverging reverberating parallel-after-discharge None of the choices is correct

The main way acetylcholine is cleared from a synapse is by:

! degradation by an enzyme. uptake by the postsynaptic cell. reuptake by the presynaptic cell. being engulfed by a supporting glial cell.

Hyperpolarization of a neuron results from:

! either the entry of an anion or the exit of a cation. the entry of any ion. either the entry of a cation or the exit of an anion. the entrance of either sodium or potassium.

When a neuromodulator slows the reuptake of a neurotransmitter or causes expression of an increased number of receptors on postsynaptic neurons, the effect is called:

! facilitation. temporal summation. spatial summation. presynaptic potentiation. recruitment

Vesicles and glycoproteins required at the synapse are moved down a nerve fiber by _______ axonal transport.

! fast

Muscles of the eye and hand have a high percentage of _______ fibers.

! fast slow

The multiple nuclei in skeletal muscle cells are the result of the:

! fusion of myoblasts. cytokinesis of embryonic satellite cells. spontaneous development of nuclei in embryonic cells. stimulation of fibroblasts by hormones. action of testosterone on mesenchyme cell.

Muscle tone is a result of _________ nervous system activity, and it acts to _________ joint position.

! involuntary, stabilize involuntary, continuously vary voluntary, stabilize voluntary, continuously vary

The vascular supply to slow muscle fibers is ______ the network of capillaries around fast muscle fibers.

! more extensive than less extensive than the same as that of

If there were no sodium leak channels, the resting membrane potential of a neuron would be:

! more negative. more positive. the same. 0 mV.

Saltatory conduction occurs in:

! myelinated axons, where action potentials occur only at neurofibril nodes. myelinated axons, where action potentials occur only under the myelin sheath. myelinated axons, where action potentials occur continuously down the entire axon. unmyelinated axons, where action potentials occur continuously down the entire axon. the axon terminal, where full size action potentials occur at the hillock.

A skeletal muscle cell contains hundreds to thousands of _________, which are complex organelles; they are cylindrical in shape--about 2 micrometers in diameter and as long as the cell.

! myofibrils microfilaments sarcomeres T-tubules sarcolemma

Arrival of an action potential at the synaptic knob results in:

! opening of voltage-gated calcium channels and diffusion of calcium into the synaptic knob. opening of voltage-gated calcium channels and diffusion of calcium out of the synaptic knob to the interstitial fluid. closure of voltage-gated calcium channels in the synaptic knob membrane. opening of chemically gated calcium channels and diffusion of calcium into the synaptic knob. opening of chemically gated calcium channels and diffusion of calcium out of the synaptic knob to the interstitial fluid

When voltage-gated K+ channels open on the conductive segment of a neuron:

! potassium exits, repolarizing the cell to a negative value. potassium exits, depolarizing the cell to an even more negative value. potassium enters, depolarizing the cell to a positive value. potassium enters, repolarizing the cell to a negative value. potassium enters, repolarizing the cell to a positive value.

The most crucial factor determining the resting potential of a neuron is the diffusion of:

! potassium out of the cell through leak channels. potassium into the cell through gated channels. sodium out of the cell through leak channels. sodium into the cell through gated channels

Consider the difference between lifting a light pad of paper versus a heavy text book. The primary way the level of force of muscle contraction is controlled is by:

! recruiting a different number of motor units. activating different regions of the muscle. activating the motor units at a different frequency. altering the number of crossbridges each individual fiber uses.

The increase in muscle tension that occurs with an increase in the intensity (voltage) of a stimulus is called:

! recruitment. treppe. wave summation. incomplete tetany

Oxidative fibers are:

! red and fatigue-resistant. red and fatigable. white and fatigue-resistant. white and fatigable

The glial cell that protects neuron cell bodies located within ganglia is the:

! satellite cell. ependymal cell. neurolemmocyte. astrocyte. oligodendrocyte.

The most abundant form of smooth muscle is:

! single-unit, which is also known as visceral smooth muscle. cardiac muscle, which is also known as visceral smooth muscle. multiunit, which is also known as visceral smooth muscle. multiunit, which is also known as varicose muscle. single-unit, which is also known as somatic nervous system muscle

In a mixed nerve:

! some axons transmit sensory information and others transmit motor information. individual axons transmit both sensory and motor information. chemical synapses occur along with electrical synapses. astrocytes are interspersed with ependymal cells

The glossy-white appearance of most axons is due to:

! the high lipid content of the myelin sheath. their proximity to light-reflecting cartilage. their proximity to white bone. the white color of the perivascular feet. the covering of ependymal cells.

When transmission occurs at a synapse, neurotransmitter is released by:

! the presynaptic neuron's synaptic knob into the synaptic cleft. the postsynaptic neuron's dendrites into the synaptic cleft. the presynaptic neuron's dendrites into the synaptic cleft. the presynaptic neuron's soma into synaptic vesicles. the postsynaptic neuron's telodendria into the axon hillock.

Wallerian degeneration involves the breakdown of:

! the segments of axon and myelin sheath between the site of damage and the peripheral effector. the segments of axon and myelin sheath between the site of damage and the cell body. the neurilemma both central and peripheral to the site of trauma. macrophages and microglia that have completed the job of CNS cleanup after trauma

Action potentials are generated by the opening of ________ gated channels and they occur on the ________.

! voltage-, axon voltage-, dendrite chemically, axon chemically, dendrite

A typical skeletal muscle cell contains approximately _____ mitochondria.

3 30 → 300 3000

The slowest category of nerve fibers are the:

A fibers, and they conduct impulses at 10 meters per second. → C fibers, and they conduct impulses at 1 meter per second. D fibers, and they conduct impulses at 0.1 meter per second. C fibers, and they conduct impulses at 100 meters per second. D fibers, and they conduct impulses at 0.01 meter per second

Typically, the resting membrane potential of a neuron is:

7 V. 700 mV. −7 V. → −70 mV. 0 mV.

Which is the neurotransmitter that causes the release of calcium ions from reservoirs within the muscle cell and thereby initiates the steps of contraction?

Acetylcholinesterase Rubitussin → Acetylcholine Serotonin Norepinephrine

The primary inhibitory neurotransmitter in the brain is:

glutamate. valine. → GABA. serotonin. serine

Fibers from one motor unit:

are clustered together within one fascicle of the muscle. → are dispersed throughout most of the muscle.

Which statement is consistent with the current understanding of neural tissue?

A person is born with all of the neurons they will ever have. → Most neurons formed in fetal development last a lifetime, but some brain regions in adults can generate new neurons. Neurons are constantly dying and being replaced throughout all regions of the brain. Stem cells in the brain become glia, which can later become neurons if there is a need for them to do so.

Which is not a protein found in thin filaments?

Actin Troponin Tropomyosin → Sarcomyosin No exceptions; all are found in thin filaments

Which functional class of neurons lies entirely within the central nervous system?

Bipolar neurons Sensory neurons → Interneurons Unipolar neurons Motor neurons

Which division of the nervous system shows a greater capacity for regeneration?

CNS → PNS

Of the two types of synapses, based on mode of communication, which is less common but allows faster signal transmission?

Chemical synapse Mechanical synapse Physical synapse Magnetic synapse → Electrical synapse

Which is not a function of the motor division of the nervous system?

Conducts impulses from the CNS Transmits impulses to muscles and glands → Transmits impulses from the viscera Voluntary control of skeletal muscle Involuntary control of the heart

Which is not a type of neuronal pool?

Converging → Triangular-pre-discharge Diverging Parallel-after-discharge Reverberating

Which part of the neuron contains the nucleus?

Dendrite Axon → Soma Axon hillock Telodendrion

When a neurotransmitter causes the opening of chemically gated potassium channels on the postsynaptic cell, the postsynaptic potential that results is an:

EPSP, which is a depolarization. EPSP, which is a hyperpolarization IPSP, which is a depolarization. → IPSP, which is a hyperpolarization.

Which is true regarding the action of a neurolemmocyte?

Each neurolemmocyte can form a myelin sheath around many axons simultaneously. A neurolemmocyte is responsible for forming part of the blood-brain barrier. Neurolemmocytes function only within the CNS. → Each neurolemmocyte can wrap only a 1 mm portion of a single axon. A neurolemmocyte attacks pathogens

Which letter is associated with the line that is a thin protein structure that serves as an attachment site for thin filament ends?

I A → Z M H

Which letter is associated with a zone (in a relaxed muscle) that is a little more lightly shaded because only thick filaments are present?

I A M Z → H

What is the letter associated with the dark bands in a sarcomere?

I → A Z M H

During which phase of the crossbridge cycle is ATP split into ADP and Pi?

Immediately preceding the detachment of the myosin head → Immediately preceding the resetting of the myosin head Immediately preceding the power stroke

There are two types of synapses, based on mode of communication. What are they?

Mechanical and chemical Magnetic and physical Physical and chemical → Chemical and electrical Mechanical and electrical

What structures extend into the axon and dendrite of a neuron to provide tensile strength?

Motor filaments Nissl bodies Telodendria → Neurofibrils Collateral fibers

Which choice correctly orders the connective tissue wrappings of a nerve, beginning at the outermost layer?

Perineurium → epineurium→ endoneurium Perineurium → endoneurium→ epineurium → Epineurium → perineurium→ endoneurium Epineurium → endoneurium→ perineurium Endoneurium → perineurium→ epineurium

Which may occur as a result of muscle atrophy?

Reduction in muscle size Fibers become weaker Muscle loses tone Fibers waste away and die → All choices are correct

Which are the reservoirs that store the calcium required for muscle contraction?

Synaptic vesicles Synaptic clefts → Terminal cisternae Peroxisomes Mitochondria

What do all glial cells have in common?

They help to transmit the nerve signals. They transfer blood to the various neurons. → They assist neurons in their respective functions. They all attack pathogens. They absorb extra blood and cerebrospinal fluid

A drug that inhibited acetylcholinesterase would result in:

a failure to stimulate the muscle due to decreased Ach release. → enhanced stimulation of the muscle due to decreased Ach breakdown. enhanced stimulation of the muscle due to enhanced Ach release. poor muscle stimulation due to enhanced Ach breakdown

Which is the correct order of the connective tissue layers of a skeletal muscle, beginning with the outermost first? a: Endomysium b: Epimysium c: Perimysium

a, b, c b, a, c c, a, b → b, c, a c, b, a

In general, a skeletal muscle is composed of :a: connective tissue sheaths b: nerves c: arteries d: veinse: muscle fibers

a, b, c, e a, b, d, e b, c, d, e a, b, c, d → a, b, c, d, e

Which are possible functions of skeletal muscles?a: Maintenance of postureb: Both highly coordinated and localized simple movementsc: Temperature regulationd: Support of certain body organse: Regulation of the movement of material through certain body tracts

a, b, e a, b, c a, b, c, e a, b, c, d → a, b, c, d, e

Choose the answer that correctly lists, in chronological order, the events involved in synaptic transmission. a: A nerve impulse reaches the synaptic knob. b: Neurotransmitter molecules diffuse across the synaptic cleft. c: A nerve impulse begins in the postsynaptic cell. d: Neurotransmitter molecules bind to receptors in the postsynaptic cell. e: A voltage change occurs in the postsynaptic cell

a, c, b, d, e a, b, e, d, c c, b, d, e, a → a, b, d, e, c c, a, b, d, e

Catecholamines are a subtype of __________ neurotransmitter.

acetylcholine neuropeptide → monoamine amino acid soluble gas

In neurophysiology, the term summation refers to the addition of:

action potentials at the node of Ranvier. → postsynaptic potentials at the initial segment. excitatory neurotransmitter molecules at a receptor. resting membrane potentials in a particular area of the brain. presynaptic hyperpolarizations

Glycolysis is an:

aerobic process that occurs in the cytosol. aerobic process that occurs in the mitochondria. → anaerobic process that occurs in the cytosol. anaerobic process that occurs in the mitochondria

For a sprint lasting 60 seconds, ATP is supplied initially by:

aerobic respiration but eventually by anaerobic respiration. → the phosphagen system but primarily by glycolysis. myokinase but primarily by creatine kinase. the phosphagen system but primarily by aerobic respiration. oxidative phosphorylation, but eventually by the phosphagen system.

The nervous system controls the activity of muscles and glands. Muscles and glands can generate changes and are therefore called:

afferents. → effectors. stimuli. visceral.

A power stroke involves:

an actin molecule pulling a myosin molecule toward the M-line. a thin filament shortening in length and thereby shortening the sarcomere. → a myosin head pulling a thin filament toward the center of the sarcomere. a thick filament pushing an actin filament towards the nearest Z-line.

Glial cells differ from neurons in that they:

are larger and capable of meiosis. → are smaller and capable of mitosis. are found only in the CNS. are found only in the PNS. transmit nerve impulses much more slowly

The glial cell that myelinates and insulates axons within the CNS is the:

astrocyte. ependymal cell. neurolemmocyte. microglial cell. → oligodendrocyte.

The glial cell that defends the body against pathogens is the:

astrocyte. ependymal cell. neurolemmocyte. → microglial cell. oligodendrocyte.

The glial cell that myelinates and insulates axons in the peripheral nervous system is the:

astrocyte. ependymal cell. → neurolemmocyte. microglial cell. oligodendrocyte

The glial cell that helps to circulate cerebrospinal fluid is the:

astrocyte. → ependymal cell. neurolemmocyte. microglial cell. oligodendrocyte.

The action potential of a muscle fiber occurs:

at the end plate. → along the sarcolemma and down the T-tubules. within the sarcoplasmic reticulum. in the mitochondria.

A neuron conducting an impulse from the stomach wall to the CNS would be classified as a(n) __________ neuron.

autonomic motor somatic sensory somatic motor → visceral sensory

The portion of the nervous system that has voluntary control over skeletal muscles is the _____________ division.

autonomic motor somatic sensory → somatic motor visceral sensory

The portion of the nervous system that conducts impulses from the skin, joints, skeletal muscles, and special senses is the ___________ division.

autonomic motor → somatic sensory somatic motor visceral sensory

The function of myelin is to:

block the transmission of a nerve impulse. provide points of attachment for nerve threads. → produce faster nerve impulse propagation. produce slow but continuous impulse conduction.

The way acetylcholine is released from a neuron is:

by a primary active transport pump. by rapid diffusion when a voltage-gated ion channel opens for it. → through exocytosis when a vesicle fuses with the membrane. by conduction through a gap junction from nerve to muscle.

The main way a body builder's muscles become larger is:

by an increase in the number of muscle cells. → by an increase in the size of muscle cells.

When a nerve impulse reaches the transmissive segment of a neuron:

calcium is pumped into the neuron and neurotransmitter diffuses out through channels. calcium is released from the neuron along with neurotransmitter from synaptic vesicles. → calcium diffuses into the neuron and neurotransmitter is released by exocytosis. calcium and neurotransmitter diffuse into the synaptic knob. calcium is immediately pumped out of the neuron and vesicles of neurotransmitter undergo phagocytosis

One feature that helps provide fast energy to a muscle cell is the presence of granules containing the complex carbohydrate:

creatine phosphate. myoglobin. → glycogen. nebulin. hemoglobin.

For relaxation to occur:

calcium leaves the sarcoplasmic reticulum, troponin binds calcium and blocks the binding sites on actin. calcium enters the myofibril, it detaches from myosin, and the binding sites on myosin become inactive. → sarcoplasm calcium levels fall, calcium is removed from troponin, and tropomyosin blocks binding sites on actin. extracellular calcium levels fall, calcium is pumped into the myofibril, and tropomyosin slides away from actin.

Increased phosphate ion concentration is believed to contribute to fatigue by interfering with:

calcium release from the sarcoplasmic reticulum. levels of available ATP to provide energy for contraction. → phosphate release by myosin heads during crossbridge cycling. Ach release by synaptic knobs of motor neurons

The latchbridge mechanism of myosin heads is a property of ________ muscle.

cardiac skeletal → smooth

Nerves and ganglia are structures found in the:

central nervous system. → peripheral nervous system. both the central and peripheral nervous systems.

The repolarization of the action potential involves the opening of:

chemically gated Na+ channels. voltage-gated Na+ channels. chemically gated K+ channels. → voltage-gated K+ channels.

The characteristic of muscle that allows it to be passively stretched is:

conductivity. elasticity. excitability. → extensibility. contractility.

A motor unit within the powerful quadriceps muscle would:

contain several motor neurons. be much like those in the eye muscles. generally contain less than ten fibers. → generally contain several hundred fibers.

A nerve:

contains a single axon. is found only in the CNS. carries only sensory information. carries information only toward the PNS. → is a cablelike bundle of parallel axons

When smooth muscle is stretched for a prolonged period of time, it responds by:

contracting. → relaxing

Release of crossbridges and a decline in muscle tension characterize the _______ period of a twitch.

contraction latent → relaxation

The type of neuronal circuit in which several neurons process the same information at one time is a _____________ circuit.

converging diverging reverberating → parallel-after-discharge None of the choices is correct

What type of circuit would you use to solve a higher-order mathematical problem?

converging diverging reverberating → parallel-after-discharge None of the choices is correct

The type of neuronal circuit that ensures that we continue to breathe while asleep is a _____________ circuit.

converging diverging → reverberating parallel-after-discharge None of the choices is correct

The type of neuronal circuit that uses feedback to produce a repeated, cyclical stimulation of the circuit is a _____________ circuit.

converging diverging → reverberating parallel-after-discharge None of the choices is correct

The type of neuronal circuit that spreads information from one presynaptic neuron to several postsynaptic neurons is a _____________ circuit.

converging → diverging reverberating parallel-after-discharge None of the choices is correct

What type of circuit is used to maintain body posture while walking?

converging → diverging reverberating parallel-after-discharge None of the choices is correct

A mixed nerve refers to one that contains both:

cranial and spinal nerve fibers. → sensory and motor neurons. unipolar and bipolar neurons. an endoneurium and an epineurium. presynaptic and postsynaptic neurons

Myoglobin is a molecule within muscle cells that can bind:

creatine phosphate. → oxygen. hemoglobin. acetylcholine. ATP

When a muscle relaxes:

crossbridges form and muscle extensibility returns the muscle to rest length. crossbridges form and muscle elasticity returns the muscle to rest length. → crossbridges stop forming and muscle elasticity returns the muscle to rest length. crossbridges stop forming and muscle extensibility returns the muscle to rest length

The separation of oppositely charged ionic particles across a resting neuron's membrane results in a potential that is measured as a:

current. → voltage. conductance. resistance

The endoneurium is composed of:

dense regular connective tissue. simple squamous epithelium. dense irregular connective tissue. → areolar connective tissue. pseudostratified nonkeratinized epithelium.

The epineurium is composed of:

dense regular connective tissue. simple squamous epithelium. → dense irregular connective tissue. areolar connective tissue. pseudostratified nonkeratinized epithelium

When a muscle is isometrically contracted, its length _______ change.

does → does not

The monoamine that has functions related to sleep, appetite, cognition, and mood is:

dopamine. → serotonin. norepinephrine. acetylcholine. epinephrine

A skeletal muscle cell can be several inches long. The property of muscle tissue that allows an impulse to travel down the entire length of the cell membrane is:

elasticity. → conductivity. extensibility. contractility. responsibility.

One of the ways that neurotransmitter is removed from the synaptic cleft is:

endocytosis by the postsynaptic cell. → reuptake by the presynaptic cell. phagocytosis by a macrophage. dendritic lassos.

When an impulse arrives at the knob of the motor neuron, calcium:

enters through active transport pumps and triggers the release of transmitter. → enters through voltage-gated channels and triggers the release of transmitter. exits through active transport pumps and brings transmitter with it. exits through voltage-gated channels and triggers transmitter release. is released from synaptic vesicles.

The connective tissue wrapping that surrounds bundles (fascicles) of axons is the:

epineurium. endoneurium. → perineurium. endosteum. periosteum.

The spring-like property that returns muscle to its original length after a contraction ends is:

extensibility. → elasticity. contractility. treppe effect. conductivity.

The type of fibers specialized to continue contracting for extended periods of time, as would be required in running a marathon, for example, are _____ fibers.

fast → slow intermediate

"Intermediate fibers" is another name for:

fast, glycolytic fibers. → fast, oxidative fibers. slow, glycolytic fibers. slow, oxidative fibers

Rather than tightly coupled synapses between neurons and muscle cells, single-unit smooth muscle contains:

gap junctions that connect neurons to smooth muscle cells. varicosities of a subset of muscle fibers so that individual cells can be separately stimulated. → diffuse junctions where neuron varicosities are responsible for neurotransmitter release. plaques and caveolae that contain multiple hormone receptors for discrete endocrine control

Neural stem cells in the CNS:

have no known function. can only form glial cells. can form new neurons throughout the CNS. → can form new neurons in only certain portions of the CNS such as the hippocampus. can migrate to the PNS as needed.

The phosphagen system is used for:

immediate ATP needs and is dependent on oxygen. → immediate ATP needs and is not dependent on oxygen. long term ATP needs and is dependent on oxygen. long term ATP needs and is not dependent on the presence of oxygen.

One of the reasons you might struggle to lift a heavy object if you tried to lift it with your arm at a fully extended posture is that:

in extension, the proximity of Z discs to thick filaments restricts the sliding movement within sarcomeres. → full extension results in decreased overlap between thick and thin filaments in the muscle. in that posture, some myosin heads overlap actin in the wrong orientation and tug actin in the wrong direction. motor neurons cannot release as much Ach in that posture

With damage to nerve fibers, larger distances between the site of damage and the target structure innervated result in _________ chances of successful regeneration.

increased → decreased

Chemically gated ion channels are mainly found in the ________ segment of a neuron.

initial → receptive conductive transmissive

Receptors are parts of the nervous system that allow it to:

initiate responses to information. process information. → collect information. conduct impulses to muscles.

Potassium has a higher concentration:

inside the cell versus outside the cell, and sodium is also more concentrated inside versus outside the cell. → inside the cell versus outside the cell, whereas sodium has a higher concentration outside versus inside the cell. outside the cell versus inside the cell, and sodium is also more concentrated outside versus inside the cell. outside the cell versus inside the cell, whereas sodium has a higher concentration inside versus outside the cell.

In a lab, wave summation is demonstrated by increasing the _________ of the stimulus.

intensity → frequency capacitance warm up time

A graded potential is one that:

is all or none (always the same intensity). travels the length of the nerve fiber (is long distance). → varies in size depending on the magnitude of the stimulus (larger voltage change for stronger stimulus). lasts for several seconds after ion channels have opened, closed, and reset

The narrow space that separates the motor neuron and the skeletal muscle fiber in a neuromuscular junction is called the:

motor end plate. synaptic vesicle. → synaptic cleft. synaptic knob. Ach floor.

A motor unit consists of:

multiple motor neurons and multiple muscle fibers. → a single motor neuron and the multiple muscle fibers it controls. multiple motor neurons and the one muscle fiber they control. one synaptic terminal button, a cleft, and an acetylcholine receptor. an end plate, T-tubule, and sarcoplasmic reticulum.

The iris of the eye contains:

multiunit smooth muscle????

Continuous conduction of a nerve impulse occurs only along:

myelinated axons. dendrites. → unmyelinated axons. axons in the PNS. axons in the CNS

In a myelinated axon, the greatest concentration of voltage-gated ion channels is in the:

myelinated regions. → neurofibril nodes.

A nerve impulse travels fastest along ________ axons of ______ diameter.

myelinated, small unmyelinated, small → myelinated, large unmyelinated, large

The calcium ions involved in skeletal muscle contraction bind to a(n)______ subunit.

myosin actin elastin tropomyosin → troponin

Growth of the uterus during pregnancy is accomplished by _________ of its smooth muscle.

neither hypertrophy nor hyperplasia → both hypertrophy and hyperplasia hypertrophy but not hyperplasia hyperplasia but not hypertrophy

Billions of CNS interneurons are grouped in complex patterns called neuronal:

networks. complexes. → pools. meshes. webs.

The hyperpolarization that occurs at the end of an action potential is due to the prolonged:

open state of voltage-gated sodium channels. closure of chemically gated sodium channels. → open state of voltage-gated potassium channels. closure of voltage-gated potassium channels. open state of chemically gated sodium channels.

Fast axonal transport is:

passive and only occurs in the anterograde direction. passive and only occurs in the retrograde direction. active (requires ATP) and only occurs in the anterograde direction. active (requires ATP) and only occurs in the retrograde direction. → active (requires ATP) and can occur in either the anterograde or retrograde direction.

An end plate potential is an event that involves a gain of:

positive charge for the cell, as potassium rapidly enters. → positive charge for the cell, as sodium rapidly enters. negative charge for the cell, as potassium rapidly enters. negative charge for the cell, as sodium rapidly enters

Most commonly, a synapse is made between a:

presynaptic neuron's dendrite and a postsynaptic membrane's cell body. → presynaptic neuron's axon and a postsynaptic neuron's dendrite. presynaptic neuron's axon hillock and a postsynaptic neuron's cell body. presynaptic neuron's soma and a postsynaptic neuron's synaptic knob.

A term that describes the change in muscle following a lack of exercise is:

proliferation. hypertrophy. convergence. → atrophy. myofascia

Events of excitation contraction coupling, such as the release of calcium from intracellular stores, occur during the ________ period of a muscle twitch.

relaxation contraction → latent

As a neuron's refractory period ends, its sodium channels are changing from:

resting state to their inactivated state. → their inactivated state to their resting state. their resting state to their activated state. their activated state to their resting state.

The membranous network that wraps around myofibrils and holds relatively high concentrations of calcium is known as the:

sarcolemma. T-tubule. → sarcoplasmic reticulum. sarcomere. Golgi body

Following damage to axons nearby, oligodendrocytes:

secrete growth factors. do not secrete any chemicals. → secrete growth-inhibitory molecules. grow their own fibers to occupy the space.

The neurons that stimulate muscle contraction are called _____ neurons

sensory contractile inhibitory → motor association

The neurons that are responsible for integrating information by retrieving, processing, storing, and "deciding" how the body responds to stimuli are:

sensory neurons. motor neurons. accessory neurons. correlation neurons. → interneurons

Based on function, 99 percent of neurons are:

sensory neurons. motor neurons. unipolar neurons. bipolar neurons. → interneurons.

Smooth muscle tissue in which cells are individually sent signals to contract (rather than contracting in unison) is referred to as:

single-unit. → multiunit.

The type of muscle fibers that have only a single nucleus, both thick and thin filaments, but no Z discs, are:

skeletal. cardiac. → smooth. cardiac and smooth. cardiac and skeletal.

The type of muscle fibers that are striated, form Y-shaped branches, and have junctions called intercalated discs are:

skeletal. → cardiac. smooth. voluntary. skeletal and voluntary.

The most prevalent of skeletal muscle fibers in the body are _____ fibers.

slow → fast intermediate

The cytoplasm within a cell body of a neuron is called the:

soma. → perikaryon. neurokaryon. chromatophilic substance. chromatophobic substance

The structure responsible for attaching muscle to bone is a:

sphincter. ligament. fascia. → tendon. myofibril.

Acetylcholine exerts its effect by:

stimulating the motor neuron's synaptic knob. → binding to receptors at the motor end plate. activating acetylcholinesterase. allowing calcium to enter the cell.

When multiple presynaptic neurons release neurotransmitter at various locations onto the postsynaptic neuron at the same time it results in:

suprathreshold hyperpolarization. temporal summation. → spatial summation. several action potentials.

Electrical synapses involve coupling of neurons by:

synaptic clefts. desmosomes. → gap junctions. satellite cells

As an axon approaches the cell onto which it will terminate, it generally branches repeatedly into several:

teloaxons. dendrites. collateral axons. → telodendria. neurolemmocytes.

The electrochemical gradient refers to:

the difference in concentration of a substance between two areas. the difference in electrical charge between two areas. → the combination of electrical and chemical gradients between two areas. the resistance a membrane has to allowing any charged chemical to pass through it.

To initiate a smooth muscle cell contraction, calcium enters the cell and binds to:

troponin, which then activates myosin light chain kinase. → calmodulin, which then binds to and activates myosin light chain kinase. a myosin head, which then activates calmodulin. myosin light chain kinase, which then hydrolyzes ATP. a phosphatase, which then removes the tropomyosin blockade

A bipolar neurons has:

two axons extending from the cell body. two dendrites extending from the cell body. → one axon and one dendrite extending from the cell body. a single short process that extends from the cell body and then splits into a peripheral and central branch.

To measure the resting potential of a neuron, a physiologist would place:

two electrodes inside the neuron. → one microelecrode inside the neuron and another in the interstitial fluid. one electrode inside the cell and another inside another cell. one electrode inside the cell and another outside the body

Maintenance of appropriate ion concentrations (especially after nerve impulses that involved ion diffusion) is primarily the job of:

voltage-gated channels. → sodium-potassium pumps. chemically gated channels. mechanically gated channels

The type of voltage-gated channel that possesses an inactivation gate that temporarily closes after the channel is active is the:

voltage-gated potassium channel. → voltage-gated sodium channel. voltage-gated calcium channel. voltage-gated chloride channel

"Staircase" and "warm up" are alternative names for ___________, an increased muscle response to a constant stimulus.

wave summation → treppe multiple motor unit summation incomplete tetany isotony