Neurobiology textbook Questions

VET30360

CH 3, Q1: which part of a neuron is primarily characterized as the information-receiving component?

a. axon

b. presynaptic terminal

c. cell body

d. dendrite

e. myelin

d. dendrite

CH 3, Q2: which of the following is not characteristic of glial cells?

a. production of action potentials

b. immune responses of the nervous system

c. production of the myelin sheaths of axons

d. modulating the growth of developing or damaged neurons

e. buffering extracellular concentrations of some ions and neurotransmitters

a. production of action potentials

CH 3, Q3: the elements of spinal and cranial nerves that carry action potential commands from the CNS to synapses at skeletal muscles are

a. axons of visceral efferent neurons

b. axons of somatic afferent neurons

c. axons of somatic efferent neurons

d. the dorsal roots

e. axons of visceral afferent neurons

c. axons of somatic efferent neurons

CH 3, Q4: the thalamus and hypothalamus are components of which major brain division?

a. medulla

b. pons

c. midbrain

d. diencephalon

e. telencephalon

d. diencephalon

CH 4, Q1: when treating critically ill patients with intravenous fluids, which two ions are most important to the neuronal membrane potential?

a. Na+ and Cl-

b. K+ and Cl-

c. Ca2+ and Cl-

d. K+ and Ca2+

e. Na+ and K+

e. Na+ and K+

CH 4, Q2: the energy required by the Na+, K+ neural membrane pump is derived from ATP. in the neuron, this energy results from the nearly exclusive metabolism of oxygen and:

a. amino acids

b. fatty acids

c. glucose

d. glycogen

e. proteins

c. glucose

CH 4, Q3: if the number of IPSPs on the dendritic membrane decreases while the number of EPSPs remains the same, what will happen to the action potentials on the neuron?

a. probability of triggering action potentials increases

b. probability of triggering action potentials decreases

c. probability of triggering action potentials remains unchanged

d. action potentials would be eliminated

e. action potentials would be conducted with increased velocity

a. probability of triggering action potentials increases

CH 4, Q4: during an excitatory postsynaptic potential in a neural membrane, which of the following is the most important ion flow?

a. sodium ions diffuse out of the cell

b. sodium ions diffuse into the cell

c. potassium ions diffuse out of the cell

d. potassium ions pumped in by the Na+, K+ pump

e. none of the above

b. sodium ions diffuse into the cell

CH 4, Q5: choose the incorrect statement below:

a. conduction velocity of action potentials is slower in myelinated than in unmyelinated axons

b. conduction velocity of action potentials is faster in myelinated than in unmyelinated

c. in saltatory conduction of action potentials, the action potential seems to jump functionally from node to node (nodes of Ranvier)

d. action potentials are of equal magnitude at the beginning and at the end of an axon

a. conduction velocity of action potentials is slower in myelinated than in unmyelinated axons

CH 5, Q1: at the neuromuscular junction, Ca2+ ions are necessary for:

a. binding the transmitter with the postsynaptic receptor

b. facilitating diffusion of the transmitter to the postsynaptic membrane

c. splitting the transmitter in the cleft, thus deactivating the transmitter

d. fusing the presynaptic vesicle with the presynaptic membrane, thus releasing the transmitter

e. metabolizing the transmitter within the presynaptic vesicle

d. fusing the presynaptic vesicle with the presynaptic membrane, thus releasing the transmitter

CH 5, Q2: a drug that would prevent the release of acetylcholine at the neuromuscular junction would cause what, if any, clinical signs?

a. convulsions and excess muscle contractions

b. paralysis

c. no effect on an animal’s movement

b. paralysis

CH 5, Q3: which of the following is true with regard to the termination of synaptic action at the neuromuscular junction?

a. the reuptake of intact acetylcholine molecules into the motor neuron terminal is responsible

b. diffusion of acetylcholine away from the synapse is solely responsible

c. acetylcholinesterase rapidly breaks down acetylcholine into choline & acetate

d. dissociation of acetylcholine from the muscarinic receptor, after binding for several seconds, is solely responsible

c. acetylcholinesterase rapidly breaks down acetylcholine into choline & acetate

CH 5, Q4: several antagonist drugs compete with acetylcholine for the postsynaptic receptor at the neuromuscular junction. if you overdosed your patient with one of these competitive drugs, what would the antidote need to do at the synapse?

a. decrease the release of acetylcholine

b. decrease the effectiveness of acetylcholinesterase

c. decrease the influx of Ca2+ into the motor neuron terminal

d. decrease the action potential frequency on the motor neuron

e. none of the above

b. decrease the effectiveness of acetylcholinesterase

CH 5, Q5: which of the following statements regarding neuron-to-neuron synapses is false?

a. the postsynaptic membrane is always a dendrite

b. dendritic spines increase the surface area of the postsynaptic membrane

c. a single action potential on a presynaptic neuron is usually not sufficient to produce an action potential on a postsynaptic neuron

d. the neurotransmitter is not always released from a morphologically distinct zone of the presynaptic terminal

e. depending on the presynaptic neurotransmitter released and the postsynaptic receptor activated, the postsynaptic membrane can either be depolarized or hyperpolarized

a. the postsynaptic membrane is always a dendrite

CH 6, Q1: troponin and tropomysin are components of which one of the following structures?

a. myosin thick filament

b. sarcolemma

c. T tubule

d. actin thin filament

e. sarcoplasmic reticulum

d. actin thin filament

CH 6, Q2: action potentials in skeletal muscle cells trigger the release from the sarcoplasmic reticulum of what ion critical to the muscle’s contractile process?

a. Ca2+

b. Na+

c. K+

d. Cl-

e. HCO3-

a. Ca2+

CH 6, Q3: gross skeletal muscle belly can be instructed (by the central nervous system) to contract more forcefully by:

a. causing more of its motor units to contract simultaneously

b. increasing the amount of acetylcholine released during each neuromuscular synaptic transmission

c. increasing the frequency of action potentials in the alpha motor neuron’s axon

d. both a and c

e. both b and c

d. both a and c

CH 6, Q4: which of the following is not found in smooth muscle?

a. actin filaments

b. myosin filaments

c. T tubules

d. voltage-gated calcium channels

e. sarcoplasmic reticulum

c. T tubules

CH 6, Q5: choose the incorrect statement below:

a. the muscle fiber and neuronal cell membranes are similar because they both have a resting membrane potential

b. a whole muscle, such as the gastrocnemius muscle, can be made to contract more forcefully by increasing the number of motor units contracting

c. the muscle membrane’s transverse tubular system transmits the action potential to the interior of the muscle cell

d. the muscle cell membrane transmits action potentials by saltatory conduction

e. the shortening of a skeletal muscle during contraction is caused by the sliding together of actin and myosin filaments

d. the muscle cell membrane transmits action potentials by saltatory conduction

CH 6, Q6: which of the following is least likely to be significantly associated with a muscle that is primarily involved in brief, powerful movements?

a. large alpha motor neuron cell body

b. small motor unit

c. fast-twitch fibers

d. white muscle

e. large motor unit

b. small motor unit

CH 7, Q1: which of the following is not always a component of a reflex arc?

a. receptor

b. sensory neurons (CNS afferent)

c. CNS interneuron

d. motor neuron (CNS efferent)

e. target (effector) organ

c. CNS interneuron

CH 7, Q2: which of the following regarding sensory receptors is false?

a. they transduce environmental signals, directly or indirectly, into neuronal action potentials

b. a primary receptor can be a specialized peripheral region of a sensory neuron

c. they directly transduce CNS action potentials into physical activity of a target organ

d. they are the initial component of a reflex arc

c. they directly transduce CNS action potentials into physical activity of a target organ

CH 7, Q3: when the intensity with which a receptor is stimulated is increased, what happens to the frequency of action potentials along the sensory neuron from that receptor?

a. increases

b. decreases

c. no change

a. increases

CH 7, Q4: which of the following is not an example of a segmental reflex?

a. quadriceps stretch reflex

b. pupillary light reflex

c. vestibulospinal postural reflexes

c. vestibulospinal postural reflexes

CH 7, Q5: an intersegmental reflex arc is one in which:

a. the course of the arc is restircted to one or a small number of segments of the CNS

b. no target organ is present

c. no receptor is present

d. the course of the arc traverses several segments of the CNS

e. both b and c

d. the course of the arc traverses several segments of the CNS

CH 8, Q1: if the distance between the origin and insertion tendons is increased (the muscle is stretched), what happens to the frequency of action potentials along the sensory axons leaving the muscle spindles in that muscle?

a. increases

b. decreases

c. does not change

a. increases

CH 8, Q2: activation of the Golgi tendon organ of a given muscle:

a. monosynaptically produces EPSPs on the alpha motor neuron that returns to that muscle

b. is most effectively produced by lengthening of the extrafusal fibers of that muscle

c. polysynaptically produces IPSPs on the alpha motor neuron that returns to that muscle

d. polysynaptically produces EPSPs on the alpha motor neuron that returns to that muscle

e. activates motor neurons that return to the Golgi tendon organ itself

c. polysynaptically produces IPSPs on the alpha motor neuron that returns to that muscle

CH 8, Q3: which of the following is not characteristic of the muscle spindle?

a. encapsulated intrafusal fibers

b. sensitivity to muscle tension

c. sensitivity to dynamic stretching of the muscle

d. lying parallel to the extrafusal muscle fibers

e. sensitivity to steady-state length of the muscle

b. sensitivity to muscle tension

CH 8, Q4: gamma motor neurons:

a. innervate and produce contraction of the equatorial (middle) region of an intrafusal fiber

b. have their cell bodies in the dorsal horn of the spinal cord

c. are never activated at the same time as alpha motor neurons

d. can regulate the sensitivity of the muscle spindle sensory organ

e. innervate and regulate the sensitivity of the Golgi tendon organ

d. can regulate the sensitivity of the muscle spindle sensory organ

CH 10, Q1: a motor neuron pool located most laterally in the ventral horn of the spinal cord is most likely to operate a muscle controlling movement of the:

a. proximal limb

b. neck

c. distal limb

d. abdomen

c. distal limb

CH 10, Q2: which of the following is true regarding decerebrate rigidity?

a. it can result from severe forebrain disease

b. disruption of the cortical control of the medullary reticulospinal neurons is a major contributor to the condition

c. it can result in a fixed, rigid, hobbyhorse-like posture in the quadruped

d. removal of normal inhibition to some antigravity muscles contributes to the condition

e. all of the above are true

e. all of the above are true

CH 10, Q3: which of the following descending brainstem motor pathways control distal limb musculature associated with skilled movement?

a. vestibulospinal tract

b. rubrospinal tract

c. reticulospinal tract

d. tectospinal tract

e. all of the above play a major role in such control

b. rubrospinal tract

CH 10, Q4: the corticospinal (pyramidal) tract, in general, initiates what form of movement?

a. antigravity movement

b. postural adjustment

c. skilled, voluntary, mostly flexor movement

d. tremulous, jerky movement

e.none of the above

c. skilled, voluntary, mostly flexor movement

CH 10, Q5: you are presented with a dog with dense weakness, and proprioceptive placing reaction deficit of his left front and left back legs. a single pathological site could cause these signs if it were located in the:

a. left side of the cervical spinal cord

b. left cerebral cortex

c. right cerebral cortex

d. either a or b

e. either a or c

e. either a or c

CH 10, Q6: the corticospinal tract simultaneously co-activates both the alpha and the gamma lower motor neurons. if the initial co-activation fails to be sufficient to cause the intended shortening of the muscle, sensory neuron activity of the muscle spindle of that muscle will have what influence on the alpha motor neurons to the same muscle?

a. addition of EPSPs

b. addition of IPSPs

c. decrease in action potential frequency

d. no influence

e. either b or d

a. addition of EPSPs

CH 11, Q1: the receptor organ detecting rotary acceleration and deceleration of the head is located in the:

a. utricle

b. saccule

c. ampulla of the semicircular duct

d. scala media of the cochlea

e. vestibular nuclear complex

c. ampulla of the semicircular duct

CH 11, Q2: which two of the following are not generally associated with the macula?

a. otoliths

b. cupula

c. detection of linear acceleration of the head

d. hair cells

e. normal nystagmus

b. cupula

e. normal nystagmus

CH 11, Q3: you are presented with a dog with a head tilt, compulsive circling, and spontaneous nystagmus. the most likely site of this dog’s pathological lesion is the:

a. oculomotor nucleus

b. cerebral cortex

c. vestibular system

d. cervical spinal cord

e. spinal accessory nerve

c. vestibular system

CH 11, Q4: which of the following statements is false?

a. all hair cells of a single utricle are oriented in the same direction with respect to their cilia

b. in a single vestibular hair cell, displacement of the cilia toward the largest cilium increases the firing rate of the hair cell’s associated sensory neuron

c. the axons of sensory neurons synaptically associated with vestibular hair cells form the eighth cranial nerve

d. a gelatinous layer is associated with the vestibular macula

e. the vestibular nuclear complex is located in the brainstem

a. all hair cells of a single utricle are oriented in the same direction with respect to their cilia

CH 11, Q5: if a normal dog is sitting on a piano stool and I start to spin (accelerate) the stool to the right, which of the following will be false regarding the observed nystagmus?

a. the patterns of nystagmus observed at the start of rotation will be seen in reverse briefly after the spinning is abruptly stopped

b. an intact medial longitudinal fasciculus (MLF) is important for producing the nystagmus

c. the nystagmus will continue long after constant velocity is achieved

d. the eye will drift slowly to the left, as far as they can go, and then flip rapidly back to the right

e. nystagmus will often be observed long after the spinning has stopped, while the dog is stationary

c. the nystagmus will continue long after constant velocity is achieved

e. nystagmus will often be observed long after the spinning has stopped, while the dog is stationary

CH 12, Q1: which of the following is principally involved in planning ahead for the next appropriate movement?

a. vestibulocerebellum

b. spinocerebellum

c. cerebrocerebellum

d. archicerebellum

e. both a and b

c. cerebrocerebellum

CH 12, Q2: loss of the cerebellum causes immediately obvious sensory deficits and prevents the initiation of movement

a. true

b. false

b. false

CH 12, Q3: which of the following is true regarding cerebellar Purkinje cells?

a. they are located in the cerebellar cortex

b. they have large cell bodies

c. they have an extensive dendritic tree

d. when active, they inhibit the activity of cells in deep cerebellar nuclei, whose axons leave the cerebellum

e. all the above

e. all the above

CH 12, Q4: loss of the cerebellum causes loss of the muscle stretch reflex.

a. true

b. false

b. false

CH 12, Q5: cats with congenital malformations of the cerebellum often have ataxia, intention tremor, and wide gait.

a. true

b. false

a. true

CH 13, Q1: choose the incorrect statement below:

a. a ganglion is a collection of nerve cell bodies outside the CNS

b. acetylcholine is a chemical transmitter at the parasympathetic postganglionic-to-target organ synapse

c. sympathetic postganglionic neurons are usually longer than those of the parasympathetic system

d. the adrenal medulla secretes mostly norepinephrine and relatively little epinephrine

e. muscarinic acetylcholine receptors are found on peripheral targets of parasympathetic postganglionic neurons

d. the adrenal medulla secretes mostly norepinephrine and relatively little epinephrine

CH 13, Q2: a chemical neurotransmitter between preganglionic and postganglionic neurons of the parasympathetic component of the autonomic nervous system is:

a. norepinephrine

b. acetylcholine

c. epinephrine

d. serotonin

e. γ-aminobutyric acid

b. acetylcholine

CH 13, Q3: a neurotransmitter most often found at the synapse between sympathetic postganglionic neurons and their targets is:

a. norepinephrine

b. epinephrine

c. acetylcholine

d. dopamine

e. γ-aminobutyric acid

a. norepinephrine

CH 13, Q4: which of the following is true regarding sympathetic preganglionic neurons?

a. their cell bodies are located in thoracic and lumbar regions of the spinal cord

b. their axons synapse within the sympathetic ganglion chain

c. their axons for splanchnic nerves

d. their axons travel in the ventral root

e. all the above are true

e. all the above are true

CH 13, Q5: Horner’s syndrome is caused by the loss of:

a. sympathetic innervation to the eye

b. parasympathetic postganglionic innervation to the eye

c. peripheral muscarinic receptors

d. vagus nerve fibers

e. smooth muscle of the iris

a. sympathetic innervation to the eye

CH 14, Q1: a patient whose left pupil is smaller than normal, whose left upper eyelid droops, and whose left “third eyelid’ is abnormally displaced, likely has a lesion of which of the following structures?

a. left oculomotor nerve

b. left vagosympathetic nerve trunk

c. right oculomotor nerve

d. right vagosympathetic nerve trunk

e. left optic nerve

b. left vagosympathetic nerve trunk

CH 14, Q2: which of the following is not characteristic of the cone system?

a. many photoreceptors converging on single bipolar cell

b. good visual acuity

c. multiple photopigments

d. day vision

e. color vision

f. all the above are characteristics of the cone system

a. many photoreceptors converging on single bipolar cell

CH 14, Q3: your friend, a member of the soccer team, is trying without much success to explain the cause for the team’s recent losing trend. a variety of implausible explanations are proposed until she mentions that she is progressively losing vision, but only in her left visual field, and has frequent headaches. you recommend that she see a neurologist because she likely has a lesion in her

a. left optic tract

b. right optic nerve

c. right optic tract

d. optic chiasm

e. left optic radiations

c. right optic tract

CH 14, Q4: which of the following regarding the lens is false?

a. it lies behind the iris

b. it plays an important role in focusing a visual image on the retina

c. ti contains layered lens fibers

d. it shape does not normally change

e. an increase in its opacity is called a cataract

d. it shape does not normally change

CH 14, Q5: you examine a patient’s pupillary light reflexes. shining a light into the left eye produces both a positive direct and a positive consensual pupillary response. however, shining the light into the right eye produces neither a direct nor an indirect pupillary response. this patient’s pathological lesion is located in which of the following structures?

a. left optic nerve

b. left oculomotor nerve

c. right optic nerve

d. right oculomotor nerve

e. left primary visual cortex

c. right optic nerve

CH 15, Q1: obstruction of CSF flow at the cerebral aqueduct would lead to dilation (enlargement) of the:

a. lateral ventricles

b. fourth ventricle

c. central canal of the spinal cord

d. subarachnoid space

e. conus medullaris

a. lateral ventricles

CH 15, Q2: CSF is principally formed at the:

a. arachnoid villi

b.cerebral aqueduct

c. choroid plexuses

d. subarachnoid space

e. dorsal sagittal sinus

c. choroid plexuses

CH 15, Q3: you are performing a spinal tap on an aesthetized horse and measuring CSF pressure. cellular debris has obstructed the arachnoid villi following meningitis. what would you expect regarding CSF pressure

a. pressure would be higher than normal

b. pressure would be lower than normal

c. pressure would be normal

a. pressure would be higher than normal

CH 15, Q4: for many veterinary species, diagnostic sampling of CSF is often performed by placing a sampling needle in the:

a. lateral ventricles

b. dorsal sagittal sinus

c. third ventricle

d. cerebral aqueduct

e. cisterna magna

e. cisterna magna

CH 15, Q5: which two of the following are false regarding the blood-brain barrier (BBB)?

a. the BBB is very effective at the circumventricular organs of the brain

b. astrocytic end-feet are thought to be partially responsible for the development of the BBB

c. brain capillaries generally have a high number of endothelial tight junctions

d. many dyes injected into the blood can typically penetrate most tissues of the body, but usually not the brain

e. small, uncharged, lipid-soluble molecules do not generally pass through the BBB

a. the BBB is very effective at the circumventricular organs of the brain

e. small, uncharged, lipid-soluble molecules do not generally pass through the BBB

CH 16, Q1: which of the following regarding EEG is false?

a. its measurement relies on volume conduction

b.its predominantly measures postsynaptic potentials in the cerebral cortex

c. it is commonly used to measure the activity of a small number of neurons

d. it is a measure of the spontaneous activity of brain tissue

e. both a and d

c. it is commonly used to measure the activity of a small number of neurons

CH 16, Q2: a lesion in which of the following brain structures would be least likely to have a significant effect on the EEG?

a. cerebral cortex

b. thalamus

c. hypothalamus

d. cerebellum

e. reticular activating system

d. cerebellum

CH 16, Q3: which of the following statements is true?

a. a slow-frequency, high-amplitude EEG is said to be “desynchronized.”

b. the EEG alone is used to confirm brain death

c. there are some periods of high-frequency, low-amplitude EEG during sleep

d. the EEG is usually measured in response to the stimulation of a sensory receptor organ

c. there are some periods of high-frequency, low-amplitude EEG during sleep

CH 16, Q4: the BAER requires averaging out the random background EEG activity before it can be observed.

a. true

b. false

a. true

CH 16, Q5: a brain tumor may cause focal slowing of the EEG from the brain tissue immediately surrounding the tumor.

c

b. false

a. true

CH 17, Q1: which of the following is the first to be displaced by sound energy entering the ear?

a. oval window

b. tectorial membrane

c. basilar membrane

d. tympanic membrane

e. stapes

d. tympanic membrane

CH 17, Q2: hair cells similar to those of the organ of Corti are important for the function of which two of the following sensory organs?

a. muscle spindle

b. retina

c. crista ampullaris

d. golgi tendon organ

e. utricular maccula

c. crista ampullaris

e. utricular maccula

CH 17, Q3: which one of the following statements is false?

a. an increase in sound wave frequency is perceived as an increase in pitch

b. the area of greatest displacement of the basilar membrane moves closer to its base (toward the oval window) as the sound wave frequency decreases

c. a decrease in sound wave amplitude is perceived as decreased loudness

d. an increase in sound wave amplitude displaces a longer region of the basilar membrane

e. contraction of muscles attached to the ossicles reduces the sound energy reaching the inner ear

b. the area of greatest displacement of the basilar membrane moves closer to its base (toward the oval window) as the sound wave frequency decreases

CH 17, Q4: which one of the following cranial nerves transmits sound to the brain?

a. 2

b. 7

c. 8

d. 10

c. 8

CH 17, Q5: of the following brain nuclei, which one receives auditory information last?

a. medial geniculate nucleus

b. cochlear nuclei

c. superior olivary complex

d. inferior colliculus

a. medial geniculate nucleus