Lecture Exam #3
E
IPSPs (inhibitory postsynaptic potentials) A) are local depolarizations. B) block the efflux of potassium ions. C) increase membrane permeability to sodium ions. D) block the efflux of calcium ions. E) are local hyperpolarizations.
D
Identfy the structure labeled "1." A) somatic motor neuron B) astrocyte C) ganglionic neuron D) preganglionic neuron E) sensory neuron
E
Identify the round structure labeled "3." A) spinal nerve B) rami communicantes C) dorsal root ganglion D) intramural ganglion E) chain ganglion
D
Identify the structure labeled "5." A) collateral branch B) dendritic spines C) axons D) synaptic terminals E) telodendria
E
If the dorsal root of a spinal nerve is severed, A) output to skeletal muscles would be blocked. B) the brain would not be able to communicate with that level of the spinal cord. C) the spinal cord would not be able to process information at that level. D) output to visceral organs would be blocked. E) sensory input would be blocked.
E
In meningitis, A) CSF flow can be disrupted. B) inflammation of the meninges occurs. C) viruses can be the cause. D) bacteria can be the cause. E) All of the answers are correct.
A
In the condition ______, a virus infects dorsal root ganglia, causing a painful rash whose distribution corresponds to that of the affected sensory nerves as seen in their dermatomes. A) shingles B) chickenpox C) Hodgkin's disease D) myasthenia gravis E) neuronal damage
B
In which plexus does the ulnar nerve arise? A) sacral B) brachial C) lumbar D) cervical E) cranial
E
Many medications introduced into the bloodstream cannot directly affect the neurons of the CNS because A) astrocytes form a capsule around neurons. B) ependymal cells restrict the flow of interstitial fluid between capillaries and the neurons. C) the neurolemma is impermeable to most molecules. D) oligodendrocytes form a continuous myelin sheath around the axons. E) the endothelium of CNS capillaries forms a blood-brain barrier.
C
Muscles of the neck and shoulder are innervated by spinal nerves from the ______ region. A) coccygeal B) thoracic C) cervical D) sacral E) lumbar
A
Neurons in which dendritic and axonal processes are continuous and the soma lies off to one side are called A) unipolar. B) anaxonic. C) bipolar. D) tripolar. E) multipolar.
C
Opening of sodium channels in the axon membrane causes A) repolarization. B) inhibition. C) depolarization. D) hyperpolarization. E) increased negative charge inside the membrane.
B
Preganglionic fibers leave the CNS and then synapse on A) afferent neurons. B) ganglionic neurons. C) visceral reflex responses. D) postganglionic fibers. E) motor neurons.
D
Splanchnic nerves A) are formed of parasympathetic fibers. B) connect chain ganglia. C) originate from first-order neurons located in the upper five thoracic segments of the spinal cord. D) innervate the viscera or internal organs. E) control sympathetic function of structures in the thorax.
C
Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated A) impulse transmission. B) temporal summation. C) spatial summation. D) hyperpolarization. E) inhibition of the impulse.
C
The ______ division of the autonomic nervous system is said to function during "rest and digest." A) visceral B) sympathetic C) parasympathetic D) somatomotor E) thoracolumbar
A
The ______ nerve, which arises from the cervical plexus, innervates the diaphragm. A) phrenic B) radial C) ansa cervicalis D) lesser occipital E) sciatic
C
The ______ nervous system is composed of the brain and spinal cord. A) efferent B) afferent C) central D) autonomic E) peripheral
C
The ______ reflex complements the flexor reflex by activating contralateral muscles. A) tendon B) stretch C) crossed extensor D) flexor E) reciprocal
E
The adrenal medullae secrete A) epinepherine. B) renin. C) norepinepherine. D) medullin. E) both epinepherine and norepinepherine.
E
The axon is connected to the soma at the A) telodendria. B) synaptic terminal. C) synapse. D) collaterals. E) axon hillock.
B
The brachial plexus gives rise to all of the following nerves except the A) ulnar. B) phrenic. C) musculocutaneous. D) radial. E) median.
E
The celiac ganglia innervate which of the following? A) pancreas B) liver C) spleen D) stomach E) All of the answers are correct.
C
The complex, interwoven network formed by contributions from the ventral rami of neighboring spinal nerves is termed a(n) A) dermatome. B) autonomic nerve. C) plexus. D) tract. E) lateral nerve.
B
The cranial nerves that innervate the eye muscles are A) I, II, and III. B) III, IV, and VI. C) III and V. D) II, III, and IV. E) II and VI.
E
The cytoplasm that surrounds the nucleus of a neuron is called the A) nucleoplasm. B) sarcoplasm. C) protoplasm. D) neuroplasm. E) perikaryon.
B
The dorsal root ganglia mainly contain A) axons of sensory neurons. B) cell bodies of sensory neurons. C) axons of motor neurons. D) synapses. E) cell bodies of motor neurons.
C
The flexor reflex A) prevents a muscle from overstretching. B) prevents a muscle from generating damaging tension. C) moves a limb away from a painful stimulus. D) usually depends on cranial neurons. E) is an example of a monosynaptic reflex.
C
The following are the main steps in the generation of an action potential. 1. Sodium channels are inactivated. 2. Voltage-gated potassium channels open and potassium moves out of the cell, initiating repolarization. 3. Sodium channels regain their normal properties. 4. A graded depolarization brings an area of an excitable membrane to threshold. 5. A temporary hyperpolarization occurs. 6. Sodium channel activation occurs. 7. Sodium ions enter the cell and depolarization occurs. What is the proper sequence of these events? A) 4, 6, 7, 3, 2, 5, 1 B) 2, 4, 6, 7, 1, 3, 5 C) 4, 6, 7, 1, 2, 3, 5 D) 4, 2, 5, 6, 7, 3, 1 E) 6, 7, 4, 1, 2, 3, 5
B
The ion that triggers the release of acetylcholine into the synaptic cleft is A) sodium. B) calcium. C) potassium. D) chloride. E) magnesium.
D
The layer of connective tissue that surrounds a fascicle within a peripheral nerve is the A) endosteum. B) epimysium. C) epineurium. D) perineurium. E) endoneurium.
B
The layer of connective tissue that surrounds individual axons within a peripheral nerve is termed the A) aponeurium. B) endoneurium. C) metaneurium. D) perineurium. E) subneurium.
B
The layer of meninges in direct contact with the spinal cord is the A) arachnoid. B) pia mater. C) subarachnoid space. D) dura mater. E) choroid plexus.
C
The loss of feeling and movement of the legs is termed A) spinal shock. B) spinal transection. C) paraplegia. D) hemiplegia. E) quadriplegia.
D
The myelin sheath that covers many CNS axons is formed by A) microglia. B) satellite cells. C) ependymal cells. D) oligodendrocytes. E) astrocytes.
C
The outermost connective-tissue covering of nerves is the A) perineurium. B) endoneurium. C) epineurium. D) epimysium. E) endomysium.
E
The part of the peripheral nervous system that carries sensory information to the CNS is designated A) motor. B) somatic. C) autonomic. D) efferent. E) afferent.
D
The period during which an excitable membrane can respond again, but only if the stimulus is greater than the threshold stimulus, is the ______ period. A) resting B) lag C) absolute refractory D) relative refractory E) stationary
E
The peroiod during which an excitable membrane cannot respond to further stimulation is the ______ period. A) stationary B) relative refractory C) lag D) resting E) absolute refractory
B
The preganglionic fibers that connect a spinal nerve with an autonomic ganglion in the thoracic and lumbar region of the spinal cord and carries visceral motor fibers that are myelinated form the A) dermatomes. B) white rami communicantes. C) ventral ramus. D) gray rami communicantes. E) dorsal ramus.
A
The primary motor cortex is the surface of the A) precentral gyrus. B) corpus callosum. C) arcuate gyrus. D) insula. E) postcentral gyrus.
E
The rabies virus travels to the CNS via A) subcutaneous connective tissue. B) anterograde axoplasmic transport. C) cerebrospinal fluid. D) blood vessels. E) retrograde axoplasmic transport.
C
The reflex that prevents a muscle from exerting too much tension is the ______ reflex. A) stretch B) reciprocal C) tendon D) crossed extensor E) flexor
B
The sense of taste projects to the gustatory cortex located in the ______ and ______. A) corpus callosum and fornix B) insula C) precentral gyrus and prefrontal cortex D) parietal lobe E) temporal lobe
B
The sensory loss and muscle weakness associated with multiple sclerosis are a consequence of A) excessive myelin layers around the axonal fibers. B) demyelination. C) a neuron without a nuerilemma. D) too few nodes of Ranvier. E) a neuron not having a myelin sheath.
E
There are ____ pairs of cranial nerves. A) 6 B) 2 C) 31 D) 22 E) 12
C
Which area of the graph shows when potassium channels open? A) 1 B) 2 C) 3 D) 4
A
Which of the cranial nerves is named for the fact that it "wanders," that is, innervates structures throughout the thorax and abdomen? A) X B) XI C) VIII D) XII E) IX
E
Which of the following is a function of the thalamus? A) secrete cerebrospinal fluid B) secrete melatonin C) regulate food intake D) store memories E) process sensory information and relay it to the cerebrum
D
______ monitor the position of skeletal muscles and joints. A) Exteroceptors B) Internoceptors C) Photoreceptors D) Proprioceptors E) Pressoreceptors
B
______ open or close in response to binding specific molecules. A) Voltage-gated channels B) Chemically gated channels C) Activated channels D) Leak channels E) Voltage-gated and chemically gated channels
B
A viral disease that destroys the cells of the anterior gray horn will A) affect visceral motor function. B) lead to skeletal muscle weakness or paralysis. C) block autonomic regulation. D) mainly interfere with crude touch and temperature sense. E) interfere with position sense.
E
Adrenergic synapses release the neurotransmitter A) GABA. B) acetylcholine. C) serotonin. D) dopamine. E) norepinepherine.
C
An inhaler used to treat airway constriction in asthma or allergy might contain a drug that A) activates β2 adrenergic receptors or activates muscarinic cholinergic receptors. B) blocks β2 adrenergic receptors. C) activates β2 adrenergic receptors. D) activates β1 adrenergic receptors. E) activates muscarinic cholinergic receptors.
C
At the normal resting potential of a typical neuron, its sodium-potassium exchange pump transports A) 2 intracellular sodium ions for 1 extracellular potassium ion. B)1 intracellular sodium ion for 2 extracellular potassium ions. C) 3 intracellular sodium ions for 2 extracellular potassium ions. D) 3 intracellular sodium ions for 1 extracellular potassium ion. E) 3 extracellular sodium ions for 2 intracellular potassium ions.
E
Autonomic disorders would not cause A) excessive perspiration. B) problems in maintenance of blood pressure. C) sexual arousal. D) appetite. E) problems related to skeletal muscle function.
E
Bill contracts a viral disease that destroys cells in the posterior gray horns in his spinal cord. As a result, which of the following would you expect? A) uncontrollable sweating of his feet B) problems moving his legs C) inability to breathe D) problems with moving his arms E) loss of sensation in his torso
D
Cerebrospinal fluid flows within the A) filum terminale. B) arachnoid mater. C) dura mater. D) subarachnoid space. E) pia mater.
E
Changes in the central nervous system that accompany aging include A) decrease in the number of neurons. B) reduction in brain size and weight. C) changes in synaptic organization in the brain. D) decreased blood flow to the brain. E) All of the answers are correct.
C
Cholinergic synapses release the neurotransmitter A) serotonin. B) GABA. C) acetylcholine. D) adrenalin. E) norepinepherine.
D
Deteriorating changes in the distal segment of an axon as a result of a break between it and the soma is called ______ degeneration. A) central B) peripheral C) neural D) Wallerian E) conduction
E
Difficulty in swallowing may be a sign of damage to which cranial nerve(s)? A) vagus B) hypoglossal C) hypoglossal D) facial E) glossopharyngeal
B
Drugs known as beta-blockers may be useful for treating A) diarrhea. B) excessive heart rate. C) prostate disorders. D) constipation. E) excessive salivation.
E
During sympathetic activation, ______ occurs. A) sweating B) elevated blood glucose C) elevated blood pressure D) elevated heart rate E) All of the answers are correct.
C
In an adult, the conus medullaris is found at about A) L5. B) C1. C) L1. D) T6. E) T10.
A
Neurons that have several dendrites and a single axon are called A) multipolar. B) bipolar. C) anaxonic. D) unipolar. E) tripolar.
B
The site of intercellular communication between a neuron and another cell is the A) telodendria. B) synapse. C) synaptic terminals. D) hillock. E) collateral.
E
The spinal cord is part of the ______ nervous system. A) autonomic B) somatic C) peripheral D) afferent E) central
C
The structures labeled "1" are dendrites. Their membranes contain numerous chemically-gated ion channels. A) The first statement is true but the second statement is false. B) Both statements are false. C) Both statements are true. D) The first statement is false but the second statement is true.
C
The sympathetic division of the ANS is also known as which of the following? A) somatic division B) craniosacral division C) thoracolumbar division D) resting division E) lumbosacral division
C
The tough, fibrous, outermost covering of the spinal cord is the A) pia mater. B) periosteum. C) dura mater. D) arachnoid. E) epidural block.
A
The ventral root of a spinal nerve contains A) axons of motor neurons. B) axons of sensory neurons. C) interneurons D) cell bodies of motor neurons. E) cell bodies of sensory neurons.
E
The visual cortex is located in the A) temporal lobe. B) parietal lobe. C) insula. D) frontal lobe. E) occipital lobe.
B
During the procedure known as a(an) ______, a needle is inserted into the subarachnoid space in the inferior lumbar region. A) EEG B) lumbar puncture C) laminectomy D) thoracic tap E) encephalomyelogram
A
Functions of astrocytes include all of the following except A) conducting action potentials. B) forming a three-dimentional framework for the CNS. C) maintaining the blood-brain barrier. D) guiding neuron development. E) responding to neural tissue damage.
E
Ion channels that are always open are called ______ channels. A) gated B) active C) local D) regulated E) leak
E
Neurotransmitters ready for release are stored in synaptic A) mitochondria. B) terminals. C) neurosomes. D) telodendria. E) vesicles.
A
The ______ nervous system contols the skeletal muscles. A) somatic B) parasympathetic C) sympathetic D) autonomic E) afferent
B
What is contained inside the structure labeled "5"? A) sodium ions B) neurotransmitter molecules C) calcium ions D) acetylcholinesterase E) neuroglia
E
What is occuring at the area labeled #4? A) Excessive depolarization of the axon has occurred. B) Chemically gated potassium channels have opened. C) An inhibitory stimulus has occurred. D) Sodium ions have been pumped out of the neuron. E) Excessive potassium has diffused out causing hyperpolarization.
E
What is occurring in the area between #2 and #3? A) Repolarization of the axon due to sodium ions leaving the axon is occurring. B) Potassium ions are entering the axon and causing depolarization. C) Chemically gated sodium channels are open and sodium is diffusing into the axon. D) An excitatory graded potential is occurring. E) Sodium ions are entering the axon and causing depolarization.
C
When a second EPSP (excitatory postsynaptic potential) arrives at a single synapse before the effects of the first have disappeared, what occurs? A) hyperpolarization B) inhibition of the impulse C) temporal summation D) decrease in speed of impulse transmission E) spatial summation
E
Hydrocephalus, or "water on the brain," may result from A) excessive water intake. B) blockage of circulation of CSF. C) excessive production of cerebrospinal fluid. D) deficient production of cerebrospinal fluid. E) blockage of CSF circulation or excessive CSF production.
A
Puffer fish poison blocks voltage-gated sodium channels like a cork. What effect would this neurotoxin have on the function of neurons? A) The axon would be unable to generate action potentials. B) The absolute refractory period would be shorter than normal. C) Neurons would depolarize more rapidly. D) Action potentials would lack a repolarization phase. E) None, because the chemically gated sodium channels would still function.
B
Reflexes based on synapses formed during development are ______ reflexes. A) acquired B) innate C) somatic D) vegetative E) visceral
C
Sensory innervation of the lower teeth and gums is by the ______ nerve. A) ophthalmic branch of the trigeminal B) hypoglossal C) mandibular branch of the trigeminal D) glossopharyngeal E) maxillary branch of the trigeminal
A
Small, wandering cells that engulf debris and pathogens in the CNS are called A) microglia. B) ependymal cells. C) astrocytes. D) oligodendrocytes. E) satellite cells.
A
Spinal nerves are A) both sensory and motor. B) interneuronal. C) purely motor. D) purely sensory. E) involuntary.
E
Sympathetic preganglionic neurons are ______ and have ______ axons. A) short; unmyelinated B) long; myelinated C) long; unmyelinated D) intermediate; small E) short; myelinated
E
The neurilemma of axons in the peripheral nervous system is formed by A) astrocytes. B) satellite cells. C) microglia. D) oligodendrocytes. E) Schwann cells.
C
Which of the following is not a function of the neuroglia? A) support B) secretion of cerebrospinal fluid C) memory D) phagocytosis E) maintenance of blood-brain barrier
C
Which of the following is not a recognized structural classification for neurons? A) anaxonic B) unipolar C) pseudopolar D) multipolar E) bipolar
E
Which of the following lies between the cerebrum and the brain stem? A) pons B) medulla oblongata C) mesencephalon D) cerebellum E) diencephalon
C
______ is a disorder affecting the ability to speak or read. A) Ataxia B) Bell's palsy C) Aphasia D) Apraxia E) Dysphagia
A
______ line the brain ventricles and spinal canal. A) Ependymal cells B) Satellite cells C) Oligodendrocytes D) Microglia E) Astrocytes
