A & P Lecture Exam #4 (Questions)
A neuron at rest has a charge difference across its cell membrane, with the interior of the cell negative relative to the exterior. This difference in charge across the plasma membrane is referred to as ________ potential. *refractory *depolarization *action *graded *resting
resting
The central nervous system is enclosed by membranes or meninges called the *dura mater, alma mater, and pia mater *glial, Schwann, and interstitial *dura mater, pia mater, and arachnoid *pleura, parietal, and arachnoid *fore, mid, and hind meninges
Dura mater, pia mater, and arachnoid
Which one of the following types of neurotransmitter functions as an inhibitory agent, typically suppressing the sensation of pain? *endorphins *epinephrine *acetylcholine *serotonin
Endorphins
Neurotransmitters always cause depolarization of the postsynaptic membrane TRUE FALSE
FALSE
An action potential is a long or rapid release of energy, generated by the sodium-potassium pumps of neurons. TRUE FALSE
False
The strength and duration of a stimulus determine the amplitude of an action potential. TRUE FALSE
False
All of the following are associated with storage of long-term memory, EXCEPT __________. *limbic system *the formation of new synapses *permanent changes in neurons *the cerebral cortex
Limbic system
Which of the following parts of the brain is associated with emotions and behavior? *limbic system *corpus callosum *cerebellum *hypothalamus *medulla oblongata
Limbic system
Short-term memory is associated with the ________, whereas long-term memory is associated with the ________. *cerebral cortex, limbic system *limbic system, cerebral cortex *hypothalamus, cerebral cortex *limbic system, hypothalamus *cerebral cortex, hypothalamus
Limbic system, cerebral cortex
Control of respiratory rate, heart rate, and blood pressure is integrated through the *medulla oblongata *cerebral cortex *cerebellum *hypothalamus *thalamus
Medulla oblongata
Which one of the following cells transmit impulses away from the central nervous system to the muscles and other organs? *sensory neurons *motor neurons *neuroglia *interneurons *dendrites
Motor neurons
White matter of the spinal cord contains __________, while gray matter contains __________. *nerve tracts; cell bodies *unmyelinated axons; myelinated axons *motor neurons; sensory neurons *cell bodies; nerves
Nerve tracts; cell bodies
Which of the following cell types makes up the majority of cells in the nervous system? *interneurons *neuroglial cells *motor neurons *sensory neurons
Neuroglial cells
Graded potentials __________. *always depolarize the membrane *grow stronger as they spread through the cell body *are permanent changes in the resting potential of a membrane *occur in a local area of the membrane
Occur in a local area of the membrane
Which one of the following divisions of the nervous system predominates during the relaxed state? *sensory division *parasympathetic division *endocrine division *sympathetic division *somatic division
Parasympathetic divsion
By which one of the following methods is a stronger stimulus coded by neurons differently from a weaker stimulus? *A stronger stimulus results in more action potentials/unit time. *A stronger stimulus results in greater depolarization. *A stronger stimulus results in action potentials, which travel faster. *A stronger stimulus results in prolonged influx of Na+ ions and a delay before repolarization. *A stronger stimulus results in hyperpolarization of the neuron.
A stronger stimulus results in more action potentials/unit time
Amyotrophic lateral sclerosis (ALS) is a demyelinating disease that results from nerve damage in the *brain *diaphragm *sensory nerves *spinal cord
Spinal cord
Excitatory neurotransmitters encourage the generation of new electrical impulses by which one of the following? *inhibiting postsynaptic neurons from repolarizing *stimulating depolarization of postsynaptic neurons *inhibiting presynaptic neurons from depolarizing *stimulating depolarization of presynaptic neurons *stimulating saltatory conduction
Stimulating depolarization of postsynaptic neurons
From an evolutionary standpoint, which of the following structures is considered the oldest, most primitive division of the brain? *midbrain *cerebrum *medulla oblongata *forebrain *hindbrain
hindbrain
Which of the following statements correctly characterizes an action potential? *A stronger action potential will travel faster than a weaker action potential. *Action potentials are more likely to result when the membrane is hyperpolarized. *Action potentials reverse the membrane potential so that the interior is negatively charged and the exterior is positively charged. *Action potentials are initiated by depolarization of the membrane to threshold.
Action potentials are initiated by depolarization of the membrane to threshold
During a brain surgery, a surgeon passes an instrument through the dura mater. Which one of the following does the surgeon pass through next? *vertebrae *bones of the skull *pia mater *arachnoid *cerebrospinal fluid
Arachnoid
Oligodendrocytes are similar to Schwann cells in that they *help neurons regenerate after injury *conduct nerve impulses *are a type of neuroglial cell *are located in the central nervous system *are located in the peripheral nervous system
Are a type of neuroglial cells
Which of the following statements regarding infections of the nervous system is accurate? *The blood-brain barrier is not effective at preventing microorganisms from entering the central nervous system. *Bacterial meningitis is generally more severe than viral meningitis. *Most cases of encephalitis are caused by bacteria. *Rabies can be treated with antibiotics.
Bacterial meningitis is generally more severe than viral meningitis
In the primary somatosensory area, __________. *body parts that are coordinated with motor responses are represented by a greater area than body parts that are not *body parts that are extremely sensitive are represented by a greater area than less sensitive body parts *the brain processes visual input *conscious thought is coordinated with motor responses
Body parts that are extremely sensitive are represented by a greater area than less sensitive body parts
Which of the following influence(s) the speed of an action potential? *the presence of a myelin sheath *the diameter of the axon *the extent of depolarization that initiates the action potential *both the presence of a myelin sheath and the diameter of the axon
Both the presence of myelin sheath and the diameter of the axon
Which one of the following is NOT directly involved in the production of a typical spinal reflex? *brain *sensory neuron *motor neuron *stimulus *interneuron
Brain
Axons branch into axon terminals, which have ________ located at the terminal ends. *dendrites *Schwann cells *nodes of Ranvier *hillocks *bulbs
Bulbs
During synaptic transmission, the influx of ________ causes vesicles in the axon bulb to fuse with the cell membrane, releasing ________. *mitochondrion, neurons *vesicles, neurons *Ca+2, neurotransmitter *neurons, mitochondrion *neurotransmitters, Ca+2
Ca+2, neurotransmitter
Which one of the following events associated with the transmission of an impulse across a synapse occurs last? *Action potential arrives at an axon terminal. *Calcium diffuses into an axon terminal. *Neurotransmitter is released into synaptic cleft. *Neurotransmitter binds to receptors on postsynaptic membrane. *Chemically gated channels for sodium open.
Chemically gated channels for sodium open
The three main anatomical and functional divisions of the brain are the *frontal, parietal, occipital *cerebellum, medulla oblongata, pons *ventricles, meninges, nerve tracts *hypothalamus, thalamus, pituitary *forebrain, midbrain, hindbrain
Forebrain, midbrain, hindbrain
Convergence occurs when several presynaptic cells *form a synapse with a single postsynaptic cell *depolarize simultaneously *activate the sodium-potassium pump of a Schwann cell *depolarize sequentially *form a synapse with multiple postsynaptic cells
Form a synapse with a sing postsynaptic cell
Regulation of the production of breast milk, carbohydrate metabolism, and temperature control are some of the functions of the *thalamus *medulla oblongata *midbrain *hypothalamus *frontal lobe
Hypothalamus
Which of the following would occur in a neuron if calcium could NOT enter the axon terminal? *absence of graded potentials *inability to release neurotransmitters *inability to manufacture neurotransmitters *absence of action potentials
Inability to release neurotransmitters
Which one of the following activities would be facilitated by the sympathetic nervous system? *increased blood pressure *increased bladder contraction *increased digestion and absorption *decreased heart rate *decreased respiratory rate
Increase blood pressure
An __________ neurotransmitter causes __________ of the postsynaptic membrane. *inhibitory; hyperpolarization *inhibitory; depolarization *excitatory; hyperpolarization
Inhibitory; hyperpolarization
Electrical impulses are transmitted between components of the central nervous system via which one of the following? *macrophages *glial cells *motor neurons *interneurons *sensory neurons
Interneurons
An action potential __________. *is both all-or-none and self-propagating *is all-or-none *is self-propagating *occurs at a speed that is dependent on the speed at which a threshold level is reached
Is both all-or-non and slef-propagating
All of the following statements about psychoactive drugs are TRUE EXCEPT which one? *Many psychoactive drugs lead to dependence, tolerance, and addiction. *Psychoactive drugs change the normal patterns of brain electrical activity. *Psychoactive drugs are able to cross the blood-brain barrier. *Psychoactive drugs typically bind to the medulla oblongata. *Psychoactive drugs directly affect neurotransmitters.
Psychoactive drugs typically bind to the medulla oblongata
During which one of the following phases of an action potential do the sodium channels close and potassium channels open, releasing potassium from the neuron? *reestablishment of resting potential *depolarization *repolarization *saltatory propagation *both depolarization and repolarization
Repolarization
A neuron at rest has a charge difference across its cell membrane, with the interior of the cell negative relative to the exterior. This difference in charge across the plasma membrane is referred to as ________ potential. *refractory *depolarization *action *graded *resting
Resting
The motor division of the peripheral nervous system sends information to all of the following EXCEPT which one? *parasympathetic division *autonomic division *somatic division *sympathetic division *sensory division
Sensory division
Which one of the following establishes and maintains the resting potential? *sodium-potassium pump *K+ leak channel *depolarization *repolarization *Na+ leak channel
Sodium-potassium pump
Both voluntary and involuntary skeletal muscle movement are controlled through which one of the following divisions of the nervous system? *parasympathetic division *sensory division *sympathetic division *somatic division *endocrine division
Somatic division
All of the following are functions of the myelin sheath EXCEPT which one? *The myelin sheath plays an important role in synaptic transmission. *The myelin sheath is involved in the repair of damaged neurons in the peripheral nervous system. *The myelin sheath speeds up transmission of action potentials. *The myelin sheath insulates a neuron and saves the neuron energy.
The myelin sheath plays an important role in synaptic transmission
Which one of the following steps occurs during the absolute refractory period? *The neuron cannot generate an action potential. *Sodium and potassium channels open. *Sodium channels open, releasing sodium ions into the neuron; potassium channels close. *Potassium channels open, releasing potassium ions from the neuron; sodium channels close. *A nerve impulse is propagated.
The neuron cannot generate an action potential
Saltatory conduction is *the process of conduction leaping along myelinated neurons *the movement of an electrical impulse from the dendrite to an axon *the activation of the fight-or-flight response *the movement of neurotransmitters across a synaptic cleft *an action potential generated in taste receptors or buds
The process of conduction leaping along myelinated neurons
Which of the following characteristics of the neuron cell membrane contributes to the maintenance of the resting membrane potential? *The sodium-potassium pump transports three sodium ions out of the cell for every two potassium ions it pumps into the cell. *The cell body is wrapped in a myelin sheath that prevents the movement of ions across the membrane. *The membrane is very permeable to calcium, creating a steady flow of calcium into the cell. *The membrane is very permeable to sodium, creating a steady flow of sodium into the cell.
The sodium-potassium pump transports three sodium ions out of the cell for every two potassium ions in pumps into the cell
Which of the following is characteristic of psychoactive drugs? *They alter the speed with which action potentials travel. *They can alter the amplitude of action potentials. *They do not readily cross the blood-brain barrier. *They alter levels of neurotransmitters.
They alter levels of neurotransmitters
What do multiple sclerosis and ALS (amyotropic lateral sclerosis) have in common? *They both are more common in young men than in young women. *They both damage the myelin sheath, slowing action potential transmission. *They both impair the initiation of action potentials. *They both impair nerve function in the peripheral nervous system.
They both damage the myelin sheath, slowing action potentials transmission
All of the following are directly involved in synaptic transmission, EXCEPT __________. *chemical-sensitive ion channels on the postsynaptic membrane *voltage-sensitive ion channels on the postsynaptic membrane *neurotransmitters *Ca+2
Voltage-sensitive ion channels on the postsynaptic membrane
The reticular formation is associated with *water and solute balance *conscious thought *wakefulness, posture, and muscle tone *regulation of heart rate and blood pressure *vision
Wakefulness, posture, and muscle tone
Long-term memory occurs __________. *in the cerebellum *when neurons are permanently changed *in the limbic system *when exceptionally strong action potentials occur
When neurons are permanently changed
