NDSU Human Anat I- Exam 2
Compared to the electrical gradient for sodium at rest, the electrical gradient for potassium at rest is __________. - in the same direction and of the same magnitude. - in the same direction but of greater magnitude. - in the opposite direction but of the same magnitude. - in the same direction but of lesser magnitude.
- in the same direction and of the same magnitude.
Around what transmembrane potential does threshold commonly occur? +60 mV -60 V -70 mV -60 mV
-60 mV
In a typical neuron, what is the equilibrium potential for potassium? 0 mV -70 mV -90 mV +66 mV
-90 mV
Approximately how fast do action potentials propagate in unmyelinated axons in humans? 120 meters per second 0.1 meters per second 1 meter per second 12 meters per second
1 meter per second
Sensory information entering the posterior ramus of the spinal nerve is most likely coming from which part of the body? Exteroreceptors on back Interoreceptors of limbs Interoreceptors of the visceral organs Exteroreceptors on limbs Exteroreceptors on body wall
Exteroreceptors on back
A person has an accident that damages only the entire right half of the cervical spinal cord. Which of the following sets of symptoms are possible? Fine touch is lost in the left leg. Fine touch is lost in the right leg. Pain is lost in the left leg. Pain is lost in the right leg. Pressure is lost in the left leg. Pressure is lost in the right leg.
Fine touch is lost in the right leg. Pain is lost in the left leg. Pressure is lost in the left leg.
Which statement best describes the location and organization of parasympathetic ganglia and ganglionic neurons? Ganglia are located in or near to their target organ, and both the pre- and postganglionic neurons use acetylcholine as their neurotransmitter. Ganglia are located in the target organs. Both the pre- and postganglionic neurons use epinephrine as their neurotransmitter. Ganglia are located near the spinal cord. Both the pre- and postganglionic neurons use norepinephrine as their neurotransmitter. Ganglia are located near the spinal cord. The preganglionic neurons use acetylcholine as their neurotransmitter, while most of the postganglionic neurons use norepinephrine as a neurotransmitter.
Ganglia are located in or near to their target organ, and both the pre- and postganglionic neurons use acetylcholine as their neurotransmitter.
Which of these statements about the afferent division of the nervous system is true? It ascends with motor information. It descends with sensory information. It ascends with sensory information. It descends with motor information.
It ascends with sensory information.
Which nerve plexus innervates the muscles of the neck and diaphragm? thoracic brachial cervical lumbar
cervical
The cerebrospinal fluid (CSF) leaves the central nervous system (CNS) and enters the circulation at the __________. arachnoid trabeculae lateral apertures pia mater arachnoid granulations
arachnoid granulations
Leak channels allow the movement of potassium and sodium ions by what type of membrane transport? - simple diffusion - active transport - channel-mediated diffusion - facilitated diffusion
channel-mediated diffusion
The electrochemical gradient for sodium ions in a neuron when the transmembrane potential is at the resting potential is caused by what? - chemical and electrical gradients both going into the cell - a chemical gradient going into the cell and an electrical gradient going out of the cell - chemical and electrical gradients both going out of the cell - a chemical gradient going out of the cell and an electrical gradient going into the cell
chemical and electrical gradients both going into the cell
Action potential propagation begins (is first generated at) what region of a neuron? node dendrite initial segment myelin
initial segment
In what part of the neuron does the action potential typically initiate? initial segment of the axon soma (cell body) dendrites axon terminals
initial segment of the axon
The cerebrospinal fluid (CSF) is confined between the __________ and the __________. dura mater; arachnoid mater epidural space; subdural space pia mater; dura mater pia mater; arachnoid mater
pia mater; arachnoid mater
Clenching the fists often enhances the knee jerk reflex. This is an example of __________. positive feedback nerve injury stimulus response reinforcement
reinforcement
Hyperpolarization results from __________. fast closing of voltage-gated K+ channels slow closing of voltage-gated K+ channels slow closing of voltage-gated Na+ channels
slow closing of voltage-gated K+ channels
Injury to this center in the mesencephalon may lead to Parkinson's disease. substantia nigra red nuclei reticular activating system superior colliculi
substantia nigra
Which part of the mesencephalon coordinates reflex eye movements? reticular activating system superior colliculi substantia nigra red nuclei
superior colliculi
Identify the structure at the end of the arrow. the primary motor cortex the motor homunculus the cerebral peduncles the pyramids
the cerebral peduncles
The __________ reflex is a polysynaptic reflex that involves activating muscles contralateral to the receptor. flexor stretch crossed extensor tendon
crossed extensor
In a typical neuron, what is the equilibrium potential for sodium? -90 mV +66 mV -70 mV +30 mV
+66 mV
Ascending and descending tracts can be found in which area(s) of the spinal cord? 4, 5, 6 1, 2, 3 11, 12, 13, 14 8 9
1, 2, 3
What is the magnitude (amplitude) of an action potential? 100 mV 70 mV 30 mV
100 mV
Where do somatic motor neurons reside? 12 9 11 14 13
14
What is the typical duration of a nerve action potential? 20 ms 2 ms 0.2 ms 200 ms
2 ms
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?
4, 6, 7, 1, 2, 3, 5
Where on the neuron is the action potential initiated? Dendrite Axon Cell body Initial segment
Initial segment
Which of the following statements would NOT be considered a mechanism of action of hormones? Adjacent cells coordinate cellular activities by exchanging ions and molecules across gap junctions. Turn an existing enzyme or membrane channel "on" or "off" by changing its shape or structure. Stimulate the synthesis of an enzyme or a structural protein not already present in the cytoplasm by activating appropriate genes in the cell nucleus. Increase or decrease the rate of synthesis of a particular enzyme or other protein by changing the rate of transcription or translation.
Adjacent cells coordinate cellular activities by exchanging ions and molecules across gap junctions.
A reflex arc always includes a(n) __________. sensory receptor sensory neuron motor neuron All of the listed responses are correct.
All of the listed responses are correct.
Compared to type A axons, type C axons are __________. slower propagating smaller diameter unmyelinated All of the listed responses are correct.
All of the listed responses are correct.
During propagation of the action potential, __________. the axon hillock depolarizes the initial segment after threshold is reached, voltage-gated sodium channels open rapidly local currents depolarize a spot adjacent to the active zone All of the listed responses are correct.
All of the listed responses are correct.
Which of these statements about the medulla oblongata is true? It connects the brain and spinal cord. The medulla oblongata relays all communication between the brain and spinal cord. It coordinates complex autonomic functions. All of the listed responses are correct.
All of the listed responses are correct.
Which of these is found in the pons? tracts to the cerebellum nuclei for four cranial nerves respiratory control nuclei All of these are found in the pons.
All of these are found in the pons.
How is an action potential propagated along an axon? Stimuli from the graded (local) potentials from the soma and dendrites depolarize the entire axon. An efflux of potassium from the current action potential depolarizes the adjacent area. An influx of sodium ions from the current action potential depolarizes the adjacent area.
An influx of sodium ions from the current action potential depolarizes the adjacent area.
An example of the brain affecting spinal reflexes is the replacement of the __________ by the __________ at around two years of age. plantar reflex; Babinski sign Babinski sign; flexor reflex flexor reflex; plantar reflex Babinski sign; plantar reflex
Babinski sign; plantar reflex
Dr. Taylor experienced a cerebrovascular accident (CVA), or stroke. Why is stroke dangerous to neurons? - CVAs interfere with the circulation of cerebrospinal fluid (CSF), which disrupts its ability to function in the transport of nutrients, waste, and chemical nutrients to individual neurons. - CVAs affect the permeability of the endothelial cells that create the blood-brain barrier, allowing toxic substances to reach neurons and cause their death. - CVAs disrupt the production and transport of neurotransmitters required for neuronal function and maintenance. - CVAs block the normal blood supply to the brain. Neurons that are starved of oxygen and nutrients begin to die within minutes.
CVAs block the normal blood supply to the brain. Neurons that are starved of oxygen and nutrients begin to die within minutes.
The neurotransmitter glutamate opens channels that are permeable to sodium ions. What effect does glutamate produce on a postsynaptic neuron? neither IPSPs nor EPSPs EPSPs IPSPs both IPSPs and EPSPs
EPSPs
Which of the following statements accurately reflects a difference between ganglia in the sympathetic and parasympathetic divisions? Ganglia of the parasympathetic division are located near the spinal cord, but ganglia of the sympathetic division are located in or near the target organ. The sympathetic and parasympathetic divisions both use ganglia located near the spinal cord and target organs. Ganglia of the sympathetic division are located near the spinal cord, but ganglia of the parasympathetic division are located in or near the target organ. There are no differences between ganglia of the sympathetic and parasympathetic divisions.
Ganglia of the sympathetic division are located near the spinal cord, but ganglia of the parasympathetic division are located in or near the target organ.
________ are chemical messengers that are released by cells and transported in the bloodstream to alter the activities of specific cells in other tissues. Hormones Neuropeptides Antigens Neurotransmitters Humoral antibodies
Hormones
Which of the following is NOT a property of the stretch reflex? Its receptor is a muscle spindle. It is a polysynaptic reflex. It regulates muscle length. It is activated by muscle elongation.
It is a polysynaptic reflex.
Which of these is NOT a property of the epithalamus? It is the roof of the fourth ventricle. It is the location of the choroid plexus. It is the location of the pineal gland. It is the roof of the diencephalon.
It is the roof of the fourth ventricle.
Which of these is NOT a property of the limbic system? It is central to our ability to experience emotions. It is important in learning and memory. It regulates body temperature. It includes the hippocampus.
It regulates body temperature.
Which of the following is true of the endocrine system? It responds slowly but effectively for maintaining homeostatic functions. It responds rapidly to stimuli. It responds specifically to digestive stimuli. It communicates by the release of neurotransmitters. It responds with motor output.
It responds slowly but effectively for maintaining homeostatic functions.
Which anatomical description is TRUE of the sympathetic division of the autonomic nervous system? It is also known as the craniosacral division because of its origins of innervation. Its innervation originates mainly in the thoracic segment of the spinal cord. It has long preganglionic fibers and short postganglionic fibers. Its synapses are mainly located in intramural ganglia, within the tissues of the target organs.
Its innervation originates mainly in the thoracic segment of the spinal cord.
What ion causes repolarization of the neuron during an action potential? Mg2+ (magnesium) K+ (potassium) Na+ (sodium) Ca2+ (calcium)
K+ (potassium)
What ion is responsible for the depolarization of the neuron during an action potential? Na+ (sodium) K+ (potassium) Cl- (chloride) Ca2+ (calcium)
Na+ (sodium)
The concentrations of which two ions are highest outside the cell? - Na+ and protein anions (A−) - K+ and protein anions (A−) - Na+ and Cl− - K+ and Cl−
Na+ and Cl−
Which of these statements about the medulla oblongata is FALSE? It relays sensory and motor information. It lies between the cervical spinal cord and the pons. It contains centers that regulate cardiovascular and respiratory functions. None of the listed responses is correct.
None of the listed responses is correct.
Which of the following best explains why the body "remembers" painful injuries long after they have been healed? - Pain receptors are slow-adapting receptors, so they adapt very slowly to changes in the PNS, such as the healing of an injury. - Fast-adapting receptors quickly signal that your physical position is in the same movement as when you were first injured. - Your sensory receptors implement central adaptation, which allows them to remain active after the stimulus is removed. - Phasic receptors are stimulated by an injury. Once the injury is healed, they "phase" in and out of remembering the injury.
Pain receptors are slow-adapting receptors, so they adapt very slowly to changes in the PNS, such as the healing of an injury.
Which pathway crosses over in the medulla? Posterior column pathway Spinocerebellar pathway Anterior spinothalamic pathway Lateral spinothalamic pathway
Posterior column pathway
A lesion is located at the ventral-most portion of someone's spinal cord. Which sense is most likely to be directly affected? Fine touch Pressure Pain Proprioception
Pressure
How do action potential propagation speeds in myelinated and unmyelinated axons compare? Propagation is faster in unmyelinated axons. Propagation speeds are similar in both axon types. Propagation is faster in myelinated axons. Propagation in myelinated axons is faster over short distances, but slower over long distances.
Propagation is faster in myelinated axons.
Dr. Taylor's CVA occurred in the left cerebral hemisphere, near her language center. If Dr. Taylor's CVA had occurred in the same region of the right cerebral hemisphere, what would have been different about her symptoms? - She would have had difficulty in visual and spatial analysis as well as possible difficulty in identifying familiar objects by touch, taste, and sight. - She would have had difficulty with mathematical calculations. - She would have had difficulty with abstract intellectual functions like predicting the consequences of an event or action. - She would have had difficulty with visual association; for example, she would have been unable to recognize the letters of the alphabet as letters. They would have appeared as unfamiliar symbols.
She would have had difficulty in visual and spatial analysis as well as possible difficulty in identifying familiar objects by touch, taste, and sight.
Why does the action potential only move away from the cell body? The areas that have had the action potential are refractory to a new action potential. The flow of the sodium ions only goes in one direction—away from the cell body
The areas that have had the action potential are refractory to a new action potential.
The sodium-potassium exchange pump transports potassium and sodium ions in which direction(s)? - Sodium ions are transported into the cell. Potassium ions are transported out of the cell. - Sodium ions are transported out of the cell. Potassium ions are transported into the cell. - Sodium and potassium ions are both transported out of the cell. - Sodium and potassium ions are both transported into the cell.
Sodium ions are transported out of the cell. Potassium ions are transported into the cell.
Terry has recently been diagnosed with an inherited form of depression. Which of the following is the most likely cause for the depression? Terry's depression is a result of excessive production of dopamine. Terry is experiencing the destruction of GABA-secreting neurons in the basal nuclei. Terry has a mutation in the enzyme involved in NE synthesis. Terry has an overabundance of serotonin secretion.
Terry has a mutation in the enzyme involved in NE synthesis
Part C - Motor Nerve AnatomyPart complete Damage to which branch of the spinal nerve is likely to have an effect on the muscles of the limbs? Sympathetic nerve The rami communicantes The posterior ramus The anterior ramus
The anterior ramus
What is the last spot where CSF circulates before being resorbed by the circulatory system? A choroid plexus The subarachnoid space The central canal The arachnoid villi The median aperture of the fourth ventricle
The arachnoid villi
When you touch a hot stove, along which pathway will the impulses travel and what is the final destination in the CNS? - the lateral spinothalamic tract, reaching the frontal lobe of the cerebral cortex - The lateral spinothalamic tract would relay these impulses to the parietal lobe(post central gyrus) of the cerebral cortex . - the anterior spinothalamic tract, reaching the parietal lobe(post central gyrus) of the cerebral cortex - the spinocerebellar tract, reaching the parietal lobe of the cerebral cortex
The lateral spinothalamic tract would relay these impulses to the parietal lobe(post central gyrus) of the cerebral cortex .
At rest, why is the transmembrane potential of a neuron (-70 mV) closer to the potassium equilibrium potential (-90 mV) than it is to the sodium equilibrium potential (+66 mV)? - The concentration of potassium ions inside the cell is greater than the concentration of sodium ions outside the cell. - For each ATP hydrolyzed, the sodium-potassium exchange pump transports more sodium ions out of the cell (three) than it transports potassium ions into the cell (two). - There are more negatively charged proteins inside the cell than outside the cell. - The membrane is much more permeable to potassium ions than to sodium ions.
The membrane is much more permeable to potassium ions than to sodium ions.
When reviewing the general functions of the parasympathetic division, which of the following statements best summarizes the physiologic outcome? The parasympathetic division is considered a catabolic system because it functions to make glucose readily available to the cells. The parasympathetic division works at counterbalancing the sympathetic division by conserving energy and lowering metabolic rate. The parasympathetic division mobilizes energy reserves in the liver and skeletal muscle for immediate release. The parasympathetic division functions in short term, physiologic crisis management.
The parasympathetic division works at counterbalancing the sympathetic division by conserving energy and lowering metabolic rate.
Which anatomical description is true of the parasympathetic division of the autonomic nervous system? The preganglionic fibers and postganglionic fibers synapse in the ganglia, which are located in the tissues of the target organs. Its innervation originates mainly in the thoracic segment of the spinal cord. It has short preganglionic fibers and long postganglionic fibers. Ganglia of the parasympathetic division are located near the spinal cord.
The preganglionic fibers and postganglionic fibers synapse in the ganglia, which are located in the tissues of the target organs.
The ANS consists of two divisions: the sympathetic and the parasympathetic. Which statement best describes the organization of the sympathetic division's preganglionic neurons? The sympathetic preganglionic neurons are located in the spinal cord in the lumbar and sacral regions L2-S4. The preganglionic neurons are located in the thoracic and lumbar regions of the spinal cord. The sympathetic preganglionic neurons are located in the brain stem and in the spinal cord in the sacral regions S2-S4. The sympathetic preganglionic neurons are located in the brain stem and in the spinal cord in the regions C2-C6.
The preganglionic neurons are located in the thoracic and lumbar regions of the spinal cord.
In an unmyelinated axon, why doesn't the action potential suddenly "double back" and start propagating in the opposite direction? New action potential generation near the soma repels previously generated action potentials. The previous axonal segment is refractory. Positive charges only move in one direction. The extracellular sodium concentration is too low around the previous axonal segment for an action potential to be (re)generated.
The previous axonal segment is refractory.
Which answer best describes the relative refractory period in the neuron? The neuron's membrane potential is -70 mV. The neuron cannot generate another action potential under extreme stimulation. The resting membrane potential is in the process of being restored, but concentrations of sodium and potassium are not back to their original state. Potassium ions are entering the neuron through open membrane channels.
The resting membrane potential is in the process of being restored, but concentrations of sodium and potassium are not back to their original state.
Which of the following is not true regarding target cells? If a target cell lacks receptors for a hormone then it cannot bind that hormone. They have receptors for a specific hormone. They can be anywhere in the body. They can respond to more than one hormone if they have receptors for each one. They are associated with synapses.
They are associated with synapses.
During an action potential, after the membrane potential reaches +30 mV, which event(s) primarily affect(s) the membrane potential? - Voltage-gated sodium channels begin to inactivate (close) and the sodium-potassium exchange pump begins removing the excess sodium ions from the inside of the cell. - Voltage-gated sodium channels begin to inactivate (close) and voltage-gated potassium channels begin to open. - Voltage-gated sodium channels begin to inactivate (close). - Voltage-gated potassium channels begin to open and the sodium-potassium exchange pump begins removing the excess Na+ ions from the inside of the cell.
Voltage-gated sodium channels begin to inactivate (close) and voltage-gated potassium channels begin to open.
Tim has suffered a vasovagal loss of consciousness, commonly known as fainting. Environmental triggers, including the smell of the anatomy lab and the sight of the cadaver, caused a momentary malfunction of his autonomic nervous system (ANS). How is the structural organization of the ANS different from or similar to that of the somatic nervous system (SNS)? They are different. In the ANS, central nervous system motor neurons synapse with and exert direct control over the visceral effectors. They are different. In the ANS, motor neurons of the central nervous system do not directly control visceral effectors. They synapse with visceral motor neurons in ganglia, and the ganglionic neurons control the visceral effectors. Both the ANS and the SNS have the same organization: an upper motor neuron that synapses with a lower motor neuron that directly innervates muscle. Both the ANS and the SNS have the same organization: a visceral motor neuron that synapses with a preganglionic neuron that synapses with the ganglionic neuron that innervates the visceral effectors.
They are different. In the ANS, motor neurons of the central nervous system do not directly control visceral effectors. They synapse with visceral motor neurons in ganglia, and the ganglionic neurons control the visceral effectors.
Which of the following is NOT a function of cerebrospinal fluid (CSF)? Cushion the brain Remove waste from brain cells Transport blood to brain structures Support the weight of the brain
Transport blood to brain structures
What type of information is communicated through the anterior root of the spinal cord? Visceral sensory Visceral motor Somatic sensory Somatic motor
Visceral motor; Somatic motor
Which of the following channels is most directly responsible for the properties of the axon that lead to action potential generation? Leak potassium channels Leak sodium channels Voltage-gated potassium channels Chemically-gated sodium channels Chemically-gated potassium channels Voltage-gated sodium channels
Voltage-gated sodium channels
What happens just after an axon is depolarized to threshold? Some potassium channels open. Chemically-gated sodium channels open. Voltage-gated sodium channels open. All potassium channels open.
Voltage-gated sodium channels open.
Multiple sclerosis (MS) is a disease that stops action potential propagation by destroying the myelin around (normally) myelinated axons. Which of the following best describes how MS stops action potential propagation? Without myelin, the internode membrane resistance decreases, preventing local currents from reaching adjacent nodes. Without myelin, the node membrane more easily becomes refractory. Without myelin, the internode membrane is depolarized more easily. Without myelin, the internode membrane resistance increases, preventing local currents from reaching adjacent nodes.
Without myelin, the internode membrane resistance decreases, preventing local currents from reaching adjacent nodes.
The electrochemical gradient for potassium ions when the transmembrane potential is at the resting potential (-70 mV) is caused by what? - chemical and electrical gradients both going into the cell - a chemical gradient going out of the cell and an electrical gradient going into the cell - chemical and electrical gradients both going out of the cell - a chemical gradient going into the cell and an electrical gradient going out of the cell
a chemical gradient going out of the cell and an electrical gradient going into the cell
The velocity of the action potential is fastest in which of the following axons? a small unmyelinated axon a large unmyelinated axon a small myelinated axon
a small myelinated axon
Which division of the PNS would contain sensory nerve fibers from special sensory receptors? sympathetic afferent parasympathetic efferent
afferent
Compared the endocrine system, the nervous system is __________. briefer in action more rapidly acting more localized in action all of the listed characteristics
all of the listed characteristics
A hormone might inactivate glucose so it cannot be used by a cell. alter a membrane channel by changing its shape, thereby affecting what can go through it. depolarize a skeletal muscle cell. interfere with norepinephrine at a neuronal synapse. block the production of a cell membrane.
alter a membrane channel by changing its shape, thereby affecting what can go through it.
When a memory brings about a strong emotional response, this is made possible by the __________ of the limbic system. hippocampus fornix pineal gland amygdala
amygdala
Which of the following would NOT be an example of a structural or functional change associated with aging? an increase in brain blood flow due to a weakening of the blood-brain barrier as a function of aging loss of secondary memory recall as a function of aging a loss of synaptic connections due to a decrease in neurotransmitter production a decrease in the volume of the cerebral cortex, with the subarachnoid space becoming larger
an increase in brain blood flow due to a weakening of the blood-brain barrier as a function of aging
Identify the structure labeled "9." anterior white column anterior median fissure anterior white horn anterior white commissure anterior gray commissure
anterior gray commissure
What most directly causes the exocytosis of Ach in synaptic vesicles? depolarization of the membrane at the axon terminal active transport of calcium ions out of the axon terminal arrival of calcium ions in the axon terminal arrival of an action potential at the presynaptic terminal
arrival of calcium ions in the axon terminal
Where are action potentials regenerated as they propagate along an unmyelinated axon? at the internodes at every segment of the axon at myelin at the nodes
at every segment of the axon
Where are action potentials regenerated as they propagate along a myelinated axon? at myelin at the internodes at every segment of the axon at the nodes
at the nodes
When a neuron communicates with another at a synapse on a dendrite, this is called an __________ synapse. axodendritic axoterminal axoaxonic axosomatic
axodendritic
The simplest level of information processing takes place at the __________. axon hillock dendrites soma axon terminals
axon hillock
Where in the neuron is an action potential initially generated? - soma and dendrites - axon hillock - anywhere on the axon
axon hillock
Resynthesis of ACh occurs in the __________. synapse axon axon terminal cell body
axon terminal
Which parts of the somatic nervous system are responsible for coordinating and providing feedback on muscle contractions? basal nuclei and cerebellum medial and lateral pathways spinothalamic pathway posterior column pathway
basal nuclei and cerebellum
If an individual is asked to solve a complex math problem when being monitored for electrical activity in his brain. What type of brain waves would be seen in a normal individual? beta waves theta waves delta waves alpha waves
beta waves
The spinal ganglia consist of __________. cell bodies of sensory neurons axons of motor neurons cell bodies of motor neurons axons of sensory neurons
cell bodies of sensory neurons
Typical CNS neurons are amitotic due to the absence of what structure? ribosomes centrioles axons dendrites
centrioles
Making rapid postural adjustments is a major function of the __________. diencephalon cerebrum cerebellum medulla oblongata
cerebellum
The center in the medulla oblongata where the first synapse in the auditory pathway is made is the __________. cochlear nucleus respiratory rhythmicity center vestibular nucleus reticular formation
cochlear nucleus
In order to communicate with multiple cells at the same time, an axon may branch along its length, producing side branches called __________. telodendria initial segment axon terminal collaterals
collaterals
Dr. Taylor bled into her left cerebral hemisphere. What is the function of the cerebrum? - conscious thought processes, intellectual functions, memory storage and processing, and conscious/subconscious control of skeletal muscle - coordinates complex somatic motor patterns and adjusts the output of other somatic motor centers - controls emotions, has autonomic functions, and functions in hormone productions in addition to being a center for the relay and processing of sensory information - processes visual and auditory data, generates reflexive somatic motor responses, and maintains consciousness
conscious thought processes, intellectual functions, memory storage and processing, and conscious/subconscious control of skeletal muscle
Which principal descending motor pathway provides conscious control over voluntary muscle movements? posterior column pathway spinothalamic pathway spinocerebellar pathway corticospinal pathway
corticospinal pathway
Which of these neural injuries will the corneal reflex NOT test for? damage to cranial nerve V damage to cranial nerve II detection of a corneal contact stimulus damage to cranial nerve VII
damage to cranial nerve II
Which brain region contains centers for processing sensory information, emotions, and hormone production? cerebrum diencephalon mesencephalon cerebellum
diencephalon
Which structure is indicated by the arrow? somatic sensory nuclei ventral root posterior gray horns dorsal root ganglion
dorsal root ganglion
The connective tissue layer that covers Schwann cells is the __________. perineurium epineurium endoneurium endomysium
endoneurium
What type of membrane transport causes the depolarization phase of the action potential in neurons? active transport facilitated diffusion filtration simple diffusion
facilitated diffusion
The dural fold that divides the two cerebellar hemispheres is the __________. tentorium cerebelli falx cerebelli falx cerebri inferior sagittal sinus
falx cerebelli
If EPSPs summate to a sustained value above threshold, then the initial segment will __________. be inhibited generate a string of action potentials generate larger than normal action potentials hyperpolarize
generate a string of action potentials
A typical spinal nerve has a __________ ramus communicans consisting of unmyelinated axons that innervate glands and smooth muscles. posterior anterior gray white
gray
In contrast to the internodes of a myelinated axon, the nodes __________. have lower membrane resistance to ion movement have higher membrane resistance to ion movement are wrapped in myelin only occur at the beginning and end of the axon
have lower membrane resistance to ion movement
The six projections from the gray matter seen in cross-sections of the spinal cord are called __________. horns pyramids tracts flares
horns
There are five steps in the typical reflex arc. Which of the following best describes the activity of the third step? activation of a motor neuron response of a peripheral effector organ information processing within the CNS stimulation of a receptor activation of a sensory neuron
information processing within the CNS
If a nerve impulse was transmitted to the central nervous system (CNS) on a C fiber, __________. it would lead to a slow sensation of cold it would lead to a quick sensation of pain it would lead to a slow sensation of pain it would lead to a quick sensation of cold
it would lead to a slow sensation of pain
Which type of ion channel is always open? leak mechanically-gated chemically-gated voltage-gated
leak
The pons exchanges information with the cerebellum over the __________. The pons exchanges information with the cerebellum over all of these structures. middle cerebellar peduncle inferior cerebellar peduncle superior cerebellar peduncle
middle cerebellar peduncle
A reflex that involves only a sensory neuron and a motor neuron is a _________. crossed extensor reflex monosynaptic reflex polysynaptic reflex disynaptic reflex
monosynaptic reflex
Most CNS neurons fall into which structural category? unipolar anaxonic multipolar bipolar
multipolar
Neural circuits occur in all of these patterns EXCEPT __________. convergent divergent reverberating multipolar
multipolar
Which of these is absent in the gray matter of the spinal cord? dendrites unmyelinated axons myelinated axons neuroglia
myelinated axons
Saltatory propagation occurs in _________ axons, in which action potentials _________. - unmyelinated; spread by depolarizing the adjacent region of the axon membrane - unmyelinated; move from one node of Ranvier to another - myelinated; move from one node of Ranvier to another - myelinated; move continuously along the axon toward the axon hillock
myelinated; move from one node of Ranvier to another
Which of these neurotransmitters does NOT bind to a plasma membrane receptor? nitric oxide GABA serotonin norepinephrine
nitric oxide
Which of these neurotransmitters is released at CNS adrenergic synapses? adrenaline serotonin norepinephrine GABA
norepinephrine
Let's consider a scenario in which the resting membrane potential changes from −−70 mVmV to +70 mVmV, but the concentrations of all ions in the intracellular and extracellular fluids are unchanged. Predict how this change in membrane potential affects the movement of Na+Na+. The electrical gradient for Na+Na+ would tend to move Na+Na+ __________ while the chemical gradient for Na+Na+ would tend to move Na+Na+ __________. - out; in - in; in - out; out - in; out
out; in
The primary somatosensory cortex is found on the __________. postcentral gyrus frontal lobe precentral gyrus cingulate gyrus
postcentral gyrus
The __________ gray horns contain somatic and visceral sensory nuclei. lateral intermediate anterior posterior
posterior
Identify the structure labeled "4." posterior gray horn posterior gray ganglion anterior gray horn posterior gray column posterior white column
posterior gray horn
Which structure is indicated by the arrow? posterior gray horns dorsal root ganglion anterior gray horn ventral root
posterior gray horns
Identify the structure labeled "1." median commissure lateral white horn lateral white column posterior white column anterior white column
posterior white column
What causes repolarization of the membrane potential during the action potential of a neuron? sodium efflux (leaving the cell) sodium influx (entering the cell) potassium efflux (leaving the cell) potassium influx (entering the cell)
potassium efflux (leaving the cell)
The most abundant intracellular cation is __________, while the most abundant extracellular anion is __________. sodium, protein anions sodium, chloride potassium, chloride potassium, protein anions
potassium, chloride
The neurotransmitter GABA blocks presynaptic voltage-gated calcium channels. Consequently, GABA produces __________. EPSPs presynaptic facilitation IPSPs presynaptic inhibition
presynaptic inhibition
You are working on a new medication to selectively kill cancer cells. You test the drug on a culture of normal neurons to check for any side effects. Despite the presence of the drug, a normal resting membrane potential of −−70 mVmV is maintained. Look at each of the figures below to analyze how the drug might be affecting the neuron. Figure A shows neuron activity under normal, or control, conditions (without the drug). Figure B shows neuron activity that has been altered due to exposure to the drug. Based on these results, the drug is most likely __________. - destroying some of the K+ leak channels - preventing Na+-gated channels from opening - destroying some of the Na+ leak channels - opening voltage-gated K+ channels
preventing Na+-gated channels from opening
In a spinal reflex, information flows from __________ to __________ to __________. spinal cord; peripheral effector; brain spinal cord; brain; receptor receptor; spinal cord; peripheral effector receptor; sensory neuron, spinal cord
receptor; spinal cord; peripheral effector
Neuroglia perform all of these functions EXCEPT __________. regulate extracellular fluid composition secrete CSF provide supportive framework release neurotransmitters
release neurotransmitters
Endocrine cells release their secretions onto an epithelial surface. release their secretions directly into body fluids such as blood. are modified connective tissue cells. contain few vesicles. are a type of nerve cell.
release their secretions directly into body fluids such as blood.
When Tim fainted, the sympathetic division of the ANS failed him, while the parasympathetic division went into overdrive. Parasympathetic stimulation of the vagus nerve caused Tim's heart rate to slow, the force of contractions to decrease, and his blood pressure to drop. As a result, blood flow to the brain decreased, causing the fainting episode. Which part of the brain is critical for maintaining consciousness through its interactions with the cortex? general interpretive center reticular activating system limbic system nucleus basalis
reticular activating system
The node-to-node "jumping" regeneration of an action potential along a myelinated axon is called __________. saltatory propagation myelinated propagation local propagation continuous propagation
saltatory propagation
Which of these types of neuroglia are abundant in peripheral ganglia? satellite cells oligodendrocytes astrocytes microglia
satellite cells
Which of the following is an example of an autocrine communication? the direct transmission of an action potential from one cardiac muscle fiber to another cardiac muscle fiber the secretion of a thyrotropin (TSH) from the anterior pituitary gland into the blood where it travels to the cells of the thyroid gland smooth muscle cells secreting prostaglandins that cause contraction of the smooth muscle cells the secretion of inhibitory neurotransmitters from a photoreceptor cell to nearby bipolar cells in the retina
smooth muscle cells secreting prostaglandins that cause contraction of the smooth muscle cells
The movement of what ion is responsible for the local currents that depolarize other regions of the axon to threshold? sodium (Na+) Potassium (K+) calcium (Ca2+) voltage-gated sodium (Na+) channels
sodium (Na+)
The areas of Michael's brain that were injured during his birth affected his control over his voluntary movements. Which part of the nervous system distributes motor commands to skeletal muscles? parasympathetic nervous system autonomic nervous system sympathetic nervous system somatic nervous system
somatic nervous system
What is the function of the structure labeled "11"? somatic sensory receiving visceral motor control ascending pathway visceral sensory receiving somatic motor control
somatic sensory receiving
The __________ is part of the central nervous system (CNS) and the __________ is part of the peripheral nervous system (PNS). brain; spinal cord spinal nerve; spinal cord cranial nerve; spinal nerve spinal cord; spinal nerve
spinal cord; spinal nerve
Which of the following tactile receptors is found in the dermal papillae? tactile disc tactile corpuscle ruffini corpuscle free nerve endings
tactile corpuscle
The cerebrum develops from the embryonic __________. diencephalon mesencephalon telencephalon metencephalon
telencephalon
Which embryological brain vesicle will form the cerebrum? metencephalon mesencephalon myelencephalon telencephalon
telencephalon
The region of cerebral cortex inferior to the lateral sulcus is the __________ lobe. temporal occipital parietal frontal
temporal
The polysynaptic reflex that limits muscle tension is the __________ reflex. postural tendon stretch flexor
tendon
Anesthetics administered into the epidural space are advantageous because __________. the effects are long lasting, even with just a single injection the effect is localized and only sensory the patient experiences both sensory loss and paralysis temporarily the effect can easily be carried throughout the spinal cord region by way of cerebrospinal fluid
the effect is localized and only sensory
If you are reading and you unexpectedly hear a loud noise, your head generally snaps up. Which portion of the midbrain is most likely to be responsible for this reflexive motion? the red nucleus the superior colliculus the inferior colliculus the substantia nigra
the inferior colliculus
The repolarization phase of an action potential results from __________. the opening of voltage-gated K+ channels the opening of voltage-gated Na+ channels the closing of voltage-gated K+ channels the closing of voltage-gated Na+ channels
the opening of voltage-gated K+ channels
In a neuron, sodium and potassium concentrations are maintained by the sodium-potassium exchange pump such that __________. - the concentration of sodium outside the cell is equal to the concentration of potassium inside the cell. - both sodium and potassium concentrations are higher outside the cell compared to inside. - the sodium concentration is higher outside the cell than inside the cell and the potassium concentration is higher inside the cell than outside the cell. - the sodium concentration is higher inside the cell than outside the cell and the potassium concentration is higher outside the cell than inside the cell.
the sodium concentration is higher outside the cell than inside the cell and the potassium concentration is higher inside the cell than outside the cell.
What is the electrochemical gradient of an ion? - the difference between the concentrations of an ion inside and outside the cell - the sum of the electrical and chemical gradients for that ion - the transmembrane potential at which the electrical and chemical gradients are equal in magnitude, but opposite in direction - The electrochemical gradient is the direction an ion would diffuse (either outward or inward) when the neuron is at rest, regardless of the transmembrane potential.
the sum of the electrical and chemical gradients for that ion
Which of the following is NOT a component of the spinocerebellar pathway? the thalamus the pons the lateral white column of the spinal cord the medulla oblongata
the thalamus
During an action potential of a neuron, what directly causes the different channels to open and close? Sodium and potassium ions calcium ions the transmembrane potential (voltage) neurotransmitter binding to chemically gated channels
the transmembrane potential (voltage)
Shingles that manifest themselves in close proximity to the umbilical region stem from an infection within spinal nerves emerging from which spinal segments? lumbar sacral thoracic cervical
thoracic
Which of the following is a function of the hypothalamus? to regulate body temperature to secrete cerebrospinal fluid (CSF) to process and transmit visual information secretes melatonin
to regulate body temperature
Which of the following target organs will have its parasympathetic regulation impacted by damage to the sacral region of the spinal cord? heart urinary bladder salivary glands stomach
urinary bladder
Which structure is indicated by the arrow? dorsal root ganglion posterior gray horns somatic sensory nuclei ventral root
ventral root
Which principal descending motor pathway primarily controls muscle tone and balance? vestibulospinal tract of the medial pathway reticulospinal tract of the medial pathway cuneate fasciculus of the posterior column pathway anterior spinothalamic tracts
vestibulospinal tract of the medial pathway
A reflex that leads to secretion of saliva is a(n) __________ reflex. somatic visceral acquired stretch
visceral
The depolarization phase of an action potential results from the opening of which channels? voltage-gated Na+ channels voltage-gated K+ channels chemically gated Na+ channels chemically gated K+ channels
voltage-gated Na+ channels
The generation of an action potential in a neuron requires the presence what type of membrane channels? - voltage-gated channels - leakage channels - chemically gated channels - membrane channels are not required
voltage-gated channels
What is primarily responsible for the brief hyperpolarization near the end of the action potential? the sodium/potassium exchange pump taking some time to restore the normal ion concentrations voltage-gated potassium channels opening as the membrane potential becomes more negative (repolarized) voltage-gated sodium channels taking some time to recover from inactivation voltage-gated potassium channels taking some time to close in response to the negative membrane potential
voltage-gated potassium channels taking some time to close in response to the negative membrane potential
Where are the parasympathetic ganglionic synapses for the heart located? in the otic ganglion in the celiac ganglion within the heart itself in the ciliary ganglion
within the heart itself
