anatomy exam 4 questions
Which of the neuroglial cell types shown are found in the peripheral nervous system (PNS)?
E The cell shown in E wraps and insulates the soma of neurons within ganglia in the PNS
Which of the following is the best description of the function of region B?
Region B includes neurons whose axons carry motor commands from the cerebrum. Region B is the precentral gyrus, the location of the primary (somatic) motor cortex. This is the origin of the descending corticospinal (pyramidal) tracts.
After Joe has a stroke, his doctor asks Joe to touch his right pointer finger to his chin, but Joe is unable to move his right hand. However, when the doctor stimulates Joe's pointer finger with a painful stimulus, Joe's muscles quickly move his hand away from the stimulus. The doctor concludes that ______.
Review central nervous system control of voluntary skeletal muscle contractions and compare it to reflex arc activation.
A patient reports that she has become completely deaf; she can't hear anything. Thorough tests on her ears indicate that her ears have not been damaged. Additional tests reveal that her deafness has been caused by damage to her ______.
Review the different sensory cortices of the parietal and temporal lobes of the brain.
Which motor area both has a homunculus and has descending projection fibers?
The primary motor cortex has projections for the entire human body map, or homunculus. Axons from the primary motor cortex project from the frontal lobe to the spinal cord.
What is the basic condition when a neuron is described as polarized?
There is a separation of positive and negative charges across a membrane. Polarization describes a condition where there is some sorting into poles. In a neuron, the inside of the cell is slightly negative compared to the positive charge (provided primarily by Na+) outside of the cell.
nferior point of termination of the spinal cord in an adult
connus medullaris
The fibers indicated by B are most associated with which structure(s)?
corpus callosum The corpus callosum is the most prominent example of tracts that connect the left and right cerebral hemispheres.
Which of these would you NOT find in the cerebral cortex?
fiber tracts
Which part of the CNS sorts almost all sensory information ascending to the cerebral cortex?
thalamus Afferent impulses from all senses and all parts of the body converge on the thalamus and synapse with at least one of its nuclei. The thalamus— which sorts out and edits these afferent signals before relaying them to the appropriate cortical areas—is considered the gateway to the cerebral cortex. In summary, the thalamus plays a key role in mediating sensation, motor activities, cortical arousal, learning, and memory.
Which part of the brain processes inputs received from the cerebral motor cortex, brain stem nuclei, and various sensory receptors, and then uses this information to coordinate balance, posture, and somatic movement problems?
the cerebellum By processing and interpreting impulses from the motor cortex and brain stem nuclei, as well as sensory pathways, the cerebellum provides the precise timing and appropriate patterns of skeletal muscle contraction for the smooth, coordinated movements and agility needed for daily living (e.g., driving, typing, and tying our shoes). It also plays a poorly understood role in cognition. Cerebellar activity occurs subconsciously (we are not aware of it).
You have a patient experiencing an essential tremor, which makes it hard for him to dress and feed himself. Imaging has detected a lesion in the basal nuclei. How would you best explain the function of these cerebral structures to him?
"This group of cells monitors all of our outgoing motor signals and makes sure there isn't any excessive activity. Your injury is preventing them from doing their job." You remembered that one of the primary roles of these nuclei is prevent or inhibit unwanted muscle contractions.
Which of the following statements about the cerebellum is NOT correct?
.The cerebellum generates conscious motor commands (Damage to the cerebellum could affect posture. The cerebellum has a cortex and homunculus, just like the motor cortex. The cerebellum plays a role maintaining your balance)
Which of the neuroglial cell types shown form myelin sheaths within the CNS?
A These cells form myelin sheaths within the white matter of the CNS.
Which of the following is true of axons?
A neuron can have only one axon, but the axon may have occasional branches along its length This is true; a neuron can have only one axon, but the axon may have occasional branches along its length.
Which of the cell types shown helps determine capillary permeability in the CNS?
B Extensions from these cells wrap capillaries and provide extra control over which materials enter or leave the intercellular fluid of the CNS.
Which of the following is true of the cerebral hemispheres of the human brain?
The cerebral hemispheres account for about 83% of total brain mass. The cerebral hemispheres, which form the superior part of the brain, account for about 83% of total brain mass.
Which statement is true of both poliomyelitis and amyotrophic lateral sclerosis (ALS)?
Both conditions are caused by destruction of the ventral horn neurons in the spinal cord. Destruction of neurons in the ventral motor horns of spinal cord gray matter results in paralysis in both conditions
What ion is entering the axon terminal at A, and what effect does it have?
Ca2+, which then causes release of neurotransmitter from the axon terminal Calcium ion channels open when the membrane is depolarized, and the inflow of Ca2+ leads to the release of neurotransmitters from synaptic vesicles
Which of the cell types shown is most associated with the production and flow of cerebrospinal fluid (CSF)?
D These cells line central cavities of the CNS and, in certain places, produce CSF. The cilia of these cells help circulate the CSF that nourishes and cushions the brain and spinal cord.
The effect of acetylcholine can be stimulating or inhibiting. Which of the following gives the best explanation for why this is so?
Different postsynaptic cells will have different receptors.
Your patient's CT scan demonstrates a cerebral vascular accident causing damage to the inferior and posterior portions of her left cerebral hemisphere. Your patient is right-handed. What deficits should you expect?
Difficulty with movement on the right side of her body and difficulty with speech Broca's area, which controls the production of speech is found in the left frontal lobe in 90% of right-handed people. Her primary motor cortex for the right side of her body is in the posterior portion of her left frontal lobe.
Which of the following statements most accurately describes the effect caused by binding of the neurotransmitter (green dots) to the structure labeled C? (image above)
The membrane potential of the postsynaptic membrane changes. Binding of the neurotransmitter to the receptor at C causes the opening of receptor-associated ion channels. Depending on the particular types of channels that open, diffusion of certain ions (typically Na+, K+, or Cl−) will cause a depolarizing or hyperpolarizing effect on the postsynaptic membrane.
Emotional state, rehearsal, association, and automatic memory are all factors that affect the transfer of information from short-term memory (STM) to long-term memory (LTM).
True Many factors can influence the transfer of information from STM to LTM, including emotional state (we learn best when we are alert, motivated, surprised, and aroused), rehearsal (repeating the material enhances memory), association (tying "new" information to "old" information already stored in LTM appears to be important in remembering facts), and automatic memory (some impressions that become part of LTM are subconsciously formed).
What type of event is required for an action potential to be generated?
a threshold level depolarization The axolemma must be depolarized to threshold in order to generate an action potential.
The neuron cannot respond to a second stimulus, no matter how strong
absolute refectory period
Also called a nerve impulse transmitted by axons.
action potential
The meningeal layer resembling spider legs is the
arachnoid mater
Identify the type of tract that communicates between the left prefrontal lobe and the left parietal lobe.
association Association fibers communicate between gyri in the same cerebral hemisphere.
The concentration of ions in the chemical environment surrounding the neurons must be tightly regulated for neurons to function properly. Which of the following cells is most responsible for this?
astrocytes
Which glial cells have the most diversity of function?
astrocytes Astrocytes are the most abundant and diversely functioning glial cells. Examples of their many functions include: anchoring neurons to capillaries, aiding in the exchanges between neurons and blood, guiding the migration of young neurons, and helping control the chemical environment around neurons.
The term central nervous system refers to
brain and spinal cord
What is the groove indicated by C?
central sulcus The central sulcus is the shallow groove that separates the frontal and parietal lobes
Evolutionary development of a head and brain containing neural and sensory organs is a process called
cephalization
White matter is found in all of the following locations EXCEPT the ________.
cerebral cortex
Which part of the brain is the "executive suite" that controls conscious brain activity?
cerebral cortex The cerebral cortex is the "executive suite" of the nervous system, where most of our higher-level decision making occurs. It enables us to be aware of ourselves and our sensations, communicate, remember, understand, and consciously initiate voluntary movements.
Bleeding in the brain, known as a stroke, is more accurately called
cerebrovascular accident
Where nerves serving the upper limbs arise.
cervical enlargement
How would the receptors at C best be classified?
chemically gated The receptors at C are affected by the binding of a chemical neurotransmitter.
What CNS-associated structure is illustrated in this figure?
choroid plexus Note the specific arrangement of glial cells and capillaries as well as the movements of the fluid.
Collection of nerve roots at the inferior end of the vertebral canal.
cuada equina
What is the branch structure
dendrite
The interior of the cell becomes less negative due to an influx of sodium ions.
depolarization
Which of the following events would be directly affected if a neuron had a mutation that prevented the production of voltage-gated Na+ channels?
depolarization leading to action potentials The voltage-gated Na+ channels cause the rapid depolarization phase of the action potential.
What type of cells line the ventricles of the brain?
ependymal
Which type of glial cells are shown in this figure?
ependymal cells Specialized ependymal cells participate in the filtration, absorption, and secretory processes that create cerebrospinal fluid.
The canal connecting the third and fourth ventricles and running through the midbrain is the interventricular foramen.
false
The hypothalamus is the area where afferent impulses from all senses and all parts of the body are sorted out and then relayed to the appropriate area of the sensory cortex
false Afferent impulses from all senses and all parts of the body converge on the thalamus (not the hypothalamus) and synapse with at least one of its nuclei. The thalamus--which sorts out and "edits" these afferent signals before relaying them to the appropriate cortical areas--is considered to be the gateway to the cerebral cortex.
e hypothalamus is the area where afferent impulses from all senses and all parts of the body are sorted out and then relayed to the appropriate area of the sensory cortex
false Afferent impulses from all senses and all parts of the body converge on the thalamus (not the hypothalamus) and synapse with at least one of its nuclei. The thalamus--which sorts out and "edits" these afferent signals before relaying them to the appropriate cortical areas--is considered to be the gateway to the cerebral cortex.
Anchors the spinal cord to the coccyx.
filum terminale
Bipolar neurons are commonly ________
found in the retina of the eye
What does the central nervous system use to determine the strength of a stimulus?
frequency of action potentials
At age 79, Mrs. X is diagnosed with a disorder that severely impairs her logical judgment. Medical imaging techniques show that this has been most likely caused by brain damage in a ______.
frontal lobe The frontal lobe has areas that control voluntary motor functions, mood, smell, and social judgment.
Collections of nerve cell bodies outside the central nervous system are called ________.
ganglia
Which of the following is NOT a correctly matched pair?
gray matter: myelinated axons Gray matter is indicative of unmyelinated axons and cell bodies in the CNS.
When a neurotransmitter like GABA is acting in an inhibitory manner which of the following is likely a result of the GABA acting on the postsynaptic cell?
hyperpolarization of the postsynaptic cell membrane
Loss of function in the enzyme acetylcholine esterase would result in which of the following?
inability to destroy and remove acetylcholine from the synaptic clef
A neuron that has as its primary function the job of connecting other neurons is called a(n)
interneuron
The neural fibers connecting structure A to the cerebral cortex can best be described by which of the following?
interneurons Third-order interneurons in the sensory pathway relay ascending information from the thalamus to specific sensory areas of the cortex.
Which of the following correctly describes a graded potential?
It can have amplitudes of various sizes.
In anterograde amnesia ______.
LTM (long term memory) is not disrupted People with this type of amnesia often cannot remember what they ate for their last meal or events from the immediate past, but retain LTM from before the onset of the anterograde amnesia.
Which of the following is correctly matched?
limbic association area: sense of danger he limbic association area is part of the limbic system, which control our emotions and fears. - posterior association area: understand balance - gustatory cortex; sense of hearing - vestibular cortex; pattern recognition
Vital centers for the control of heart rate, respiration, and blood pressure are located in the
medulla oblongata
Which of the following types of glial cells monitors the health of neurons, and can transform into a special type of macrophage to protect endangered neurons?
microglia Microglial cells are small and ovoid with relatively long "thorny" processes. Their processes touch nearby neurons, monitoring their health, and when they sense that certain neurons are injured or are in other trouble, the microglial cells migrate toward them. Where invading microorganisms or dead neurons are present, the microglial cells transform into a special type of macrophage that phagocytizes the microorganisms or neuronal debris.
The middle primary brain vesicle, the mesencephalon, gives rise to which adult brain structure?
midbrain The term mesencephalon means "midbrain." As it develops from a primary brain vesicle to a secondary brain vesicle and finally an adult brain structure, it retains its name--the midbrain. Each of the other two primary brain vesicles divides to give rise to new secondary brain vesicles and adult brain structures (with new names). Note that encephalo- means "brain."
The brain stem consists of the
midbrain, medulla, and pons
Which of the following does NOT describe conditions that occur during an action potential?
Na+ is used to repolarize the membrane. Initially, K+ leaves the cell through voltage-gated channels. As K+ leaves the cell, the inside of the cell becomes more negative, repolarizing the cell.
Enkephalins and endorphins are peptides that act like
morphine
Name the glial cell at F.
Schwann cell bottom right
Some nerve fibers of the peripheral nervous system have the ability to regenerate after damage has occurred. Which of the following cells is most responsible for aiding in this regulation?
Schwann cells
Which of the following peripheral nervous system (PNS) neuroglia form the myelin sheaths around larger nerve fibers in the PNS?
Schwann cells Schwann cells (also called neurolemmocytes) surround all nerve fibers in the PNS and form myelin sheaths around the larger fibers. Myelin protects and electrically insulates nerve fibers, and it increases the transmission speed of nerve impulses.
Which of these statements is NOT correct regarding our limbic system?
Sights often create strong emotional responses Your sense of smell is more directly attached to your limbic system and is, therefore, more likely to cause emotional responses. (Your amygdala judges facial expressions for danger. Emotional states can alter our blood pressure. The cingulate gyrus helps you express your emotional state.)
Which of the following statements is correct regarding the polarization of a neuronal membrane and the formation of a resting membrane potential?
Sodium/Potassium pumps maintain concentration gradients; sodium and potassium move down their concentration gradients through leakage channels. As Na+ leaks into the cell, the Na+/K+ pump actively transports Na+ back out of the neuron to maintain a gradient for Na+.
Ependymal cells line many open cavities in the central nervous system (CNS). Ependymal cells have cilia on the side of the cell that face these openings. What is the most likely function of these ciliated cells?
movement and circulation of cerebrospinal fluid Yes, cilia are an indication that the cells they appear on are moving fluids past the surface of the cells.
The white matter of the spinal cord contains ________.
myelinated and unmyelinated axons
The interior surface of a neuron's plasma membrane at resting membrane potential will have a ________.
negative charge and contains less sodium than outside of the cell
An individual accidentally transected (cut across) the spinal cord between T1 and L1. This would result in ________.
paraplegia
Nerve impulses are sent to slow the heart's rate of contraction. The nerve fibers sending these signals will most likely belong to which division of the nervous system?
parasympathetic division
During meningitis, which of the following layers is the most likely to be a direct source of pathogens that may spread to the brain?
pia mater The pia mater is meningeal layer closest to the brain
uclei of cranial nerves V (trigeminal), VI (abducens), and VII (facial) are found in the ________.
pons
Which of the following regions of the brain stem carries one-way communications that advise the cerebellum of voluntary motor activities initiated by the motor cortex?
pons The pons is the point at which all information entering or exiting the cerebellum is collected. Descending motor input and ascending sensory input that feed the cerebellum and all cerebellar output enter or exit the cerebellum through several cerebellar peduncles located in the brain stem.
Region A represents which of the following?
prefrontal cortex The prefrontal cortex is located in the anterior region of the frontal lobe.
What cortical region is represented by the area at D?
primary visual cortex The primary visual cortex receives sensory input from the eye via the optic nerves, thalamus, and optic radiations.
For our motor commands to travel toward our muscles, the signals must travel on __________.
projection fibers
Which type of white matter fiber tract connects the cerebrum to lower centers, like the spinal cord?
projection fibers
Which of the following is (are) involved with motor activity (either initiation or coordination)?
red nuclei
Which of the following is NOT a function of the hypothalamus?
regulate the thalamus (regulate body temperature regulate food intake regulate emotional responses)
An exceptionally strong stimulus can trigger a response.
relative refractory period
The specific period during which potassium ions diffuse out of the neuron due to a change in membrane permeability.
repolarization
Which functional area of the brain is responsible for keeping the cortex alert and conscious and enhancing its excitability?
reticular activating system Impulses from all the great ascending sensory tracts synapse within the reticular formation with reticular activating system neurons, keeping them active and enhancing their arousing effect on the cerebrum.
Cranial nerve II, the optic nerve, sends nerve impulses to the brain carrying information about the things we see. These nerve fibers most likely belong to which division of the nervous system?
sensory (afferent) division
Nerve impulses leading to the brain carry information about cool temperatures on the skin. The nerve fibers sending these signals will most likely belong to which division of the nervous system?
sensory (afferent) division
division of the nervous system controls skeletal muscle.
somatic
Nerve impulses leading to the skeletal muscle carry information to direct movement. The nerve fibers sending these signals will most likely belong to which division of the nervous system?
somatic nervous system
What division of the nervous system is most specifically responsible for voluntary motor control?
somatic nervous system The somatic nervous system is composed of somatic motor nerve fibers that conduct impulses from the central nervous system to skeletal muscles. It is often referred to as the voluntary nervous system because it allows us to consciously control our skeletal muscles.
Degeneration of the dopamine-releasing neurons of the ________ is the ultimate cause of Parkinson's disease.
substantia nigra
Which of the following is NOT a diencephalon component?
superior colliculus The superior colliculus is at the inferior border of the diencephalon but is a portion of the brain stem (specifically the midbrain).
During an epileptic seizure, the triggering of convulsions would not directly involve the uncontrolled activity of neurons located in the ______.
thalamus This area of the diencephalon groups and organizes afferent sensory impulses. Convulsions are directly caused by activation of primary motor and/or motor association areas of the cerebral cortex.
The letter A in the figure indicates which of the following structures?
thalmus The letter A indicates the thalamus. Remember that the thalamus is composed of left and right bodies
Cell bodies of sensory neurons are located in ________.
the dorsal root ganglia of the spinal cord
A second nerve impulse cannot be generated until ________.
the membrane potential has been reestablished
The cortical regions indicated by E are involved in what functions?
the production and interpretation of language Regions indicated by E include Broca's area in the frontal lobe and Wernicke's area in the temporal lobe.
As you start working out, you notice that your heart rate and breathing rate start to increase. Which division of your nervous system is generating this response? Be as specific as possible.
the sympathetic division of the autonomic nervous system The sympathetic division of the autonomic, or involuntary, nervous system consists of visceral motor nerve fibers that regulate the activity of smooth muscles, cardiac muscles, and glands. This division is responsible for generating actions required during activity.
Which of the following is NOT a characteristic of neurons?
they are mitotic They conduct impulses. They have extreme longevity. They have an exceptionally high metabolic rate.
A postsynaptic potential is a graded potential that is the result of a neurotransmitter released into the synapse between two neurons.
true
During depolarization, the inside of the neuron's membrane becomes less negative.
true
Embryonic damage to the mesencephalon could result in improper formation of the midbrain.
true
The brain and spinal cord begin as an embryonic structure called the neural plate.
true
Unipolar neurons have axons structurally divided into peripheral and central processes.
true
The term cerebral dominance designates the hemisphere that is dominant for language.
true One cerebral hemisphere or the other "dominates" each of the brain's tasks, and the term cerebral dominance designates the hemisphere that is dominant for language. In most people (about 90%), the left hemisphere has greater control over language abilities, math, and logic.
In general, a primary sensory cortex breaks down sensory input into component parts, while an association cortex makes sense of sensory inputs.
true The primary sensory cortex receives sensory inputs in their cruder forms, while the association cortex helps you understand what the sensory input means.
Which of these materials or structures would be found in greatest amounts or numbers at E?
vesicles containing neurotransmitter Neurotransmitters are released by secretion from the ends of axonal terminals.
Which of the following best describes the hypothalamus?
visceral control center of the bod The hypothalamus is the main visceral control center of the body and is vitally important to overall body homeostasis. Its chief homeostatic roles include controlling the autonomic nervous system; controlling endocrine system function; regulating the sleep-wake cycle, body temperature, hunger, and thirst; and initiating physical responses to emotions.
