AP Unit 2 practice test

The sodium-potassium (Na-K) pump moves:
both Na+ and K+ against their concentration gradients ([L] to [H])
An inhibitory postsynaptic potential (IPSP) is associated with (choose all correct):
-hyperpolarization of the membrane.
– opening of potassium (K+) channels.
– raising the amount of depolarizing change/stimulus for a local potential needed to generate an action potential.
The gap between adjacent Schwann cells where
the neurolemma is exposed is called a ________.
node of Ranvier
Voltage is always measured between two points and the difference in electrical charge (+ and -) may be called the electrical potential between the two points.
true
A group of nerve cell bodies located in the precentral gyrus represents the origin (beginning) of a neural pathway. The tract associated with this group of neurons would be:
a descending tract (motor tract)
The all-or-none phenomenon as applied to nerve cell conduction states that the entire nerve cell must be stimulated to generate an action potential.
false
Which of the following is a neuron that conducts nervous impulses away from the CNS to a muscle or a gland?
efferent
Local potentials represent graded (variable) changes in membrane polarity from the resting membrane potential or level; action potentials, on the other hand, are “all-or-none” in terms of their change in membrane polarity.
true
The brain and spinal cord comprise the:
central nervous system
The central sulcus separates which lobes of the cerebrum?
frontal and parietal
Which of the following represents “a group (i.e., a bundle) of myelinated axons traveling together within the CNS?”
tract
The part of a neuron that conducts impulses away from its cell body is called a(n) ______.
axon
If bacteria invaded the brain or spinal cord, microglia would migrate to the site of infection to engulf the bacteria.
true
Nerve impulses from many different stimulatory presynaptic neurons traveling to one postsynaptic neuron may all arrive
there at the same time. Which of the following relates to that phenomenon/process?
spatial summation
A “shallow groove” in the gray matter on the outer surface of the cerebrum (i.e., cerebral cortex) is called a gyrus.
False
The brain stem consists of the:
pons, midbrain, and medulla oblongata
Cerebrospinal fluid is formed by:
choroid plexus
When an action potential is initiated on a nerve cell membrane, it radiates and is propagated in all directions from the point of initial stimulation.
True
Synaptic vesicles are located:
in the axon of the presynaptic neuron.
The role of acetylcholinesterase is to __________.
to destroy acetylcholine shortly after it is released at a synapse
Which is NOT necessary for the normal function of a spinal reflex arc?
cerebral cortex
Chemical neurotransmitters that increase the _____ membrane’s permeability to sodium ions exhibit _____ effects.
postsynaptic, excitatory
The part of the brain that controls the endocrine system, including the master gland of the endocrine system, is the hypothalamus.
True
The spinal cord (i.e., the conus medullaris) ends in the upper lumbar region (around L1 to L2 vertebrae).
True
Ascending nerve tracts can be subdivided functionally as sensory or motor.
False
A small nerve is a(n):
organ
How many organs comprise the peripheral nervous system?
many thousands, if not more (if one considers the smallest of nerves)
Cholinergic receptors are classified as either muscarinic or nicotinic receptors
True
How many pairs of cranial nerves occur in humans?
12
The parasympathetic division of the autonomic nervous system has been nicknamed the “rest & digest division,” because it is particularly active when we are quietly resting and digesting our food.
True
Postganglionic fibers of sympathetic pathways secrete _________ and postganglionic fibers of parasympathetic pathways secrete __________.
acetylcholine / norepinephrine
If the dorsal root of a spinal nerve was cut, the result in the region served by that spinal nerve would be a complete loss of any sensations (i.e., a “feeling of numbness” in that region).
True
Which one of the following would be part of the peripheral nervous system?
dorsal root ganglion
If norepinephrine binds to an adrenergic beta receptor on cardiac muscle fibers, the heart will race (increase its rate of beating).
True
The “chain ganglia” (also known as “paravertebral ganglia”) are part of the ________ and contain ________.
sympathetic nervous system / nerve cell bodies of postganglionic fibers
The connective tissue layer that surrounds a fascicle within a nerve is called the:
perineurium
The sympathetic nervous system would do all of the following, except:
constrict the pupil of the eye.
Autonomic efferent (motor) pathways generally consist of ___________ neuron(s).
two
A large percentages of our internal organs that contain smooth or cardiac muscle are innervated both by sympathetic fibers and parasympathetic fibers.
True
What part of many spinal nerves becomes involved with the formation of plexuses in several places along the spinal cord?
ventral ramus
Which of the following would NOT occur if the parasympathetic division was more active than the sympathetic division?
heart rate would increase
Preganglionic fibers of both the sympathetic and parasympathetic divisions of the autonomic nervous system generally are myelinated.
True
Which spinal nerve exits the spinal cord and vertebral column between C7 and T1 vertebrae?
C8
Preganglionic fibers of sympathetic pathways secrete _________ and preganglionic fibers of parasympathetic pathways secrete __________.
acetylcholine / acetylcholine
The sympathetic division of the autonomic nervous system is also called the “thoraco-lumbar division,” because it is formed by branches of T1 through T12 (thoracic) and L1 and L2 (upper lumbar) spinal nerves.
True
Where would the nerve cell bodies of the postganglionic, parasympathetic efferent fibers be located?
in ganglia on or within the organ innervated
Which of the following does not describe the ANS?
a system of motor neurons that innervates all muscle cells
Promoting maintenance activities and conserving body energy is the role of the:
parasympathetic nervous system
Sympathetic nerves may leave the spinal cord at which vertebra?
first thoracic
Cardiovascular effects of the sympathetic division include all except ________.
dilation of the blood vessels serving the skin and digestive viscera
The somatic and autonomic nervous systems differ in all of the following except ________.
all of the neurotransmitters
Which of the following statements is not true?
Sympathetic origin is craniosacral; parasympathetic is thoracolumbar.
Which of the following are functions of astrocytes? (Select all that apply)
– Support and brace neurons
-Control the chemical environment around neurons
Which of the following describes the nervous system sensory function?
Senses change in the environment
Which of the following is not characteristic of neurons?
They are mitotic
Which of the choices below describes the ANS?
Motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle and glands
Oligodendrocytes are functionally similar to:
Schwann cells
A neuron that carries impulses away from the CNS to effector organs is an:
efferent neuron
The resting membrane potential is generated by: (select all that apply)
-differences in ionic makeup of ICF and ECF
-differences in permeability of the plasma membrane
At rest the plasma membrane is more permeable to:
potassium
When the interior of the cell becomes more negative, decreasing the chance of producing a nerve impulse it is called:
hyperpolarization
Which ion channel opens in response to a change in the membrane potential and participates in the generation and conduction of action potentials?
voltage gated channels
Immediately after an action potential has peaked, which cellular gates open?
potassium
Collections of nerve cell bodies in the central nervous system are called:
nuclei
Which of the following is false or incorrect?
A nerve impulse occurs if the excitatory and inhibitory effects are equal
Saltatory conduction is made possible by:
myelin sheath
What structure is specialized for release and reception of neurotransmitters?
Chemical synapse
What type of membrane potential is generated at the synapse on the postsynaptic membrane?
graded potential
When a postsynaptic neuron is stimulated by a large number of terminals at the same time this results in:
spatial summation
The time period when a neuron cannot respond to another stimulus is the:
absolute refractory period
A ridge on the surface of the cortex is called a:
gyrus
Which functional area of the cerebral cortex receives general sensory information from the skin and proprioceptors?
primary somatosensory cortex
Which white matter tracts connect the adjacent areas of the cerebral cortex in the same hemisphere?
association fibers
What structure is described as the gateway to the cerebral cortex?
thalamus
What structure is described as a bridge, relaying impulses from the motor cortex and cerebellum?
pons
The connective tissue membranes that cover and protect the central nervous system include:
pia mater, arachnoid mater, dura mater
Which of the following is not a function of the CSF?
initiation of some nerve impulses
The adult spinal cord ends between L1 and L2.
true
Cell bodies of the sensory neurons of the spinal nerves are located in ________.
the dorsal root ganglia of the spinal cord
Most of the ascending and descending pathways to and from the brain cross over from one side of the body to the other, this is called:
decussation
Myelinated and unmyelinated nerve fibers are located in the:
white matter of the spinal cord
In ascending pathways there are no third-order neurons in the cerebellum.
True
After axonal injury, regeneration in peripheral nerves is guided by:
Schwann Cells
Dorsal and ventral rami are similar in that they both contain sensory and motor fibers.
True
Reflexes that result from practice or repetition are called:
learned reflexes
The knee jerk reflex is an example of a:
stretch reflex
What connective tissue sheath surrounds the fascicle of a nerve?
perineurium
A major nerve of the sacral plexus is the:
sciatic nerve
Fibers that enter and leave the sympathetic chain without synapsing form structures called ________.
splanchnic nerves
visceral reflex arcs differ from somatic in that ________.
visceral arcs involve two motor neurons
In the parasympathetic nervous system preganglionic fibers synapse with postganglionic fibers in:
terminal ganglia
The rami communicantes are associated only with the sympathetic division of the ANS.
true
Acetylcholine-releasing fibers are called cholinergic fibers.
true
The autonomic nervous system may cause activation or inhibition, depending on the division that is active and the target that is affected.
true