Chapter 7, Nervous system

What cells of the nervous system are responsible for anchoring neurons to their blood vessels and controlling the extracellular fluid concentrations of potassium and neurotransmitters?

Astrocytes

What is the magnitude (amplitude) of an action potential?

100mv

How many pairs of cranial nerves branch from the surface of the brain?

12

Which of these is a sympathetic effect?

blood vessels constrict

The midbrain, pons, and medulla oblongata are housed in the ________.

brain stem

Damage to the cervical nerve plexus can cause problems with ________.

breathing

Which of the following is one of the major functions of the pons?

breathing

Ganglia are collections of ______

cell bodies

Hemiplegia and aphasia characterize those patients who have experienced a ________.

cerebrovascular accident (CVA), or stroke

Why is white matter "White"?

It contains a high concentration of myelin.

The spinal cord terminates by vertebra ________.

L3

The hypothalamus is the "emotional-visceral" center of the brain and, thus, is an important part of the ________.

Limbic system

How are the fibers found in the ventral roots of spinal nerves classified?

Motor fibers

Which of the following is a disease of the basal nuclei?

Parkinson's disease

Which of the following neurons is classified as a unipolar neuron?

Sensory Neuron

What is the first event of an action potential?

Sodium gates open and the membrane depolarizes.

what reflexes stimulate skeletal muscle?

Somatic

Which division of the peripheral nervous system activates skeletal muscles?

Somatic nervous system

What portion of the diencephalon acts as a relay station for sensory impulses traveling upward to the sensory cortex?

Thalamus

What statement describes the integrative function of the nervous system?

The central nervous system (CNS) evaluates sensory input and determines if a response is needed.

Which statement describes a function of the spinal cord?

The spinal cord sends sensory information to the brain and carries motor signals from the brain to motor neurons.

Cerebrospinal fluid is reabsorbed into venous blood in the dural sinuses via the ________.

arachnoid granulations

What is the most abundant glial cell in the central nervous system (CNS)?

astrocytes

Which spinal plexus gives rise to the phrenic nerve, and what organ does this nerve supply?

cervical; diaphragm

Binding of a neurotransmitter to its receptors opens __________ channels on the __________ membrane.

chemically gated; postsynaptic

What produces cerebrospinal fluid (CSF)?

choroid plexus

Cerebrospinal fluid is formed from blood by clusters of capillaries in the brain known as ________.

choroid plexuses

What specific part of the midbrain houses reflex centers for vision and hearing?

corpora quadrigemina

Cerebrospinal fluid (CSF) circulates through all of the following EXCEPT ________.

corpus callosum

Which of the following parts of a spinal nerve contains sensory nerves only?

dorsal root ganglion

Which one of the following represents the correct sequence from outermost to innermost layers of the meninges?

dura mater, arachnoid mater, pia mater

During the action potential, when does sodium permeability initially DECREASE?

during the peak of depolarization

Which ciliated neuroglial cell circulates cerebrospinal fluid?

ependymal cells

Which one of the following is the correct sequence in connective tissue sheaths, going from the outermost to the innermost layer?

epineurium, perineurium, endoneurium

A stroke in the primary motor area has caused Don to lose control over his skeletal muscles on the right side of his body. What lobe of his brain was damaged?

frontal lobe

In contrast to the somatic nervous system, the autonomic nervous system ________.

has a chain of two motor neurons

The blockage of cerebrospinal fluid (CSF) outflow in the brain can cause accumulation of fluid, resulting in cranial enlargement in infants. This condition is called __________.

hydrocephalus

Which of these is an effect of the parasympathetic nervous system?

increases peristalsis within the stomach and small intestines

What type of neuron connects sensory and motor neurons in neural pathways?

interneurons

When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron,

ion channels in the plasma membrane of the receiving neuron open.

What fissure separates the two cerebral hemispheres of the brain?

longitudinal fissure

What could result if a spinal nerve is severely damaged?

loss of sensation and flaccid paralysis of the area served by the nerve

The vital centers for the control of visceral activities such as heart rate, breathing, blood pressure, swallowing, and vomiting are located in the ________.

medulla oblongata

The blood-brain barrier is effective against the passage of ________.

metabolic waste such as urea

How are neurons with several processes branching off the cell body, such as motor neurons and interneurons (association neurons), structurally classified?

multipolar

What is the name of cranial nerve III?

oculomotor

Which cranial nerves control movement of the eyes?

oculomotor, trochlear, and abducens

Let's consider a scenario in which the resting membrane potential changes from −70 mV to +70 mV, 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+. The electrical gradient for Na+ would tend to move Na+ __________ while the chemical gradient for Na+ would tend to move Na+ __________.

out and in

In which cerebral lobe is the primary somaticsensory cortex located?

parietal lobe

The ________ is a connective tissue wrapping around fascicles of neuron fibers.

perineurium

The delicate innermost membrane, or meningeal layer, that clings to the surface of the brain and spinal cord is known as the ________ mater.

pia

The ventral rami of the spinal nerves form a complex network of nerves known as a ______

plexus

Sensory receptors located in muscles and tendons are termed ________.

proprioceptors

Each spinal nerve divides into a dorsal and a ventral ________.

ramus

Which of these lists the components of a reflex arc in the correct sequence?

receptor; afferent neuron; control center; efferent neuron; effector

A special group of neurons in the gray matter of the brain stem that plays a role in consciousness and the awake/sleep cycles is the ________.

reticular activating system (RAS)

Nerve impulse transmissions occurring along myelinated neurons are called ________.\

saltatory conduction

What are the two main functional subdivisions of the nervous system?

sensory and motor

Hyperpolarization results from __________.

slow closing of voltage-gated K+ channels

What ion depolarizes the membrane when it diffuses into the axon of a neuron?

sodium

What do the ventral roots and dorsal roots fuse to form?

spinal nerves

What brain dysfunction results when blood supply to a region (or regions) of the brain is blocked and vital brain tissue dies, as by a blood clot or a ruptured blood vessel?

stroke

Which of these parts of the brain is correctly matched with its region?

thalamus; diencephalon

Which of the following is an alternate name for the parasympathetic nervous system?

the craniosacral division

Amal died at the age of 71. If Amal had Alzheimer's disease, what would an autopsy of his brain reveal?

the presence of beta-amyloid plaques, shrunken gyri, and an atrophied brain

If a signal from a sending neuron makes the receiving neuron more negative inside,

the receiving neuron is less likely to generate an action potential

When calcium ions enter the synaptic terminal

they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.

When calcium ions enter the synaptic terminal,

they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.

What part of the central nervous system (CNS) gives rise to sympathetic nerves?

thoracic and lumbar regions of the spinal cord

Sympathetic division fibers leave the spinal cord in the ________.

thoracolumbar region, and the postganglionic fibers secrete norepinephrine

The blood-brain barrier is formed by ________ junctions that nearly seamlessly bind capillaries in the brain.

tight

What cranial nerve pair supplies many organs in the ventral body cavity?

vagus nerves

In flaccid paralysis, muscles atrophy because they are not receiving neural stimulation. Damage to which specific part of the spinal cord would cause flaccid paralysis?

ventral root

Which cranial nerve transmits impulses for the senses of hearing and balance?

vestibulocochlear

An action potential releases neurotransmitter from a neuron by opening which of the following channels?

voltage-gated Ca2+ channels

Which ion causes neurotransmitter vesicles to fuse with the axon's membrane during the conduction of a nerve impulse from one neuron to the next?

Calcium

What best describes bipolar neurons?

Bipolar neurons are found in special sense organs, such as the eye and nose.

Bundles of nerve fibers (neuron processes) running through the CNS are called ________, whereas in the PNS they are called ________

Tracts and Nerves

What pair of cranial nerves extends to the thoracic and abdominal cavities?

Vagus

Rick quickly pulled his hand away from the hot stove. This reflex is best known as a(n) ________.

Withdrawal reflex

The mechanism by which the neurotransmitter is returned to a presynaptic neuron's axon terminal is specific for each neurotransmitter. Which of the following neurotransmitters is broken down by an enzyme before being returned?

acetylcholine