Chapter 7: Nervous System
The membrane potential is becoming more positive than the resting membrane potential.
Depolarize
Which of the following terms indicates a nerve impulse has been initiated and is being transmitted?
action potential
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 most abundant glial cell in the central nervous system (CNS)?
astrocytes
The root word ___ means "self."
auto-
The ______ nervous system is the part of the brain under involuntary, or automatic, control.
automatic
What part of the neuron releases neurotransmitters from vesicles?
axon terminals
What part of a neuron receives signals and sends a message to the cell body?
dendrite
An infection of the meninges is called
meningitis
How are the fibers found in the ventral roots of spinal nerves classified?
motor fibers
Karen, who is in her mid-forties, has been slurring words and has partial loss of vision in her left eye. She is also having coordination problems. Her doctor thinks she has an autoimmune disease that is destroying the myelin sheaths surrounding nerve fibers. If the doctor's diagnosis is correct, the disease Karen has is __________.
multiple sclerosis
The root word _____ means "nerve."
neur-
_______ are supporting cells of the nervous system.
neuroglia
A molecule that carries information across a synaptic cleft is a
neurotransmitter.
Which cranial nerves control movement of the eyes?
oculomotor, trochlear, and abducens
Which of these neuroglial cells forms the myelin sheath in the central nervous system?
oligodendrocytes
Melanie has a type A personality. She is constantly pushing herself to be the best at everything she does. This behavior has led to several stress-induced conditions, including severe digestion problems, including ulcers. Which division of the nervous system listed below would be most related to Melanie's stress-induced digestive problems?
sympathetic; Stress, both physical and mental, stimulates the sympathetic nervous system.
The small space between the sending neuron and the receiving neuron is the
synaptic cleft.
Which of these parts of the brain is correctly matched with its region? primary motor area; brain stem pons; cerebellum thalamus; diencephalon corpora quadrigemina; medulla oblongata
thalamus; diencephalon
which of the following is an alternate name for the parasympathetic nervous system? thoracolumbar division the fight-or-flight system the exercise division the craniosacral division the emergency division
the craniosacral division
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
During an action potential, the rapid decrease in sodium permeability and simultaneous increase in potassium permeability is responsible for __________. returning to the resting membrane potential after the action potential the depolarization phase the hyperpolarization phase the repolarization phase
the repolarization phase; The repolarization phase of the action potential occurs just after the action potential peak, as the membrane potential becomes more negative again.
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
Bundles of nerve fibers (neuron processes) running through the CNS are called ________, whereas in the PNS they are called ________.
tracts; nerves
What cranial nerve pair supplies many organs in the ventral body cavity? accessory nerves trigeminal nerves vagus nerves glossopharyngeal nerves
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
The root word_____ means "inflammation" or "disease."
-itis
Which of these is a sympathetic effect? Blood vessels constrict. Heart rate slows. Bronchioles within the lungs constrict. Increased saliva production.
Blood vessels constrict.
CNS (central nervous system)
Brain and spinal cord Integration and command center
The membrane potential is more negative than the resting membrane potential.
Hyperpolarize
Why is white matter "white"?
It contains a high concentration of myelin.
threshold stimulus
Opening of voltage-gated Na+ channels, Na+ ion flow into the neuron increases, Depolarization of the membrane to +30 mV, K+ ion flow out of the neuron increases, Repolarization of the membrane
Which of the following is a disease of the basal nuclei? aphasia Parkinson's disease encephalitis multiple sclerosis
Parkinson's disease; Basal nuclei are involved in starting and stopping voluntary muscle movement.
The membrane potential is moving from a more positive value toward resting membrane potential.
Repolarize
What is the first event of an action potential?
Sodium gates open and the membrane depolarizes
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 carries motor signals to skeletal muscles. The spinal cord carries sensory information toward the central nervous system (CNS). The spinal cord initiates reflexes. The spinal cord sends sensory information to the brain and carries motor signals from the brain to motor neurons
The spinal cord sends sensory information to the brain and carries motor signals from the brain to motor neurons.
The root word ____ means "brain."
cerebr-
The conscious part of the brain is the _____
cerebrum
Which spinal plexus gives rise to the phrenic nerve, and what organ does this nerve supply?
cervical; diaphragm
What produces cerebrospinal fluid (CSF)?
choroid plexus
PNS (peripheral nervous system)
cranial nerves and spinal nerves, communication lines with the body
The thalamus, hypothalamus, and epithalamus collectively constitute the ________.
diencephalon interbrain
The root word ___ means "back."
dors-
the roots of the spinal cord on the posterior side are called _____ roots.
dorsal
During the action potential, when does sodium permeability initially DECREASE? during the peak of depolarization during repolarization during the rising phase of depolarization during hyperpolarization
during the peak of depolarization; At the peak of the action potential, the inactivation gates of the voltage-gated Na+ channels are rapidly closing. This causes a rapid decrease in the membrane's permeability to Na+.
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? perineurium, endoneurium, epineurium endoneurium, epineurium, perineurium epineurium, perineurium, endoneurium epineurium, endoneurium, perineurium perineurium, epineurium, endoneurium
epineurium, perineurium, endoneurium
Amal died at the age of 71. If Amal had Alzheimer's disease, what would an autopsy of his brain reveal?
he presence of beta-amyloid plaques, shrunken gyri, and an atrophied brain
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? stimulates secretion of epinephrine increases cellular metabolism increases peristalsis within the stomach and small intestines increases heart rate
increases peristalsis within the stomach and small intestines
What type of neuron connects sensory and motor neurons in neural pathways?
interneurons (association neurons)
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 part of the brain do we use when initiating skeletal muscle movement?
primary motor area
Which of these lists the components of a reflex arc in the correct sequence?
receptor; afferent neuron; control center; efferent neuron; effector
Which of the following neurons is classified as a unipolar neuron?
sensory neuron
Which division of the peripheral nervous system activates skeletal muscles?
somatic nervous system