Nervous system- anatomy test
Which of the following is not one of the brain's four major regions?
Ventral ramus
Rick quickly pulled his hand away from the hot stove. What type of reflex is this?
Withdrawal reflex
Which of the following terms indicates a nerve impulse has been initiated and is being transmitted?
action potential
another word for sensory neuron
afferent neuron
astrocytes
are specialized glial cells that outnumber neurons by over fivefold. They contiguously tile the entire central nervous system (CNS) and exert many essential complex functions in the healthy CNS.
Which of the following conditions would result from damage to the cerebellum?
ataxia. Damage to the cerebellum interferes with balance and the coordination of skeletal muscle movements.
CNS includes...
brain and spinal cord, integrating and command centers
The midbrain, pons, and medulla oblongata are housed in the
brain stem
What produces cerebrospinal fluid (CSF)?
choroid plexus
another word for motor neuron
efferent neuron
Bacterial meningitis can spread into the brain, causing an inflammation of the brain known as
encephalitis
Which ciliated neuroglial cell circulates cerebrospinal fluid?
ependymal cells
Control of temperature, endocrine activity, metabolism, and thirst are functions associated with the ________.
hypothalamus
The hypothalamus is the "emotional-visceral" center of the brain and, thus, is an important part of the
limbic system (part of brain involved with behavioral and emotional responses)
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
Support cells in the central nervous system are collectively called
neuroglia
A molecule that carries information across a synaptic cleft is a
neurotransmitter
Immediately after an action potential is propagated, which one of the following ions rapidly diffuses out of the cell into the tissue fluid?
potassium ions
What part of the brain do we use when initiating skeletal muscle movement?
primary motor area
Each spinal nerve divides into a dorsal and a ventral ________.
ramus
Which of the following is the correct sequence in a typical reflex arc? (other words than before but same process)
receptor, sensory neuron, integration center, motor neuron, effector
After repolarization, what ions are pumped out of the cell?
Sodium
An action potential is caused by an influx of ________ ions into the cell.
sodium
What ion depolarizes the membrane when it diffuses into the axon of a neuron?
sodium
Amal died at the age of 71. If Amal had Alzheimer's disease, what would an autopsy of his brain reveal? in other words, what changes would occur in his brain
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.
dorsal ramus..
feeding the dorsal trunk (skin and muscles of the back)
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
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
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 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
How are neurons with several processes branching off the cell body, such as motor neurons and interneurons (association neurons), structurally classified?
multipolar
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
Hyperpolarization results from
slow closing of voltage-gated K+ channels
Anesthetics block nerve impulses by interfering with membrane permeability to ions, thus preventing an action potential from being generated. Which ion is being blocked?
sodium
correct sequence of events that correlates to the sequence of events of a nerve impulse..
sodium channels open and sodium ions diffuse inward the membrane becomes depolarized potassium channels open and potassium ions diffuse outward the membrane becomes repolarized
A polarized neuron is characterized by the presence of more ________ ions along the plasma membrane outside the cell and less ________ ions along the plasma membrane inside the cell.
sodium; potassium
Which branch of the autonomic nervous system (ANS) mobilizes the body during extreme situations, such as rage or fear?
sympathetic division "fight or flight"
What portion of the diencephalon acts as a relay station for sensory impulses traveling upward to the sensory cortex?
thalamus
Which of these parts of the brain is correctly matched with its region?
thalamus; diencephalon
The repolarization phase of an action potential results from
the opening of voltage-gated K+ channels
The depolarization phase of an action potential results from the opening of which channels?
voltage-gated Na+ channels Submit
Why is white matter "white"?
It contains a high concentration of myelin.
What is the first event of an action potential?
Sodium gates open and the membrane depolarizes.
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
Where in the neuron is an action potential initially generated?
axon hillock
Fibers that carry information from the skin, joints, and skeletal muscles to the central nervous system are
both somatic and sensory
During depolarization, which gradient(s) move(s) Na+ into the cell?
both the electrical and chemical gradients. a positive ion is driven into the cell because the inside of the cell is negative compared to the outside of the cell, and Na+ is driven into the cell because the concentration of Na+ is greater outside the cell.
CNS (central nervous system)
brain and spinal cord
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
Ganglia are collections of ________.
cell bodies
Saltatory conduction is a faster type of nerve impulse transmission that occurs along myelinated axons. Why is nerve impulse transmission faster in myelinated neurons?
The nerve impulse can jump from one node of Ranvier to the next, speeding the rate of nerve impulse transmission.
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?
cerebrovascular accident (CVA), or stroke
Cerebrospinal fluid is formed from blood by clusters of capillaries in the brain known as ________.
choroid plexuses
The dorsal and ventral rami split into dorsal and ventral ramus. The rami
contain nerves that provide visceral motor, somatic motor, and sensory information, with
Cerebrospinal fluid (CSF) does not flow through the
corpus callosum
PNS includes...
cranial and spinal nerves, communication lines within the body
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 __________. aka a potentially disabling disease of the brain and spinal cord (central nervous system).
multiple sclerosis.
What division of the autonomic nervous system is often called the "rest-and-digest" division?
parasympathetic
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
Neurons either conduct action potentials along the length of their axons, or they remain at rest. This statement best describes ________.
the all-or-nothing response
cerebrospinal fluid flows from
the lateral ventricles, to the third ventricle, and then to the fourth ventricle before leaving the brain and entering the central canal of the spinal cord or into the subarachnoid space.
When calcium ions enter the synaptic terminal...
they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.
ventral ramus
ventral ramus feeding the ventral trunk and limbs through the ventrolateral surface.
What is the value for the resting membrane potential for most neurons?
-70 mV. the resting membrane potential for neurons depends on the distribution of both Na+ and K+ across the cell membrane
brain 4 major regions
1. brain stem 2. cerebrum (cerebral hemispheres) 3. Diencephalon 4. Cerebellum
What is the magnitude (amplitude) of an action potential?
100mV. the membrane goes from -70 mV to +30 mV. Thus, during the action potential, the inside of the cell becomes more positive than the outside of the cell.
How many pairs of spinal nerves emerge from the spinal cord?
31
Which disease is a progressive, degenerative disease of the brain that ultimately results in dementia and is associated with a shortage of acetylcholine?
Alzheimer's disease
How is an action potential propagated along an axon?
An influx of sodium ions from the current action potential depolarizes the adjacent area.
Which of these neuroglial cells contributes to the structure of the blood-brain barrier?
Astrocytes
What part of the neuron releases vesicles containing neurotransmitters?
Axon terminals
Sally has a brain injury; she knows what she wants to say but can't vocalize the words. The part of her brain that deals with the ability to say words properly is and dealing with the regulation of breathing is known as
Broca's area
The concentrations of which two ions are highest outside the cell.
Na+ and Cl-. both Na+ and Cl- are in higher concentrations outside the cell.
The Na+-K+ pump actively transports both sodium and potassium ions across the membrane to compensate for their constant leakage. In which direction is each ion pumped?
Na+ is pumped out of the cell and K+ is pumped into the cell.
Which meningeal layer is filled with cerebrospinal fluid (CSF)?
Subarachnoid space
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. sodium channels are inactivated in the area that just had the action potential.
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.
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)
The largest nerve in the body, the sciatic nerve, belongs to the ________ nerve plexus.
sacral
What are the two main functional subdivisions of the nervous system?
sensory and motor
The gap between two communicating neurons is termed ________.
synaptic cleft
The small space between the sending neuron and the receiving neuron is the
synaptic cleft
Which of the following indicates a contusion? ( a bruise)
Coma due to injury to the reticular activating system
What specific part of the midbrain houses reflex centers for vision and hearing?
Corpora quadrigemina
What statement best describes the resting state of a neuron?
Neurons are polarized with more sodium ions outside the cell and more potassium ions inside the cell.
What is the most abundant glial cell in the central nervous system (CNS)?
astrocytes
he membranes of neurons at rest are very permeable to _____ but only slightly permeable to _____.
K+; Na+. more K+ moves out of the cell than Na+ moves into the cell, helping to establish a negative resting membrane potential.
What cells form the myelin sheaths around nerve fibers in the PNS?
Schwann cells
The velocity of the action potential is fastest in which of the following axons?
a small myelinated axon. the myelination acts as insulation and the action potential is generated only at the nodes of Ranvier. Propagation along myelinated axons is known as saltatory conduction.
What part of a neuron receives signals and sends a message to the cell body?
dendrite
Lidocaine is used as a local anesthetic to block the sensation of pain. It operates by preventing sodium channels from opening in affected neurons. The specific event lidocaine prevents is ________.
depolarization
The thalamus, hypothalamus, and epithalamus collectively constitute the ________.
diencephalon (interbrain)
What are the two major functional properties of neurons?
irritability and conductivity
The diencephalon (interbrain)
is a region at the core of the brain and is surrounded by the cerebral hemispheres. It is the connection between the brain stem and the cerebrum
Which of these is a deep pressure receptor?
lamellar corpuscle. They are nerve endings in the skin responsible for sensitivity to vibration and pressure.
