Test #4 review Flashcards
ventral horn
site of efferent soma
dorsal horn
site of axons and afferent neurons
lateral horn
horn containing autonomic neurons
ventral horn
multipolar neurons are common here.
The stage when vital signs (blood pressure, heart rate, and body temperature) reach their lowest normal levels.
NREM stage 4
Indicated by movement of the eyes under the lids; dreaming occurs.
REM
Theta and delta waves begin to appear
NREM stage 3
very easy to awaken; EEG shows alpha waves; may even deny being asleep.
NREM stage 1
typified by sleep spindles
NREM stage 2
begins about 90 minutes after the onset of sleep
REM
necessary for emotional health; may be neural “debugging”
REM
Gateway to the cerebrum
Thalamus
gateway to the cerebrum
thalamus
motor command center
cerebellum
survival center
brain stem
executive suite
cerebrum
visceral command center
hypothalamus
formed by the union of a cranial and a spinal root
accessory nerve
receptors located in epithelium of the nasal cavity
olfactory nerve
serves the senses of hearing and equilibrium
vestibulocochlear
helps to regulate blood pressure and digestion
vagus
turns the eyeball laterally
abducens
innervates the superior oblique muscle
trochlear
longest cranial nerve
vagus
damage to this nerve would cause dizziness, nausea and loss of balance
vestibulocochlear
involved in movement of the digestive tract
vagus
damage to this nerve would cause difficulty in speech and swallowing, but no effect on visceral organs
hypoglossal
damage to this nerve would keep the eye from rotating inferolaterally
trochlear
the division of the autonomic nervous system that oversees digestion, elimination, and glandular function; the resting and digesting subdivision
parasympathetic division
the division of the autonomic nervous system that prepares the body for activity or to cope with some stressor (danger, excitement, ); the fight, fright, and fligth subdivision.
sympathetic division.
short preganglionic, long postganglionic fibers
sympathetic
collateral ganglia
sympathetic
active after you have eaten a meal
parasympathetic
decreases heart rate
parasympathetic
maintenance functions
parasympathetic
stimulates ciliary muscles of the eye
parasympathetic
increases blood pressure
sympathetic
What are the functions of astrocytes?
- control the chemical environment around neurons.
- guide the migration of young neurons, synapase formation, and helping to determine capillary permability
- anchors neurons to blood vessles
- support and brace neurons.
ANS
motor fibers that conduct nerve impulses from the CNS to smooth muscles, cardiac muscle, and glands.
What are the ciliated CNS neuroglia that play an active role in moving cerebrospinal fluid called?
ependymal cells.
What does the central nervous system use to determine the strength of a stimulus?
frequency of action potentials.
Where are bipolar neurons commonly found?
In the retina of the eye,
Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials?
voltage-gated channel
An impulse from one nerve cell is communicated to another nerve cell via the
synapse
What is the role of acetylcholinesterase?
destroy ACh a brief period after its release by the axon endings.
What is the function of the autonomic nervous system?
innervation of glands
innervation of smooth muscle of the digestive tract
innervation of cardiac muscle.
immediately after an action potential has peaked, which cellular gates open?
potassium
Nerve cell adhesion molecules (N-CAMs)
are crucial for the development of neural connections.
An inhibitory postsynaptic potential is associated with
hyperpolarization.
Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane?
a single type of channel will open, permitting simultaneous flow of sodium and potassium.
When a sensory neuron is excited by some form of energy, the resulting graded potential is called a
generator potential.
Which brain nucleus is the body’s “biological clock”?
suprachiastmatic nucleus.
nuclei of cranial nerves, V, VI and VII are found in the
pons.
The arbor vitae refers to
cerebellar white matter.
the brain stem consists of the
midbrain, medulla and pons.
Which fissure separates the cerebral hemispheres?
longitudinal fissure
The primary auditory cortex is located in the
temporal lobe.
Why does a hyperpolarization phase generally follow a repolarization phase in an action potential?
In hyperpolarization some K channels remain open and NA channels reset. The period of increased K permeability typically lasts longer than needed to restore the resting state. As a result of the excessive K efflux before the K channels close, a hyperpolarization is seen on the AP curve as a slight dip following a spike.
What term best describes the cerebrum?
executive suite
A shallow grove on the surface of the cortex is called a
sulcus.
Generalizations of the cerebral cortex
- the hemispheres are NOT exactly equal in function
- each hemisphere is chiefly concerned with sensory and motor functions of the contralateral side of the body
- No functional area of the cortex works alone
- There cerebral cortex contains three kinds of functional areas.
If the causal portion of the Neural tube failed to develop properly the
spinal cord may be affected.
The blood-brain barrier is effective against
metabolic waste such as urea.
All of the following structures are of the limbic system
cingulate gyrus
amygdaloid nucleus
hippocampus
but caudate nucleus is not.
The process of linking new facts with old facts already stored in the memory bank is called
association.
What category of memory is involved when playing the piano?
procedural
The brain area that regulates activities that control the state of wakefulness or alertness of the cerebral cortex is the
reticular formation.
What does normal cerebrospinal fluid contain?
potassium, protein, glucose but NOT red blood cells
White matter is found in
the outer portion of the spinal cord, the corpus callosum, and the corticospinal tracts but not in the cerebral cortex.
The neuron cannot respond to a second stimulus
absolute refractory period
the interior of the cell becomes less negative due to an influx of sodium ions.
depolarization
the specific period during which potassium ions diffuse out of the neuron due to a change in membrane permeability.
repolarization
also called a nerve impulse transmitted by axons.
action potential
an exceptionally strong stimulus can trigger a response
relative refractory period.
cell bodies of sensory neurons may be located in ganglia lying
outside the central nervouse system.
Myelination of the nerve fibers in the CNS is
the job of the oligodendrocyte
during depolarization the inside the neuron’s membrane becomes
more positive.
in the myelinated axons the voltage-regulated sodium channels are concentrated at
the nodes of ranvier
large-diameter nerve fibers conduct impulses much faster than
small-diameter fibers.
The action potential is caused by permeability changes
in the plasma membrane.
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
If a post synaptic neuron is stimulated to threshold by spatial summation this implies
that the postsynaptic cells has many synapses with many presynaptic neurons.
immediately after an action potential has peaked which cellular gates open?
potassium
an inhibitory postsynaptic potential is associated with
hyperpolarization.
second-order neurons of both the specific and nonspecific ascending pathways terminate in the
thalamus
Loss of ability to perform skilled motor activities such as piano playing, with no paralysis or weakness in specific muscles, might suggest damage to the
premotor cortex.
Which brain waves are not normal for awake adults but are common for children?
theta
pressure, pain and temperature receptors in the skin are
exteroceptors
potentially damaging stimuli that result in pain are selectively detected by
nociceptors
which receptors adapt most slowly?
nociceptors
nerves that carry impulses toward the CNS only are
afferent nerves.
Which of the following is the correct simple spinal reflex arc?
receptor, afferent neuron, integration center, efferent neuron, effector
The secretions of the adrenal medulla act to supplement the effects of
sympathetic stimulation
Describe the ANS.
a system of motor neurons that innervates smooth and cardiac muscles and glands
-general visceral motor system
-involuntary nervous system
It is NOT a system of motor neurons that innervates all muscle cells.
Preparing the body for the “flight-or-fight” response is the role of the
sympathetic nervous system.
The somatic and autonomic nervous systems differ in all of the following except
all of the neurotransmitters.
the somatic and autonomic nervous system differ
to some degree in target responses to their neurotransmitters, their efferent pathways and their effectors.
Where do you find a cholinergeric nicotinic receptor?
-skeletal muscle motor end plates
- all postganglionic neurons
- adrenal medulla hormone producing cells
but you do not find them in parasympathetic target organs.
Control of temperature, endocrine activity and thirst are functions associated with the
hypothalmus.
Which of these effectors is not directly controlled by the autonomic nervous system?
skeletal muscle. BUT most glands, cardiac muscle and smooth muscle are controlled by the ANS.
Which of the following is not a result of the parasympathetic stimulation?
dilation of the pupils.
Examples of parasympathetic stimulation.
increased peristalsis of the digestive viscera
elimination of urine
salivation
Sympathetic division has short preganglionic and long post ganglionic fibers;
parasympathetic has long preganglionic and short postganglionic fibers.
Sympathetic origin is th thoracolumbar
parasympathetic origin is craniosacral
sympathetic ganglia are within a few centimeters of the CNS
parasympathetic are close to visceral organs served.
sympathetic has extensive branching of preganglionic fibers
parasympathetic has minimal branchin of pregagnlionic fibers.
sympathetic responses generally are widespread because
NE and epinephrine are secreted into the blood as part of the sympathetic response.
Sympathetic division stimulation cause
increased blood glucose, decrease GI peristalsis and increased heart rate and blood pressure.
The smooth muscle of the digestive viscera is served largely by the
tenth cranial nerve.
The route of major parasympathetic outflow from the head is via the
vagus nerve.
para sympathetic functions include
lens accommodation for close vision.
Emotions influence autonomic reactions primarily through integration in the
hypothalamus.
What seven areas of the body does the hypothalamus control?
- control the ANS, regulates the ANS activitity by controling the activity centers in the brain stem and spinal cord.
- initiate physical responses to emotions. for example, a fearful person has a pounding heart, high blood pressure, pallor, sweating and a dry mouth.
- regulate food intake: in response to changing bllod levels of certain nutrients (glucose and amino acids) or hormones, the hypothalamus regulates feelings of hunger and satiety.
- regulate water balance and thirst
- regulate sleep-wake cycle: suprachiasmatic nucleus sets the timing of the sleep cycle.
- control endocrine system function: it’s releasing and inhibiting hormones control the secretion of hormones by the anterior pituitary gland.
Names an exteroceptor that is not a cutaneous receptor and explain why it is called an exteroceptor.
Exteroceptors that are not cutaneous receptors include the chemoreceptors of the tongue and nasal mucosa, the photoreceptors of the eyes, and the mechanoreceptors of the inner ear. These all monitor changes in the external environment, so they are classified as exteroceptors.
How is hypertension (high blood pressure) related to the ANS?
Hypertension may result fro an overactive sympathetic vasoconstrictor response promoted by continuous high levels of stress. Hypertension is sometimes treated with andrenergic receptor-blocking drugs that counteract the effects of the sympathetic nervous system on the cardiovascular system.
Compare the somatic system and autonomic system, structurally and functionally.
The somatic nervous system stimulates skeletal muscles whereas the ANS innervates cardiac and smooth muscle and glands. they differ in their effectors, efferent pathways and Target organ responses.
In the somatic nervous system, the motor neuron cell bodies are in the CNS, and their axons extend in spinal or cranial nerves all the way to the skeletal muscles they activate. Somatic motor fibers are typically thick, heavily myelinated Group A fibers that conduct nerve impulses rapidly.
In contrast, the ANS uses a two-nueron chain to reach it’s effectors:
1. The cell body of the first neuron, the preganglionic neuron, resides in the brain or spinal cord. Its axon, the preganglionic axon, synapses with the second motor neuron.
2. The postganglionic neuron (sometimes called the ganglionic neuron) is the second motor neuron. Its cell body is in an autonomic ganglion outside the CNS. Its axon, the postganglionic axon extends to the effector organ.
Because the preganglionic axons are thin, lightly myelinated fibers, and the postganglionic axons are even thinner and nonmyelinated, conduction through the ANS is slower that conduction in the somatic nervous system
-Somatic motor division lacks lacks ganglia entirely.
-All somatic motor neurons release one neurotransmitter, ACh while Autonomic postganglionic fibers release two neurotransmitters, NE which is secreted by most sympathetic fibers and ACh secreted by parasympathetic fibers.
Most of the body;s adaptations to changing internal and external conditions involve both skeletal muscles and visceral organs.
