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95 terms

Unit 6

Bio -120
STUDY
PLAY
Choose the false statement about nerves.
The majority of a nerve's bulk is due to axons.
CNS nerve fibers lack the intrinsic capacity to regenerate, while PNS nerve fibers are able to regenerate. ( true or false)
true
The majority of the cranial nerves attach to the:
brain stem
A joint and the muscle that moves that joint tend to be innervated by different nerves ( true or false)
false
Complex receptors are also called sense organs
( true or false)
true
______ are collections of neuron cell bodies associated with nerves in the PNS.
Ganglia
Which structure is involved in the segmental level of motor control?
Spinal cord
In carpal tunnel syndrome the ______ is compressed
median nerve
The peripheral nervous system (PNS) includes the brain and spinal cord ( true or false)
false
Which of the following does not occur as people age
Peripheral nerves die off.
The knee-jerk reflex is an example of a:
stretch reflex
_______ do not exhibit the property of adaptation
Tonic receptors
The phrenic nerve serves the:
diaphragm
The thickest and longest nerve in the body is the
sciatic nerve
_________ are receptors that can respond to changes in pressure.
Mechanoreceptors
Spinal nerves are all classified as:
mixed nerves.
Which of the following is not used to classify sensory receptors?
The number of dendritic endings present
The first level of neural integration in the somatosensory system is the ______ level.
receptor
Somatic reflexes activate:
skeletal muscle.
There are ____ pairs of cranial nerves.
12
Trauma to a nerve of this plexus may cause wrist drop
Brachial plexus
The phrenic nerve branches from this plexus.
Cervical plexus
A fall or improper administration of an injection to the buttocks may injure a nerve of this plexus
Sacral plexus
The obturator and femoral nerves branch from this plexus.
Lumbar plexus
Striking the "funny bone" (ulnar nerve) may cause injury to a nerve of this plexus
Brachial plexus
Serves the senses of hearing and equilibrium
Vestibulocochlear
Turns the eyeball laterally.
Abducens
Helps to regulate blood pressure and digestion
Vagus
Receptors located in epithelium of the nasal cavity
Olfactory
Formed by the union of a cranial and a spinal root.
Accessory
Prevents muscle overstretching and maintains muscle tone.
Stretch
Consists of an ipsilateral withdrawal reflex
and a contralateral extensor reflex; important
in maintaining balance
Crossed-extensor
Tests both upper and lower motor pathways. The sole of the foot is stimulated with a dull instrument
Plantar
Produces muscle relaxation and lengthening in response to tension; the contracting muscle
relaxes as its antagonist is activated.
Golgi tendon
Produces a rapid withdrawal of the body part from a painful stimulus; ipsilateral
Flexor
Potentially damaging stimuli that result in pain are selectively detected by ________
nociceptors
The ________ nerve is not a branch of the trigeminal nerve.
cervical
Which of the following nerves does not arise from the brachial plexus?
phrenic
The abducens nerve ________.
supplies innervation to the lateral rectus muscle of the eye
Which of the following is the correct simple spinal reflex arc?
receptor, afferent neuron, integration center, efferent neuron, effector
Which receptors adapt most slowly?
nociceptors
Problems in balance may follow trauma to which nerve?
vestibulocochlear
Select the statement that is most correct.
Ganglia associated with afferent nerve fibers contain cell bodies of sensory neurons.
In a crossed-extensor reflex, if the right arm was grabbed it would flex and the left arm would ________.
extend
Spinal nerves exiting the cord from the level of L4 to S4 form the ________
sacral plexus
A patient who received a blow to the side of the skull exhibits the following signs and symptoms on that side of the face: he is unable to close his eye, and the corner of his mouth droops. Which cranial nerve has been damaged?
facial
The patellar "knee jerk" reflex is an example of a(n) ________
stretch reflex
Irritation of a major nerve of this plexus may cause hiccups.
cervical plexus
A major nerve of the lumbar plexus is the ________.
femoral
Striking the "funny bone" is actually stimulation of (or injury to) the ________.
ulnar nerve
A fall or an improperly delivered gluteal injection could result in ________.
sciatica
If the ventral root of a spinal nerve were cut, what would be the result in the tissue or region that nerve supplies?
a complete loss of voluntary movement
A fracture of the ethmoid bone could result in damage to which cranial nerve?
olfactory
Which of the following is not a main level of neural integration in the somatosensory system?
segmental
A reflex that causes muscle relaxation and lengthening in response to muscle tension is called a ________.
Golgi tendon reflex
After axonal injury, regeneration in peripheral nerves is guided by ________.
Schwann cells
Nerves that carry impulses toward the CNS only are ________
afferent nerves
Oculomotor nerves are responsible for which of the following functions
Focusing the eyes on close objects
Which of the following target organs/systems is affected by the sympathetic nervous system, but not affected by the parasympathetic nervous system?
Cellular metabolism
Conduction through the autonomic efferent chain is faster than conduction in the somatic motor system. (true or false)
false
Which of the following is responsible for the overall integration of the autonomic nervous system?
Hypothalamus
Which of the following is a way in which the somatic and autonomic nervous systems are similar?
Both systems have motor fibers.
Which of the following does not receive branch fibers of the vagus nerves?
Inferior hypogastric plexus
Which types of drugs are used to help relieve depression?
Drugs that prolong the activity of norepinephrine on the postsynaptic membrane help to relieve depression.
Which of the following best demonstrates an example of cooperation of the parasympathetic and sympathetic nervous systems?
Parasympathetic stimulation causes vasodilation of blood vessels in the penis, leading to erection; sympathetic stimulation then causes ejaculation.
The two types of receptors that bind acetylcholine are _______ and _______ receptors.
Nicotinic; muscarinic
Why might an individual experience the phenomenon known as "referred pain"?
Visceral pain afferents travel along the same pathways as somatic pain fibers.
The sympathetic nervous system is often referred to as the "resting and digesting" system. (true or false)
false
For which of the following activities is the parasympathetic nervous system generally responsible?
Resting and digesting
Which of the following does not describe the ANS?
a system of motor neurons that innervates all muscle cells
Cardiovascular effects of the sympathetic division include all except ________.
dilation of the blood vessels serving the skin and digestive viscera
Control of temperature, endocrine activity, and thirst are functions associated with the ________.
hypothalamus
The white rami communicantes ________.
carry preganglionic axons to the sympathetic chain
A drug that might be used specifically to reduce heart rate in cardiac patients could be ________.
a beta-blocker
Beta-blockers ________.
decrease heart rate and blood pressure
The secretions of the adrenal medulla act to supplement the effects of ________.
sympathetic stimulation
Over 90% of all parasympathetic fibers are derived from cranial nerve number ________.
X
Sympathetic responses generally are widespread because ________.
NE and epinephrine are secreted into the blood as part of the sympathetic response
Visceral reflex arcs differ from somatic in that ________.
visceral arcs involve two motor neurons
Preparing the body for the "fight-or-flight" response is the role of the ________.
sympathetic nervous system
Fibers that enter and leave the sympathetic chain without synapsing form structures called ________.
splanchnic nerves
The route of major parasympathetic outflow from the head is via the ________.
vagus nerve
Which is a uniquely sympathetic function?
regulation of body temperature
Autonomic dysreflexia ________.
involves uncontrolled activation of autonomic neurons
The "resting and digesting" division of the autonomic nervous system is the ________.
parasympathetic division
Erection of the penis or clitoris ________.
is primarily under parasympathetic control
Emotions influence autonomic reactions primarily through integration in the ________.
hypothalamus
Autonomic ganglia contain ________.
the cell bodies of motor neurons
Which of these effectors is not directly controlled by the autonomic nervous system?
skeletal muscle
The possibility of some control over autonomic responses is demonstrated by ________.
biofeedback
Sympathetic nerves may leave the spinal cord at which vertebra?
first thoracic
Which of the following is not a plexus of the vagus nerve?
celiac
Which of the following is not a result of parasympathetic stimulation?
dilation of the pupils
Sympathetic division stimulation causes ________.
increased blood glucose, decreased GI peristalsis, and increased heart rate and blood pressure
Raynaud's disease ________.
is characterized by exaggerated vasoconstriction in the extremities