CHAPTER 2: NEUROPHYSIOLOGY | BRS PHYSIOLOGY EXAM
QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS
VERIFIED
What is a feature of the
sympathetic, but not the parasympathetic, nervous
system?
1. Preganglionic neurons originate in the
thoracolumbar spinal cord.
2. Postganglionic neurons that release
norepinephrine.
*further characterized by short preganglionic neurons that synapse in ganglia located
in the paravertebral chain (not in the effector organs)
Which autonomic receptor mediates an increase
in heart rate?
Heart rate is increased by the stimulatory effect of norepinephrine on B1 receptors in
the sinoatrial (SA) node. There are also sympathetic B1 receptors in the
heart that regulate contractility.
Which reflex is responsible for monosynaptic
excitation of ipsilateral homonymous muscle?
, The stretch reflex is the monosynaptic response to stretching of a muscle. The reflex
produces contraction and then shortening of the muscle that was originally
stretched (homonymous muscle).
Which type of cell in the visual cortex responds
best to a moving bar of light?
Complex cells respond to moving bars or edges with the correct orientation. Simple
cells respond to stationary bars, and hypercomplex cells respond to lines,
curves, and angles. Bipolar and ganglion cells are found in the retina, not in the visual
cortex.
Administration of what drug is contraindicated in a 10-year-old child with a
history of asthma?
Asthma, a disease involving increased resistance of
the upper airways, is treated by administering drugs that produce bronchiolar dilation
(i.e., B2 agonists). B2 Agonists include isoproterenol, albuterol, epinephrine, and, to a
lesser extent, norepinephrine.
B2 Antagonists, such as propranolol, are strictly contraindicated because they cause
constriction of the bronchioles.
The excessive muscle tone produced in decerebrate
rigidity can be reversed by . . .
Decerebrate rigidity is caused by increased reflex muscle
spindle activity. Stimulation of group Ia afferents would enhance, not diminish, this reflex
activity.
QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS
VERIFIED
What is a feature of the
sympathetic, but not the parasympathetic, nervous
system?
1. Preganglionic neurons originate in the
thoracolumbar spinal cord.
2. Postganglionic neurons that release
norepinephrine.
*further characterized by short preganglionic neurons that synapse in ganglia located
in the paravertebral chain (not in the effector organs)
Which autonomic receptor mediates an increase
in heart rate?
Heart rate is increased by the stimulatory effect of norepinephrine on B1 receptors in
the sinoatrial (SA) node. There are also sympathetic B1 receptors in the
heart that regulate contractility.
Which reflex is responsible for monosynaptic
excitation of ipsilateral homonymous muscle?
, The stretch reflex is the monosynaptic response to stretching of a muscle. The reflex
produces contraction and then shortening of the muscle that was originally
stretched (homonymous muscle).
Which type of cell in the visual cortex responds
best to a moving bar of light?
Complex cells respond to moving bars or edges with the correct orientation. Simple
cells respond to stationary bars, and hypercomplex cells respond to lines,
curves, and angles. Bipolar and ganglion cells are found in the retina, not in the visual
cortex.
Administration of what drug is contraindicated in a 10-year-old child with a
history of asthma?
Asthma, a disease involving increased resistance of
the upper airways, is treated by administering drugs that produce bronchiolar dilation
(i.e., B2 agonists). B2 Agonists include isoproterenol, albuterol, epinephrine, and, to a
lesser extent, norepinephrine.
B2 Antagonists, such as propranolol, are strictly contraindicated because they cause
constriction of the bronchioles.
The excessive muscle tone produced in decerebrate
rigidity can be reversed by . . .
Decerebrate rigidity is caused by increased reflex muscle
spindle activity. Stimulation of group Ia afferents would enhance, not diminish, this reflex
activity.
