Practice Exam (Exam 2) Flashcards
(24 cards)
In the peripheral nervous system, the cell bodies of primary sensory afferents are located
in the:
A. Autonomic ganglia
B. Dorsal horn of the spinal cord
C. Ventral horn of the spinal cord
D. Dorsal Root ganglia
E. Spinothalamic tract
D: D. Dorsal Root ganglia
- When acetylcholine binds to muscarinic receptors
A. Na+ ion channels open.
B. G proteins are activated.
C. K+ channels open.
D. Cl- channels open.
E. Ca2+ channels open
B. G proteins are activated.
Which one of the following characteristics for all muscle types (skeletal, cardiac, and
smooth) is TRUE?
a) Contain striations
b) Utilize GAP junctions to spread contractions
c) Require Ca2+ release from the SR to contract
d) Use recruitment to increase the force of contraction
e) Utilize troponin to regulate Ca2+
c) Require Ca2+ release from the SR to contract
During excitation-contraction coupling in Skeletal Muscle, which of the following
events takes place?
A. Ca2+ is released from the sarcoplasmic reticulum (SR) and the extracellular fluid (ECF)
and binds to calmodulin
B. Ca2+ is released from the SR and binds to tropomysin
C. Ca2+ binds to the sarcolemma and causes an end plate potential
D. Ca2+ is released from SR and binds to troponin
E. Ca2+ ATPase pumps Ca2+ back into the ECF
D. Ca2+ is released from SR and binds to troponin
. Which one of the following characteristics about fast-twitch glycolytic muscle fibers is
FALSE?
a) High myoglobin content
b) Large diameter
c) Low oxidative capacity
d) Fast myosin ATPase speed
e) Low mitochondrial density
a) High myoglobin content
Which of the following statements about smooth muscle fibers is TRUE?
A. Smooth muscle fibers are activated only by the somatic motor division
B. ATPase activity is faster than in skeletal muscle
C. When depolarized, Ca2+ is released from the SR and enters from the ECF and binds
troponin
D. Myosin light chain kinase dephosphorylates myosin light chains
E. When depolarized, Ca2+ is released from the SR and enters from the ECF and binds to
calmodulin
E. When depolarized, Ca2+ is released from the SR and enters from the ECF and binds to
calmodulin
- Blood that has entered the heart through the vena cava leaves the __________ when the
________opens.
A. Left ventricle, aortic valve
B. Right atrium, pulmonary valve
C. Left ventricle, mitral valve
D. Right ventricle, pulmonary valve
E. Left ventricle, tricuspid valve
D. Right ventricle, pulmonary valve
Which one of the following statements about cardiac contractile cells is FALSE?
A. The plateau phase is due to an increase in K+ permeability and a decrease in Ca2+
permeability
B. Contractile cells have long action potential generation that doesn’t allow for tetany
and fatigue
C. The opening of Na+ channels is responsible for the initiation of depolarization
D. The decline of membrane potential (repolarization) is due to opening of slow type K+
channels
E. Are affected only by the sympathetic branch of the autonomic nervous system
A. The plateau phase is due to an increase in K+ permeability and a decrease in Ca2+
permeability
. Mr. Brown has a blood pressure of 110/70 mmHg and cardiac output of 5 L/min. His
heart rate is 83 bpm. Calculate his total peripheral resistance.
A. 83.3 mmHg
B. 1860 L/min
C. 16.7 mmHgˑmin /L
D. 416.5 mmHg/L
E. .06 mmHgˑmin /L
C. 16.7 mmHgˑmin /L
- Increasing ___________ would increase the sacromere length (stretching) in contractile
cardiomyoctes leading to increased __________.
A. End diastolic volume, stroke volume
B. End systolic volume, stroke volume
C. End diastolic volume, heart rate
D. End systolic volume, afterload
E. Preload, afterload
A. End diastolic volume, stroke volume
- Resistance in the cardiovascular system
A. Never changes
B. In decreased by decreasing the diameter of the vessel
C. Is decreased by increasing the length of the vessel
D. Is independent of the diameter of the vessel
E. Is increased by increasing the viscosity of the fluid
E. Is increased by increasing the viscosity of the fluid
- Edema can be caused by
A. A decrease in arterial hydrostatic pressure
B. An increase in blood plasma protein concentration
C. An increase in interstitial protein concentration
D. A decrease in filtration at the arteriole
E. An increase in absorption in the venule
C. An increase in interstitial protein concentration
Name the following components of a reflex arc/pathway. (0.5 point each)
A- Sensory Receptor
B. Afferent Sensory Neuron
C. Interneuron (integration)
D. Efferent motor neuron
What neurotransmitters are released during a “fight or flight” scenario? (0.5 point)
sympathetic activation
Ach would bind to nicotinic Ach recptors on the preganglionic neuron
NE would bind to adrenergic receptors on the Effector site
Describe the mechanisms that occur when these neurotransmitters bind to Arteriole
smooth muscle? Be specific with the type of receptors that are involved and the effects
that are elicited (ie- effect on diameter). (2 points)
B. NE/E would bind to alpha 1 receptors, causing vasoconstriction (and increased
resistance), shunting blood away from GI tract and visera
NE/E would also bind to Beta 2 receptors causing vasodilation (reduced resistance)
increasing blood flow to heart and skeletal muscle.
Rigor mortis, a condition in which skeletal muscles temporarily remain in a rigid state
of partial contraction due to the absence of ATP, occurs a few hours after death.
Briefly explain the mechanism of why the loss of ATP would lead to muscle rigidity.
(ie- what is the role of ATP in muscle relaxation?) (1 point)
Rigor Mortis results because there is no longer ATP to fuel calcium
reuptake back into the SR (via the Ca2+ ATPase). Thus, calcium is in high
concentration in the cytoplasm and is allowed to stay bound to troponin.
Calcium binding to troponin allows tropomyosin to change configuration
on actin so that myosin binding sites are exposed. ALSO, ATP is needed to
release myosin from actin following the powerstroke.
Name the three ways that skeletal muscle can get ATP (0.5 points/each)
Creatine phosphate
Oxidative phosphorylation (aerobic metabolism)
Glycolysis (anaerobic metabolism)
Dr. Skinner likes to run marathons. What pathway answered above would you expect
to be most utilized during his race? (0.5 points)
Oxidative phosphorylation
Name the muscle fiber type that would be most actively recruited by Dr. Skinner (ie-
fast twitch glycolytic, etc.) (0.5 points
Fast twitch oxidative
Explain the physiological mechanism by which the parasympathetic nervous system
can alter the frequency of action potential generation. (please make reference to the
effect on the heart and the types on ion channels that are effected/ion flow) (1.5
points)
Parasympathetic innervation will reduce action potential generation. Ach
will bind to cholinergic muscarinic receptors on pacemaker cells
increasing K+ permeability, hyperpolarizing the cell. Ach will also delay
the opening of the T-type calcium channels, reducing the ability to reach
threshold.
Define the correct order of the electrical conduction pathway that these action
potentials will travel through the heart. (1 point)
SA Node
Internodal pathways
AV node
Bundle of His
Bundle Branches
Purkinjie Fibers
Define Edema? (0.5 points)
The buildup of fluid in the interstitial space
Based on your answer in part ii, would this person have Edema (0.5 points)?
Yes, the increase in hydrostatic pressure would cause the buildup of fluid in
the interstitial space. Filtration would be higher then absorption.
Would increasing capillary hydrostatic pressure encourage fluid movement in or out
of the capillary? (1 point)
Out of the capillary
