Physiology Exam 1
3
The first heart sound corresponds to number
Force generation in cardiac muscle is modulated by Ca++ calmodulin interaction
The inotropic state of cardiac muscle can be altered because
An increase in the amount and rate of shortening following an increase in resting (diastolic) fiber length over a normal physiologic range.
The length-tension relationship in cardiac muscle allows the heart to make automatic adjustments in its output. This is accomplished by:
Nitric oxide
The main endothelial control mechanism is exerted by:
Decrease venous compliance
An instantaneous increase in venous-motor tone will:
The atria
As a pump, the chambers of the heart that receive blood from systemic and pulmonary circuits are:
response
Biosynthesis and release of insulin by pancreatic beta-islet cells is an example of which communication stage:
Cardiac Output
The amount of blood ejected by the heart each minute is:
High pedal venous pressures
A 23-year old pregnant woman in her 3rd Trimester complains to her friend that her feet and ankles are frequently swollen. The swelling is most likely caused by which of the following?
Phase 2 would be reduced
A 65-year old man with history of hypertension is prescribed a calcium channel blocker to help reduce his blood pressure. Based on the figure, what is the likely effect of this drug on the ventricular myocardium?
Grade I Hypertension
A blood pressure reading measuring Systolic over 140mmHg and diastolic over 90mmHg would be diagnosed as:
decreased conduction through the AV node
A female patients electrocardiogram ECG shows TWO "P" waves preceding each QRS complex the interpretation of this pattern is
Atrioventricular (AV) node
A person ECG has no P wave but has a normal QRS complex and a normal T wave. Therefore, his pacemaker is located in
hypertrophy
A total of more than 35mm in height of the S wave in V1 and R wave in V5 would indicate
Smaller endplate potentials
An 18-year-old college woman comes to the student health service complaining of progressive weakness. She reports that occasionally her eyelids "droop" and that she tires easily, even when completing ordinary daily tasks such as brushing her hair. She has fallen several times while climbing a flight of stairs. These symptoms improve with rest. The physician orders blood studies, which reveal elevated levels of antibodies to nicotinic receptors. Assuming the antibodies block the nicotinic receptors, what changes would you expect at the neuromuscular junction?
summation
An amplified sustained contraction produced by repeated stimulation of the muscle fiber is known as
the MAP will decrease and hydrostatic pressure in veins and arteries of the legs will increase
Before the regulatory reflexes respond, a person who stands up quickly from a supine position will show the following instantaneous change in cardiovascular dynamics:
Left Anterior Descending Artery
Blockage in this artery would result in diminished blood flow to the apex of the heart.
Increased velocity
Blood that is traversing a narrowed artery may develop turbulent flow and a Reynold's number higher than 2000. The main factor increasing the possibility of turbulent flow in this case is:
The frequency of miniature end plate potentials; The end plate potentials
Botulinum toxin is used to treat certain eye disorders such as crossed eyes (strabismus) and uncontrolled blinking (blepharospasm), to treat muscle stiffness/spasms or movement disorders (such as cervical dystonia also called spasmodic torticollis), and to reduce the cosmetic appearance of wrinkles. The injection of botulinum toxin into skeletal muscle reduces
junctions and fenestrations
Bulk Flow from the capillaries to the tissues occurs via:
Binding sites revelation
Calcium binds to troponin in order for this process to occur:
Ca++
Calcium influx into the sarcoplasm of cardiac muscle triggers the leak of what molecules into the sarcoplasm?
Regulated by beta adrenergic receptors that modulate cAMP phosphorylation with increased calcium release and increased contraction on next beat
Calcium released in the excitation contraction process of cardiac muscle fibers is:
Plateau Phase
Cardiac muscle fibers maintain a contraction for longer durations than skeletal muscles, this is due to
5 liters/minute
Cardiac output in an average adult at rest is
Ca2++
Conotoxins from cone snail venom often block currents in the presynaptic terminal to decrease neurotransmitter release without inhibiting action potentials. Which current is blocked by the w-conotoxins?
It increases CVP and MAP
Ephedrine is a drug that increases cardiac rhythm and contractility plus arteriolar and venous constriction. Which of the following best describes the effect of ephedrine in the cardiovascular system?
Alpha receptors
Epicardial coronary vessels have a preponderance of:
calcium
Excess of these intracellular ions can have an effect on heart muscle causing spastic contractions
elevation
In a routine examination of an EKG, which do we look at to help determine an infarction has occurred (STEMI)?
action of adenylyl cyclase
In cells, physiological amplification of cell signaling is most often achieved by:
Increase by 40-60%
In patients with hypertension, you can expect a mean arterial pressure to:
cardiac output will decrease
In severe mitral valve regurgitation, the valve allows blood to flow back to the left atrium during systole. Under this condition:
Type 1
In some aspects, Cardiac muscle is similar to which type of Skeletal muscle?
Na+ influx
In the action potential graph for cardiac muscle, Phase 0 corresponds to:
Orthostatic changes
In the morning, as you get up from bed, you arise quickly from supine to sitting then standing. You suddenly feel dizzy for a short period of time before that sensation goes away. The physiologic explanation for this occurrence is:
The nicotinic receptors at her neuromuscular junction were insufficiently stimulated
Nerve stimulation studies show decreased responsiveness of skeletal muscle on repeated stimulation of motoneurons. The woman is diagnosed with myasthenia gravis and is treated with the drug neostigmine which inhibits the acetylcholine esterases. After treatment, she reports a return of muscle strength. The findings in this case suggest that prior to treatment:
stroke volume
Frank Starlings curve depicts the relationship between preload and:
This specialized sensory structure that informs the CNS of the amount of force the muscle is generating is known as
Golgi Tendon Organs
chronic aortic stenosis
Hypertrophy of both left ventricle and left atrium is often seen in which of the following valvular disease?
Type 1
This type of muscle fiber has a slow speed of contraction
Autosomal dominant disorder; Degeneration of mitral valve; Connective tissue disorder; Calcification of valve due to aging (All of the above)
Identify the possible causative factors of valvular diseases:
D. 5.25 L/min
If the heart rate is 70 beats/min, EDV is 140 ml, and ESV 65 ml, then the cardiac output of this ventricle is closest to A. 8.00 L/min B.3.45 L/min C. 4.55 L/min D. 5.25 L/min
The driving force for Na+ is very large
If the nicotinic channels at the neuromuscular junction pass both Na+ and K+ why does stimulation of these channels cause depolarization of the skeletal muscle?
Q-T interval
If you suspect drug toxicity, you would see a prolonged:
Systolic blood pressure value read on sphygmomanometer
Korotkoff sound 1 corresponds to:
C. Systolic pressure
The changes in hemodynamics and in the structural characteristics of the heart and arterial system that take place during aging effect which part of blood flow most adversely? A. Cardiac Output B. Mean Arterial Pressure C. Systolic pressure D. Diastolic Pressure
2 cm
Mitral stenosis is considered when the diameter is less than ____ cm, and when hemodynamics changes become clinically apparent?
power stroke
Myosin heads swiveling causing displacement of the actin filament is known as:
D. arterial and arteriolar resistance
Of the physical factors that affect coronary blood flow, which one would be considered of greatest importance? A. xtravascular compression exerted by the heart muscle on the coronary vessels B. systolic pressure C. aortic pressure D. arterial and arteriolar resistance
QRS Complex
On an EKG, this represents the events corresponding to ventricular depolarization.
3 --> 5
On the graph showing left ventricular volume and pressure, isovolumetric contractions occurs between points
light chains
Which component of the Myosin molecule binds to the active sites on the actin filament?
systemic edema associated with right ventricular failure
Which of the following IS NOT a symptom associated with mitral valve regurgitation?
High pressure arterial baroreceptors and low pressure cardiopulmonary receptors
Rapid control of systemic blood pressure is accomplished or regulated by:
Diastolic Pressure + 1/3 Pulse Pressure
Which of the following best describes MAP?
Aortic Regurgitation
Which of the following can result in blood pressure falling to 0 mmHg between beats?
atrial fibrillation
Which of the following clinical complications is the most common in left atrium enlargement during mitral stenosis?
phosphodiesterase
Which of the following converts cAMP to AMP?
cAMP
Which of the following is an example of a second messenger?
An increase in afterload would be respresented
Stenosis of the aortic valve may result from congenital defects and diseases such as rheumatic fever. What would be the effect on the stenotic aortic valve?
ventricular fibrillation
Sudden shock to the heart, ischemia of the heart muscle or conduction system could cause:
isometric contraction
Tension in the ventricular muscle with no shortening of the muscle fibers is known as:
Stretch of the muscle fibers of the atrial wall directly increases the heart rate by 10-20%
The Bainbridge Reflex is best explained by:
Vascular Tone
The baseline level of constriction within the vessels of the body is known as:
-55 to -70 millivolts
The normal resting membrane potential for Sinus Nodal fibers is
4-6 cm^2
The normal size for the mitral orifice is between:
reception, transduction, and response
The three stages of cell signaling are:
increased contractility
The top line in the figure illustrates the effect of
compliance
The total quantity of blood that can be stored in a vein portion of the circulation for each millimeter of mercury rise in pressure is known as:
70 ml
The volume that is ejected during systole is approximately
Diuretics
These drugs would block active transport of sodium through the tubular walls.
Mitral and Tricuspid valves
These structures prevent backflow into the atria during systole
S-A Node
This area of the heart muscle is where normal rhythm is established
Vasodilators
This drug would act by inhibiting sympathetic nervous signals to the kidneys or by blocking the action of the sympathetic transmitter substance on the renal vasculature.
P-R interval
This interval represents the period between the beginning of contraction of atria and the beginning of contraction of the ventricles.
False
True/False: In endocrine signaling, the signal molecule act on target cell only in close-proximity.
The resting cell membrane has some permeability to Na+
Typical cardiac cell resting membrane potential is actually -90mV because
Decreased activation of nicotinic receptors
What effect will hypocalcemia (Low Ca++) have on the neuromuscular junction?
Protein on the cytoplasmic side of a membrane
What is a G-protein?
surgical reconstruction of valve
What is the best treatment modality for chronic mitral valve regurgitation?
100 mmHg
What is the mean arterial pressure of a blood pressure of 140/80
Shift downward
What will happen to the frank starling curve in a patient with a massive myocardial infarction?
Reduce the K+ diffusion gradient to depolarize the cell
What will hyperkalemia do to the typical cardiac cell resting membrane potential?
isometric contraction
When a muscle doesn't shorten during contraction, this is known as:
As a positive reading (upright)
When action potential travels towards a lead, how is it represented on an EKG?
Vasodilation
When oxygen use increases, what effect will be seen at the vessels?
The Cardiac Output Falls
When total peripheral resistance increases:
B. Potassium chloride
Which agent was given to arrest cardiac function? A. Magnesium choride B. Potassium chloride C. Adenosine D. Sodium chloride
dilation of the left atrium
Which of the following symptoms can result from chronic mitral valve regurgitation?
Glycine
Which of the following would be an example of paracrine signaling in animals?
I bands diminish in size (shorten)
Which of the following would be net result of the sliding filament mechanism?
A. Both
Which of the following would evoke a proportionate change in mean arterial pressure? A. Both B. Stroke Volume C. Neither D. Heart Rate
Abdominal aorta
Which of the following would normally not be an area where baroreceptors would be found?
Blood flow is directly proportional to the pressure difference but inversely proportional to the resistance
Which of the statements best describes blood flow?
Skeletal Pump
Which one of these mechanisms is vital to promote venous return to the heart?
Because it depolarizes muscle and causes inactivation of Na+ channels
Why does hyperkalemia cause skeletal muscle weakness?