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?