PhysioEx Exercise 6

Delivering single shocks in succession to stimulate the frog heart _______.

The doublet that results with more frequent stimulation of the frog heart represents _______.

When the ventricles beat rapidly in succession, _______.

When multiple stimuli were applied at 20 stimuli/sec, _______.

The autorhythmicity of cardiac pacemaker cells is made possible by the reduced permeability of _______.

The repolarization of cardiac muscle is due to _______.

The total refractory period of cardiac muscle _______.

Skeletal muscle is capable of which of the following?

When vagus nerve stimulation was applied to the frog heart, _______.

What part of your tracing illustrates vagal escape?

Research shows that in the absence of neural and hormonal influences, the SA node generates action potentials at a frequency of about 100 times per minute. However, the resting heart rate is about 70 beats per minute. What would the approximate heart rate be if the vagus nerve were severed?

Which of the following has the fastest rate of spontaneous depolarization?

The effect of the sympathetic nervous system on the heart is to _______.

Which branch of the autonomic nervous system dominates after a large meal?

The sinoatrial node is located _______.

Excessive vagal stimulation of the heart will result in _______.

For the frog heart, temperature and heart rate are _______.

If the human heart were experiencing hyperthermia, what do you think would be the effect on the heart rate?

Ringer's solution contains which of the following?

Organisms that are poikilothermic _______.

Which part of the human body regulates temperature?

Heat-releasing mechanisms include which of the following?

Muscarine is a poison found in poisonous mushrooms. Muscarine binds to acetylcholine receptors and mimics its action. Which of the following describes the effect of muscarine?

Beta blockers are used to treat high blood pressure (hypertension). Which receptors do you think are being blocked?

With respect to heart rate, which of the following worked in opposition to each other?

With respect to heart rate, which of the following had the same effect?

Which of the following affect heart rate through the use of a cAMP (second messenger) system?

Which of the following decreases the rate of depolarization in the heart?

The sinoatrial node has receptors for _______.

An adrenergic drug that worked in opposition to epinephrine would _______.

Which ion(s) at least initially lowered the frog heart rate in the activity you just performed?

What effect does potassium have on the resting membrane potential of the cardiac cell?

The cardiac cell plasma membrane is most permeable to _______________________.

Calcium channel blockers block the movement of calcium _______.

A ___________________ drug increases the force of contraction of the heart.

When the cardiac muscle cell is at rest, the concentration of _____________ is greater on the outside of the cell.

Modifiers that affect the force of contraction of the heart are _______.

The movement of _______________ into the cardiac muscle cell depolarizes the cardiac muscle cell.

Modifiers that affect heart rate are _______.