What factor is responsible for the movement of the blood in the vascular system?
1. valves in the walls of the blood vessels.
2. peristalsis caused by the smooth muscle in the blood vessel walls.
3. pressure gradients created by the heart.
4. osmotic pressure.
Venous return to the heart would be increased when there is:
1. dilation of the veins.
2. loss of the venous valves.
3. increased skeletal muscle activity.
4. decreased respiratory rate
Which of these pressures pulls water into capillaries?
1. blood hydrostatic pressure
2. blood colloid osmotic pressure
3. interstitial fluid pressure
4. interstitial colloid osmotic pressure
How would the medullary cardiovascular center respond if the blood pressure is increased?
1. increasing the heart rate.
2. sending sympathetic signals to the myocardial cells.
3. increasing cardiac output.
4. causing vasodilation
The regulation of blood pressure is regulated by:
1. hypothalamus
2. medulla oblongata
3. cerebellum
4. pons
What is true regarding the papillary muscles found in the ventricles?
1. They are attached to chordae tendineae.
2. They contract to close the foramen ovale.
3. They are attached to the semilunar valves.
4. They surround the openings of the coronary arteries.
Action potentials pass from one cardiac muscle cell to another
1. through gap junctions.
2. by a special cardiac nervous system.
3. because of the large voltage of the action potentials.
4. because of the plateau phase of the action potentials.
5. by neurotransmitters.
Electrical relay station, slowing the electrical current sent by the sinoatrial (SA) node before the signal is permitted to pass down through to the ventricles, is/are:
1. bundle branches | 2. Purkinje fibers |
3. AV node | 4. AV bundle |
Purkinje fibers are the part of the nodal tissue of the human heart that
1. are specialized cardiac muscle cells.
2. conduct impulses much more slowly than ordinary cardiac muscle.
3. conduct action potentials through the atria.
4. connect between the SA node and the AV node.
T waves on an ECG represent
1. depolarization of the ventricles.
2. repolarization of the ventricles.
3. depolarization of the atria.
4. repolarization of the atria.