Near the end of ventricular systole which of the following a

Near the end of ventricular systole, which of the following are true? a. the AV valves are open and the semilunar valves are closed b. the atria are contracting to fill the ventricles with blood c. no blood is being moved in the heart because all valves are closed d. the pressure in the aorta is at its lowest value e. the AV valves are closed and blood is being ejected from the heart Which of the following is an extrinsic signal the body can use to increase cardiac output? a. decrease parasympathetic activity b. decrease sympathetic activity c. vasodilate peripheral arterials d. release less norepinephrine e. secrete less epinephrine If curve B in the figure to the right is that of a normally functioning heart, what could explain the cause of curve A? a. decreased contractility of the heart b. increased sympathetic activity c. increased parasympathetic activity d. congestive heart failure e. decreased venous return Which of the following is NOT used to control the flow of blood through the arteries? a. hormones (e.g. epinephrine or vasopressin) b. neuronal innervation (e.g. sympathetic) c. paracrine agents (e.g. nitric oxide or prostaglandin) d. metabolic by-products (e.g. O_2 or CO_2) e. all of the above are used What is most responsible for the absorption of interstitial fluid by the venules? a. proteins are present in the blood that are not present in the interstitial space b. the osmotic pressure has changed dramatically between the arteries and the veins c. the hydrostatic pressure in the veins has dropped below that of the interstitial space d. filtration has dramatically increased the hydrostatic pressure in the interstitial space e. the headache that this question is causing increases net absorption rates

Solution

Que 12:

Ans:

Near the end of ventricular systole,

d) the pressure in the aorta is at its lowest value.

Explanation:

- At the end of ventricular systole, the pressure falls and there is another reflection of recording, indicating aortic valve closure.

- Ventricular pressure then falls to its lowest level and the AV valves open, yhus starting another cycle of contraction in the heart.