The left ventricle pumps blood to the A lungs B right ventri

The left ventricle pumps blood to the A) lungs. B) right ventricle. C) right atrium. D) aorta. E) pulmonary circuit. Contractions of the papillary muscles A) close the atrioventricular valves. B) close the semilunar valves. C) eject blood from the ventricles. D) prevent the atrioventricular valves from reversing into the atria. E) eject blood from the atria into the ventricles. Complications related to arteriosclerosis account for roughly__percent of deaths in the United States. A) 30 B) 60 C) 50 D) 20 E) 25 The relaxation phase of the lower chambers of the heart is called A) ventricular systole. B) ventricular diastole. C) atrial systole. D) atrial diastole. E) None of the answers is correct. At a heart rate of 60 A) 60 seconds. B) 60 milliseconds. C) 1 second. D) 370 milliseconds. E) 630 milliseconds.

Solution

9. The left ventricle pumps blood to the

Ans: D (Aorta) The left ventricle recieves the oxygenated blood from the left auricle (which gets from left lung) pumps the bloos to Aorta whihc pumps the blood to the body parts.

10. Contractions of the papillary muscles:

Ans: D (prevent the atrioventricular valves from reversing into atria). Papillary muscles extend from walls of the ventricle sto atriovetricular valves. They attache to these valves and contracts to prevent the backward flow of the blood from ventricles to atria.

11. Percentage of deaths in USA due to arteriosclerosis:

Ans: E (25%) This disease is caused at old age mainly. Due to this disease the walls of the arteries becaome thick and become less elastic to pump blood, which leads to death.

12. The relaxtion phase of lower chambers of heart is called:

Ans: B (Ventricular diastole) The relaxation of lower chambers ie., ventricles is termed as ventricular diastole, where ventricles are relaxed accepting the blood from auricles.

13. At a heart rate of 60 beats/minute, a cardiac cycle lasts

Ans: C (1 sec) The cardiac cycle last for 1sec.

As heart rate is 60 beats/ minute ie., 60 times heart beats in one minute (which is equal to 60 seconds). One heart beat is nothing but all the stages of cardiac cycles. So for one heart beat it takes 1 second. ie., for one cardiac cycle the time taken is 1sec.