Which statement best compares an echocardiogram and a Doppler flow study? A. Both are used to evaluate chemicals produced by the heart.
B. Both involve the removal and testing of heart tissue.
C. Both utilize sounds waves to produce images of the heart.
D. Both require doctors to analyze electrical impulses produced by the heart.

Agroup of 50 adult male humans were in a clinical study to determine how much niacin is toxic. during the first two weeks of the study, members of the group consumed only a formula diet that was nutritionally complete, except it contained 24 mg niacin, which is 1.5 times the rda for niacin (males). at that point in the study, all members reported feeling fine. during the next week, they were given a formula that contained 48 mg niacin. within a few days of consuming this formula, 90% of the participants reported feeling ill, and they complained of having upset stomachs and reddened facial skin. at that point, researchers gave the subjects a formula that contain 16 mg niacin. after a week of consuming the new formula, all participants reported feeling well again. based on this information, the researchers concluded that the amdr for niacin is between 16 and 24 mg/day. ul for niacin was between 24 and 48 mg/day. human requirement for niacin is 16 mg/day. eer for niacin was 16 mg/day.

A46-year-old man with a history of hypertension and hypercholesterolemia visits the physician for a routine followup. the patient's job involves a lot of travelling, and he admits to occasionally forgetting to take his medications with him when he travels. he complains of several episodes of chest pain in the past few months. the pain is sharp in nature, mainly over his lower chest and epigastrium, and tends to come on when walking. he believes these episodes are due to indigestion and has been taking antacids. there is a family history of heart disease, and his father died of a heart attack at age 48. on physical examination, his blood pressure is 150/80 mmhg and heart rate is 86/min. his lungs are clear to auscultation. cardiac auscultation reveals normal rate and rhythm, without rubs, gallops, or murmurs. there is no pedal oedema. he is sent for an exercise stress test. five minutes into the test, he develops st depression of 3mm in leads v1-v5. the st segment depression is greater than 0.12 seconds in duration and the stress test is stopped. which of the following is the most appropriate next step in management? - coronary angiography- holter monitor- no further tests are required- repeat stress test with thallium- upper gastrointestinal endoscopy

Define physical activity. question 3 options: bodily movement produced by the contraction of muscles planned and structured exercise the ability to perform rigorous activity all the above