Straighterline A&P II Quiz 2 with Complete Solutions

Straighterline A&P II Quiz 2 with Complete Solutions What event(s) occur during the QRS complex of an ECG? a. depolarization of the atria b. repolarization of the ventricles c. depolarization of the atria and repolarization of the ventricles d. depolarization of the ventricles and repolarization of the atria -Answer-d. depolarization of the ventricles and repolarization of the atria Blood in the pulmonary veins returns to the a. right atrium. b. left atrium. c. right ventricle. d. left ventricle. e. coronary sinus. -Answer-b. left atrium. The "pacemaker" of the heart is the a. right bundle branch. b. left bundle branch. c. AV node. d. SA node. e. PM node. -Answer-d. SA node. The great cardiac vein and middle cardiac vein empty into a venous cavity called the a. pulmonary vein. b. inferior vena cava. c. superior vena cava. d. coronary sinus. e. coronary artery. -Answer-d. coronary sinus. Lowered extracellular potassium levels will lower the heart rate because a. the resting membrane potential is hyperpolarized. b. ectopic action potentials occur. c. action potential amplitude declines. d. more sodium channels open. e. it blocks calcium channels. -Answer-a. the resting membrane potential is hyperpolarized. Which vessels empty blood into the left atrium? a. aorta b. right atrium c. pulmonary trunk d. pulmonary arteries e. pulmonary veins -Answer-e. pulmonary veins The plateau phase seen during the action potential of a cardiac muscle cell is due to the a. sodium-potassium pump. b. opening of sodium channels. c. continuing to have open calcium channels. d. closure of chloride channels. e. closing of calcium channels. -Answer-c. continuing to have open calcium channels. When a pacemaker potential in the SA node reaches threshold, a. the permeability to K+ ions increases. b. many voltage-gated Ca2+ channels open. c. voltage-gated Ca2+ channels close. d. RMP has been restored. e. permeability of the cell does not change. -Answer-b. many voltage-gated Ca2+ channels open. The AV valve that is located on the same side of the heart as the origin of the aorta is the a. bicuspid or mitral valve. b. tricuspid valve. c. aortic semilunar valve. d. pulmonary semilunar valve. e. coronary sinus valve. -Answer-a. bicuspid or mitral valve. Which of the following is NOT a major opening into the right atrium? a. pulmonary vein b. inferior vena cava c. superior vena cava d. coronary sinus -Answer-a. pulmonary vein Which of the following might increase the risk for cardiovascular disease? a. stopping smoking b. exercise c. maintaining normal cholesterol levels d. chronic stress e. lots of fiber in the diet -Answer-d. chronic stress What cardiac arrhythmia will have no QRS complex as a symptom? a. atrial fibrillation b. ventricular fibrillation c. bradycardia d. premature ventricular contractions -Answer-b. ventricular fibrillation Fred was admitted to the cardiac unit with chest pains. No arrhythmias and no large changes in the heart rate were observable. Blood samples taken over the next few days showed no increase in enzymes such as creatine phosphokinase. A possible treatment of the condition is a. beta adrenergic blocking agents. b. nitroglycerin. c. calcium channel blocking agents. d. aspirin. e. exercise. -Answer-b. nitroglycerin. Calcium channel blockers are frequently used to a. increase the heart rate. b. treat tachycardia or other arrhythmias. c. speed up conduction of impulses through the AV node. d. slow the closing of potassium ion channels. e. treat bradycardia and low blood pressure. -Answer-b. treat tachycardia or other arrhythmias. What abnormal heart rhythm could be caused by an elevated body temperature, excessive sympathetic stimulation, or toxic conditions?