practice questions from downey

TRUE OR FALSE: Gap junctions are found both on the mitochondria inner membrane and the mitochondrial outer membrane.

FALSE

TRUE OR FALSE: Autonomic regulation of heart rate is via two reflex centers found in the mediastinum.

FALSE - This tests your knowledge of the location of the cardiac centres. They are in the medulla oblongata. The mediastinum is the space in the chest where the heart is!

TRUE OR FALSE: Cardiac muscle has more mitochondria and depends less on a continual supply of oxygen than does skeletal muscle.

False - first part is true, second part is false. Mitochondria and oxygen are linked.

TRUE OR FALSE: The "lub" sounds of the heart are valuable in diagnosis because they provide information about the function of the heart's pulmonary and aortic semilunar valves.

False. This would be true if the Lub was changed to Dub or, alternatively, if the last sentence refered to the AV valves

TRUE OR FALSE: When released in large quantities, thyroxine, a thyroid gland hormone, causes a sustained increase in heart rate.

True - increases body metabolism and potentiates effects of norepinephrine

Exercise results in skeletal muscles compressing veins which encourages blood to return to the heart. In this scenario, which of the following is correct? a) preload increases b) venous return decreases c) end diastolic volume (EDV) decreases d) stroke volume decreases

a

Normal heart sounds are caused by which of the events? A) closure of the heart valves B) friction of blood against the chamber walls C) excitation of the sinoatrial (SA) node in the intrinsic conduction system D) opening of the heart valves E) Stenotic valve

a

Your doctor listens to your chest. She hears a clicking sound around your heart. This could be due to: a) Decreased Cardiac output b) Stenotic AV valve c) Incompetent SL valve d) Low levels of calcium

b

Cardiac Output: a) Is equal to HR/SV b) Is affected by ESV but not EDV c) Is equal to SV x HR d) Is not impacted by calcium

c

Which of the following items is NOT part of the intrinsic conduction system of the heart? A) atrioventricular (AV) node B) bundle branches C) atrioventricular (AV) valve D) sinoatrial (SA) node E) All of the above F) None of the above

c

The Frank-Starling Law states that: A) higher end diastolic volume will produce a lower stroke volume B) higher stroke volume will produce a higher end diastolic volume C) higher stroke volume will produce a lower end diastolic volume D) higher end diastolic volume will produce a higher stroke volume E) None of the above

d

What is true about electrocardiograms? a) The P wave represents ventricle depolarization b) The atrial repolarization is hidden in the QRS peak c) The P wave is always half the height of the QRS peak d) The T wave represents atrial repolarization e) None of the above are true statements f) All of the above are true statements

e

The second messenger cAMP is: A) Required for kinase inhibition. B) Closes calcium channels C) Is released from the ER. D) A and B E) None of the above

e, cAMP is an activator

TRUE OR FALSE: Cardiac Cells have more endoplasmic reticulum than skeletal muscle cells

false

True or False: Tachycardia is an increase in systolic pressure

false