Exercise Effects on Heart Practice Questions
20 free Exercise Effects on Heart practice questions for the Physiology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
The primary function of the cardiovascular system is to:
- A Produce and secrete hormones
- B Transport substances around the body
- C Regulate overall core body temperature
- D Generate adaptive immune responses
Correct answer: Transport substances around the body
The cardiovascular system transports oxygen, nutrients, hormones, and waste products. This transport function is essential for maintaining cellular homeostasis.
Cardiac output is defined as the:
- A Volume of blood pumped per beat
- B Volume of blood pumped per minute
- C Pressure generated during systole
- D Total blood volume in circulation
Correct answer: Volume of blood pumped per minute
Cardiac output is the product of heart rate and stroke volume. It represents the amount of blood pumped by the heart each minute.
Which heart chamber has the thickest wall?
- A Right atrium
- B Left atrium
- C Right ventricle
- D Left ventricle
Correct answer: Left ventricle
The left ventricle has the thickest wall because it pumps blood to the systemic circulation. This requires generating high pressure.
Stroke volume is the amount of blood ejected from the ventricle during:
- A Diastole
- B Atrial systole
- C Ventricular systole
- D Isovolumetric relaxation
Correct answer: Ventricular systole
Stroke volume is the volume of blood ejected during ventricular systole. It is a key determinant of cardiac output.
Which valve prevents backflow of blood from the left ventricle into the left atrium?
- A Aortic valve
- B Pulmonary valve
- C Mitral valve
- D Tricuspid valve
Correct answer: Mitral valve
The mitral valve separates the left atrium and left ventricle. It prevents regurgitation during ventricular systole.
The pacemaker of the heart is the:
- A Atrioventricular node
- B Purkinje fibers
- C Sinoatrial node
- D Bundle of His
Correct answer: Sinoatrial node
The sinoatrial node generates spontaneous electrical impulses. It sets the normal heart rhythm.
The P wave of an electrocardiogram represents:
- A Ventricular depolarization
- B Atrial depolarization
- C Ventricular repolarization
- D Atrial repolarization
Correct answer: Atrial depolarization
The P wave reflects depolarization of the atria. This electrical event leads to atrial contraction.
Which factor primarily determines diastolic blood pressure?
- A Stroke volume of the ventricle
- B Resting heart rate
- C Peripheral resistance
- D Circulating blood volume
Correct answer: Peripheral resistance
Diastolic blood pressure mainly depends on peripheral vascular resistance. Arteriolar tone plays a key role.
Mean arterial pressure is best approximated by:
- A Systolic pressure minus the diastolic pressure value
- B Diastolic pressure plus one-third pulse pressure
- C Simple average of systolic and diastolic pressure
- D Systolic pressure plus pulse pressure
Correct answer: Diastolic pressure plus one-third pulse pressure
Mean arterial pressure reflects average driving pressure for blood flow. It is calculated as diastolic pressure plus one-third of pulse pressure.
Which vessel has the highest blood pressure?
- A Capillaries
- B Veins
- C Arterioles
- D Aorta
Correct answer: Aorta
The aorta experiences the highest pressure as it receives blood directly from the left ventricle. Pressure falls progressively in distal vessels.
Pulse pressure is defined as the difference between:
- A Difference between mean and diastolic pressure
- B Systolic and diastolic pressure
- C Difference between mean and systolic pressure
- D Difference between venous and arterial pressure
Correct answer: Systolic and diastolic pressure
Pulse pressure equals systolic minus diastolic pressure. It reflects stroke volume and arterial compliance.
The primary site of exchange of gases and nutrients is the:
- A Arteries
- B Veins
- C Capillaries and venules
- D Arterioles
Correct answer: Capillaries and venules
Capillaries have thin walls that allow diffusion of gases and nutrients. They form extensive networks within tissues.
Which mechanism contributes most to venous return during exercise?
- A Venous valves
- B Muscle pump
- C Gravity
- D Arterial recoil
Correct answer: Muscle pump
Contraction of skeletal muscles compresses veins and propels blood toward the heart. This muscle pump greatly enhances venous return.
According to the Frank-Starling law, increased venous return results in:
- A Decreased stroke volume of the ventricle
- B Increased heart rate only
- C Increased force of contraction
- D Reduced overall cardiac output
Correct answer: Increased force of contraction
Increased venous return stretches cardiac muscle fibers. This leads to stronger contraction and higher stroke volume.
Which blood vessel acts as the primary resistance vessel?
- A Arteries
- B Veins
- C Capillaries
- D Arterioles
Correct answer: Arterioles
Arterioles have adjustable diameters that regulate blood flow. They are the main contributors to peripheral resistance.
The QRS complex of the ECG corresponds to:
- A Atrial depolarization
- B Atrial repolarization
- C Ventricular depolarization
- D Ventricular repolarization
Correct answer: Ventricular depolarization
The QRS complex represents rapid depolarization of the ventricles. This electrical event triggers ventricular contraction.
Which factor decreases heart rate?
- A Increased sympathetic stimulation
- B Parasympathetic stimulation
- C Increased venous return
- D Increased body temperature
Correct answer: Parasympathetic stimulation
Parasympathetic activity via the vagus nerve slows heart rate. It reduces the firing rate of the sinoatrial node.
Which condition is characterized by elevated arterial blood pressure?
- A Hypotension
- B Hypertension
- C Myocardial ischemia
- D Circulatory shock
Correct answer: Hypertension
Hypertension refers to persistently high arterial blood pressure. It increases the risk of cardiovascular disease.
Coronary blood flow primarily occurs during:
- A Ventricular systole
- B Isovolumetric contraction
- C Ventricular diastole
- D Atrial systole
Correct answer: Ventricular diastole
Coronary vessels are compressed during systole. Blood flow to the myocardium mainly occurs during diastole.
Which factor has the greatest influence on blood flow through a vessel?
- A Blood viscosity
- B Vessel length
- C Pressure gradient
- D Vessel radius
Correct answer: Vessel radius
According to Poiseuille’s law, flow is proportional to the fourth power of vessel radius. Small changes in radius greatly affect flow.