Cardiovascular Physiology Quiz

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What neurotransmitter is released by the cardio-acceleratory centre to increase heart rate?

Dopamine
Acetylcholine
Serotonin
Noradrenaline (correct)

Through which nerve does the cardio-inhibitory centre communicate with the sinoatrial node?

Adrenal nerve
Phrenic nerve
Sympathetic nerve
Vagus nerve (correct)

What effect does the vagus nerve have on heart rate?

Causes arrhythmia
Decreases heart rate (correct)
Increases heart rate
Has no effect on heart rate

Which part of the brain houses the cardiovascular centre responsible for heart rate regulation?

Medulla oblongata (A) Signup and view all the answers

What is the primary role of stretch receptors in muscles in relation to the cardiovascular centre?

To send signals about muscular activity (C) Signup and view all the answers

During which stage of the cardiac cycle are the ventricles contracting?

Stage B (B) Signup and view all the answers

What is the total duration for the ventricles being relaxed over a one-minute period with a heartbeat of 60 beats per minute?

48 seconds (C) Signup and view all the answers

What is the time duration of Stage B in the cardiac cycle?

0.1-0.3 seconds (C) Signup and view all the answers

In which stage of the cardiac cycle are the atria relaxing and the ventricles relaxing?

Stage C (B) Signup and view all the answers

If the heart is beating at 60 beats per minute, how many seconds are the atria contracting in total during one minute?

10 seconds (A) Signup and view all the answers

Which factor directly triggers an increased heart rate through hormonal response?

Releases of adrenaline (D) Signup and view all the answers

How do chemoreceptors influence heart rate when CO₂ levels rise?

By sending signals to the cardiovascular centre (C) Signup and view all the answers

What effect does increased blood pressure have on heart rate regulation?

It activates baroreceptors to signal the need for reduced heart rate. (D) Signup and view all the answers

What physiological response occurs due to muscular movement in relation to heart function?

Muscles increase the pressure in veins, aiding blood return to the heart. (A) Signup and view all the answers

Which statement accurately describes the role of the medulla oblongata in heart rate regulation?

It coordinates responses from both chemoreceptors and baroreceptors for heart rate adjustments. (D) Signup and view all the answers

What is the purpose of the AV valve in the heart?

To prevent backflow from the ventricles to the atria (D) Signup and view all the answers

How do the tendinous cords function within the heart?

They prevent the valves from inverting during contraction (A) Signup and view all the answers

What could happen if the AV valve were to malfunction?

Backflow of blood into the atria (B) Signup and view all the answers

Which component of the heart ensures unidirectional blood flow during the cardiac cycle?

AV valves and tendinous cords (D) Signup and view all the answers

If tendinous cords were damaged, what is the most likely effect on heart function?

The valves may invert during contraction (D) Signup and view all the answers

What is the primary function of the coronary artery?

To supply oxygen to the heart (B) Signup and view all the answers

Which blood vessel is the origin of the coronary artery?

Aorta (B) Signup and view all the answers

During which phase of the cardiac cycle do the atrioventricular valves open?

Ventricles are relaxed (B) Signup and view all the answers

Which event occurs when the ventricles are emptying?

Blood pressure in the ventricles decreases (A) Signup and view all the answers

What happens to the semilunar valves during the cardiac cycle?

They open when the ventricles are contracting (A) Signup and view all the answers

What is the primary reason the left ventricle has thicker walls than the right ventricle?

It pumps blood at a higher pressure around the body. (C) Signup and view all the answers

What characteristic do the left and right ventricles share regarding their blood output?

They both pump equal volumes of blood with each beat. (C) Signup and view all the answers

Which of the following accurately describes blood flow through a mammalian heart?

The right atrium receives deoxygenated blood from the systemic circulation. (C) Signup and view all the answers

Which statement best describes the role of the left atrium in the heart?

It collects oxygenated blood from the pulmonary veins. (C) Signup and view all the answers

Why is it crucial for the left and right ventricles to pump equal volumes of blood?

To avoid backup in one of the circulatory systems. (C) Signup and view all the answers

What occurs in the left ventricle between times P and Q during the cardiac cycle?

The volume of the left ventricle decreases. (C) Signup and view all the answers

At what point does the semilunar valve open in the cardiac cycle?

At point P, allowing blood to leave the left ventricle. (A) Signup and view all the answers

What is the significance of the decreasing volume in the left ventricle as observed from times P to Q?

It signifies the end of the cardiac cycle. (C) Signup and view all the answers

How does the pressure in the left ventricle change during times P to Q?

It gradually decreases as blood is ejected from the ventricle. (A) Signup and view all the answers

What is primarily responsible for the decrease in volume of the left ventricle during the cardiac cycle?

Blood ejecting from the left ventricle into the aorta. (B) Signup and view all the answers

What is the primary function of the sinoatrial node (SAN) in the heart?

To generate electrical impulses that regulate the heartbeat (A) Signup and view all the answers

Why is the atrioventricular node (AVN) important in the cardiac cycle?

It acts as a delay to ensure efficient pumping (B) Signup and view all the answers

What consequence would occur if there were no time delay for depolarization to travel from the atria to the ventricles?

The ventricles would contract too early (A) Signup and view all the answers

Which of the following best describes the process of depolarization in the heart?

A wave of depolarization begins at the SAN and spreads to the AVN (D) Signup and view all the answers

What role does the sinoatrial node play in a healthy heart rhythm?

It sets the pace of the heartbeat through rhythmic electrical signals (A) Signup and view all the answers

Cardiovascular Center

A group of specialized cells in the medulla oblongata that regulate heart rate and blood pressure.

Baroreceptors

Receptors in the aorta and carotid arteries that detect changes in blood pressure.

Chemoreceptors

Receptors located in the aorta, carotid arteries, and medulla oblongata that detect changes in CO₂ levels.

Parasympathetic Nerve

The nerve that carries signals from the cardiovascular center to the heart, slowing down heart rate.