Cardiac Anatomy & Physiology Quiz

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Questions and Answers

What is the primary function of the heart in the cardiovascular system?

To deliver oxygenated blood and deoxygenated blood for gas exchange (correct)

To drive blood to the capillaries only

To produce lymph for the lymphatic system

To filter blood and cleanse it of impurities

Which statement accurately describes the structure of the heart?

It is cone-shaped and about the size of a clenched fist (correct)

It is situated in the lower abdomen

It is flat-shaped like a pancake

It is located on the right side of the chest

Why is the circulatory system described as a closed system?

Blood is contained within the heart and blood vessels at all times (correct)

Blood flows in both directions within the same vessels

Blood is never contained within the heart

Blood is able to leave the circulatory system through the lymphatic vessels

What components make up the circulatory system?

The heart, blood, and lymphatic system Signup and view all the answers

What substances are delivered by the circulatory system to the body's cells?

Nutrients, oxygen, and hormones Signup and view all the answers

What is the formula used to calculate stroke volume (SV)?

SV = End Diastolic Volume - End Systolic Volume Signup and view all the answers

Which measurement indicates how much blood is pumped out of the heart per minute?

Cardiac Output Signup and view all the answers

At what volume is the End Diastolic Volume (EDV) noted in the heart's cycle provided?

125 mls Signup and view all the answers

What is the approximate stroke volume in a healthy adult male?

75 mls Signup and view all the answers

What is the relationship between cardiac output, heart rate, and stroke volume?

Cardiac Output = Heart Rate x Stroke Volume Signup and view all the answers

What is the primary function of the pulmonary circuit?

Circulate blood between the heart and lungs Signup and view all the answers

What is the role of the SA node in the heart?

To generate electrical impulses that initiate heartbeats Signup and view all the answers

Which term describes the contraction phase of the heart cycle?

Systole Signup and view all the answers

How is stroke volume calculated?

End diastolic volume minus end systolic volume Signup and view all the answers

What would be considered a normal cardiac output for a healthy resting adult?

5-6 litres per minute Signup and view all the answers

What does the ejection fraction indicate?

The percentage of blood leaving the heart upon contraction Signup and view all the answers

Which structures are responsible for ensuring one-way blood flow in the heart?

Heart valves Signup and view all the answers

Which area of the heart has the highest rate of impulse generation?

SA node Signup and view all the answers

Study Notes

Circulatory System Overview

The heart is a hollow muscular organ that functions as a pump in the circulatory system.
The circulatory system comprises the cardiovascular and lymphatic systems, which manage blood flow and lymph throughout the body.
Key functions include transporting oxygen, nutrients, hormones, and gases to and from cells.

The Heart Structure

Located centrally between the lungs, slightly to the left; roughly the size of a clenched fist.
Functions continuously, never stopping its pumping action.
Comprised of four chambers: two atria receive blood, and two ventricles pump blood.
Surrounded by myocardial cells, enabling contraction and relaxation.

Cardiovascular System Components

Contains approximately 4-6 liters of blood in a closed system, where blood remains within vessels at all times.
Blood travels through arteries, arterioles, capillaries, and veins.
Blood flow patterns include:
- Pulmonary circuit: Blood flow between heart and lungs.
- Systemic circuit: Blood flow to and from the rest of the body.
- Coronary circuit: Blood flow to the heart itself.

Heart Functionality

Heart valves facilitate unidirectional blood flow.
The contraction process of the heart is termed systole, while relaxation is known as diastole.

Cardiac Cycle and Key Terms

End Diastolic Volume (EDV): Blood volume in ventricles at end of filling (approximately 125 mls).
End Systolic Volume (ESV): Blood volume remaining in ventricles at end of contraction (approximately 50 mls).
Stroke volume (SV): Volume of blood pumped from ventricles per beat, averaging 70 mls in a healthy adult male.
Formula for stroke volume: EDV - ESV = SV (e.g., 125 ml - 50 ml = 75 ml).

Cardiac Output (CO)

Cardiac output refers to the blood ejected by the heart per minute, averaging 5-6 liters in a healthy adult at rest.
Formula: CO = Heart Rate x Stroke Volume.
Example calculation: CO = 70 bpm x 75 mls = 5,250 mls.

Conduction System of the Heart

Two types of cardiac cells (myocytes):
- Myocardial Cells: Contractile cells that respond to electrical impulses.
- Specialized Cells: Form the conduction system that generates and transmits electrical impulses.
Main impulse generation sites and rates:
- SA Node: 60-100 impulses/min
- AV Node: 40-60 impulses/min
- Ventricles: < 40 impulses/min

Ejection Fraction

Ejection fraction measures the percentage of blood pumped out of the heart with each contraction.
Typically assessed via imaging techniques such as ECHO, cardiac catheterization, or MRI.
Both cardiac output and ejection fraction are crucial indicators of heart efficiency in meeting the body's metabolic demands.

Balance of Blood Output

The output from the right and left sides of the heart must be balanced.
The ventricles do not completely empty, ensuring continual blood flow.
Key values:
- End Diastolic Volume: 125 mls
- End Systolic Volume: 50 mls
- Example SV Calculation: 125 mls - 50 mls = 75 mls.

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Description

Test your knowledge on the anatomy and physiology of the heart and the circulatory system. This quiz covers essential concepts about how the heart functions as a pump and its role in the cardiovascular system. Prepare to explore the intricate connections between the heart, blood, and nutrients.