Circulatory System and Human Heart

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Questions and Answers

Which types of blood vessels carry blood away from the heart?

Capillaries

Veins

Venules

Arteries (correct)

What is the primary function of red blood cells (RBCs)?

To transport carbon dioxide

To transport oxygen (correct)

To fight infections

To carry nutrients

What is the structure surrounding the heart that provides protection and support?

Myocardium

Epicardium

Pericardium (correct)

Endocardium

Which component of the circulatory system helps in immunity?

White blood cells Signup and view all the answers

What type of circulation is described by blood flowing through the heart and body twice during a complete cycle?

Double circulation Signup and view all the answers

What is the primary function of the Sinoatrial node (SA node)?

To generate electrical impulses coordinating heartbeats Signup and view all the answers

Which vessel carries deoxygenated blood from the body to the right auricle?

Superior vena cava Signup and view all the answers

What type of blood do pulmonary veins carry to the left auricle?

Oxygenated blood Signup and view all the answers

Which statement correctly describes the function of the aorta?

It distributes oxygenated blood to all parts of the body except the lungs Signup and view all the answers

What type of blood do coronary arteries supply?

Oxygenated blood Signup and view all the answers

How does the heart receive deoxygenated blood from the lower body?

Through the inferior vena cava Signup and view all the answers

Which blood vessels do NOT contain valves?

Pulmonary veins Signup and view all the answers

What is the term used to describe the contraction phase of the heart?

Systole Signup and view all the answers

During which phase does blood flow into the ventricles from the auricles?

Diastole Signup and view all the answers

What is the average normal heart rate for a healthy adult?

70-75 beats per minute Signup and view all the answers

What does blood pressure measure?

The force of blood against arterial walls Signup and view all the answers

What is the normal blood pressure reading in adults, typically expressed in mm Hg?

120/80 mm Hg Signup and view all the answers

What produces the second sound during the heartbeat that is stronger than the first?

Contraction of the ventricles Signup and view all the answers

Which instrument is used to measure blood pressure?

Sphygmomanometer Signup and view all the answers

What does the term 'pulse' refer to?

The rate of heartbeats felt in the arteries Signup and view all the answers

Which part of the body is most common for feeling the pulse?

The wrist Signup and view all the answers

What is the role of the pulmonary veins in the circulatory process?

They transport oxygenated blood back to the heart. Signup and view all the answers

Which statement correctly describes systemic circulation?

It supplies oxygenated blood from the left ventricle to body parts. Signup and view all the answers

During the cardiac cycle, what happens after the ventricles are filled?

The valves close and the ventricles contract. Signup and view all the answers

What completes the process of double circulation?

Blood circulating through both the heart and lungs. Signup and view all the answers

Which structure carries deoxygenated blood to the lungs?

Pulmonary arteries Signup and view all the answers

What occurs when blood passes through capillaries?

Nutrients are delivered to the cells. Signup and view all the answers

What is the function of the aorta in the circulatory system?

It distributes oxygenated blood to the body tissues. Signup and view all the answers

Which of the following describes a characteristic of the heart's contraction?

The ventricles contract after the atria. Signup and view all the answers

What occurs to the blood once it passes through body capillaries?

It is deoxygenated and returns to the right auricle. Signup and view all the answers

Study Notes

Circulatory System in Humans

The circulatory system transports nutrients, gases, and hormones throughout the body.
Blood is a fluid connective tissue composed of plasma and blood cells (RBCs, WBCs, platelets).
RBCs contain haemoglobin, which gives them their red colour.
WBCs are larger than RBCs and do not contain haemoglobin.
Blood platelets are colourless, disc-shaped cells without nuclei.
Blood vessels (arteries, veins, capillaries) carry blood throughout the body.
Arteries carry blood away from the heart, veins carry blood towards the heart, and capillaries connect arteries and veins.

The Human Heart

The heart is a pear-shaped muscular organ located in the chest cavity.
An adult heart is approximately 12 cm long and 9 cm wide, weighing about 300 g.
The heart has four chambers: two auricles (atria) and two ventricles.
Auricles receive blood; ventricles pump blood.
The septum separates the right and left sides of the heart, preventing the mixing of oxygenated and deoxygenated blood.
Valves control the flow of blood in one direction. (tricuspid, bicuspid, pulmonary, aortic)

Chambers of the Heart

Auricles (atria) are the upper chambers, have thin walls, and receive blood.
Ventricles are the lower chambers, have thick walls, and pump blood.

Heart's Natural Pacemaker

The Sinoatrial (SA) node is the heart's natural pacemaker, located in the upper right auricle.
It coordinates heartbeats by generating electrical impulses.

Blood Vessels in the Heart

Vena cavae carry deoxygenated blood from the body to the heart.
Superior vena cava from the upper body, inferior vena cava from the lower body.
Coronary arteries supply the heart muscle (myocardium).
Coronary veins return deoxygenated blood to the right atrium.

Double Circulation

Blood passes through the heart twice in one complete circuit.
Pulmonary circulation: blood travels from the right ventricle to the lungs and then to the left atrium.
Systemic circulation: blood travels from the left ventricle to the body and then to the right atrium.

Heartbeat and Cardiac Cycle

The heart's muscles contract and relax rhythmically.
The sequence of events in one complete heartbeat is called the cardiac cycle.
Systole is contraction, diastole is relaxation.

Blood Pressure

Blood pressure is the force of blood exerted against the arterial walls.
Systolic pressure is the pressure during ventricular contraction.
Diastolic pressure is the pressure during ventricular relaxation.

Abnormal Heart Functioning

Palpitations (rapid or irregular heartbeat).
Cardiac arrest (sudden stop of heart contractions).
Hypertension (high blood pressure).

Blood Groups

Antigens (proteins) on the surface of red blood cells (RBCs).
Antibodies (proteins) in the blood plasma.
ABO blood groups (A, B, AB, O).
Universal donor: O
Universal recipient: AB

Rhesus Factor

Another antigen found on RBCs.
Rh+ (positive) has the antigen, Rh- (negative) does not.
Incompatible blood transfusions can lead to complications.

Lymphatic System

Consists of lymph vessels and lymph nodes.
Lymph is a fluid similar to blood plasma, but without RBCs and platelets.
Functions: Transportation (nutrients, hormones, waste removal), defense (fights infections), drainage (removes excess tissue fluid).

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Description

Test your knowledge on the circulatory system and the human heart. This quiz covers the structure, function, and components of blood, as well as the anatomy of the heart. Understand how these systems work together to sustain life.