Cambridge (CIE) IGCSE Biology: Circulatory Systems, Heart & Blood Vessels Flashcards

These vocabulary flashcards cover the primary components, structures, and processes of the mammalian and fish circulatory systems as described in the Cambridge (CIE) IGCSE Biology notes.

Circulatory system

An organ system whose role is to transport blood around the body, consisting of blood vessels, a pump, and valves.

Single circulation

A system where blood passes through the heart once for every one circuit of the body, characteristic of fish with their two-chambered hearts.

Double circulation

A system where blood passes through the heart twice for every one circuit of the body, characteristic of mammals with four-chambered hearts.

Pulmonary circulation

The circulation where the right side of the heart receives deoxygenated blood from the body and pumps it to the lungs.

Systemic circulation

The circulation where the left side of the heart receives oxygenated blood from the lungs and pumps it to the rest of the body.

Septum

A muscle wall that separates the two sides of the heart to prevent the mixing of oxygenated and deoxygenated blood.

Coronary arteries

Vessels that supply the heart's muscle tissue with blood containing oxygen, glucose, and other nutrients.

Plaques

Fatty deposits, mainly formed from cholesterol, that can partially or completely block coronary arteries.

Angina

Severe chest pains resulting from restricted blood flow to the cardiac muscle cells due to partial blockage of the coronary arteries.

Heart attack

A medical emergency occurring when a complete blockage of a coronary artery prevents cardiac muscle cells from respiring and contracting.

Atrioventricular valves

Valves that separate the atria from the ventricles, including the tricuspid valve on the right and the bicuspid valve on the left.

Semilunar valves

Valves found in the pulmonary artery and the aorta that open during ventricular contraction and close to prevent blood flowing back into the heart.

Vena cava

The main vein that brings deoxygenated blood from the body into the right atrium.

Pulmonary artery

The artery that carries deoxygenated blood from the right ventricle towards the lungs.

Pulmonary vein

The vein that returns oxygen-rich blood from the lungs to the left atrium.

Aorta

The largest artery in the body which carries oxygenated blood from the left ventricle at high pressure to the rest of the body.

Oxygen debt

An accumulation of deficit when oxygen levels are insufficient for aerobic respiration, requiring extra oxygen post-exercise to break down lactic acid.

Arteries

Thick-walled, muscular blood vessels that carry oxygenated blood (except the pulmonary artery) away from the heart at high pressure.

Veins

Thin-walled blood vessels with a wide lumen and valves that carry deoxygenated blood (except the pulmonary vein) towards the heart at low pressure.

Capillaries

Tiny blood vessels with walls only one cell thick, allowing for the diffusion of substances between blood and tissue cells.

Arterioles

Narrow vessels that connect arteries to capillaries.

Venules

Narrow vessels that connect capillaries to veins.

Renal artery

The blood vessel that carries blood towards the kidney.

Renal vein

The blood vessel that carries blood away from the kidney.

Hepatic artery

The blood vessel that brings oxygenated blood from the heart to the liver.

Hepatic vein

The blood vessel that brings deoxygenated blood from the liver back to the heart.

Hepatic portal vein

The blood vessel that transports deoxygenated blood from the gut to the liver.

Plasma

The liquid component of blood responsible for transporting $CO_2$, nutrients, urea, mineral ions, hormones, and heat energy.

Red blood cells

Concave disc-shaped cells with no nucleus that transport oxygen around the body in the form of oxyhaemoglobin.

Platelets

Cell fragments involved in blood clotting and forming scabs to prevent blood loss and the entry of microorganisms.

Phagocytes

White blood cells with a multi-lobed nucleus and granular cytoplasm that engulf and digest pathogens through phagocytosis.

Lymphocytes

White blood cells with a large round nucleus and clear cytoplasm that produce antibodies and antitoxins to destroy pathogens.

Fibrinogen

A soluble protein in blood plasma that is converted into insoluble fibrin by chemicals released from platelets during clotting.

Fibrin

An insoluble protein that forms a mesh across a wound to trap red blood cells and form a blood clot.