Transport in Mammals

Vocabulary flashcards reviewing transport in mammals, blood composition, heart structure, circulation pathways, and related cardiovascular conditions.

Plasma

The liquid component of blood making up $55\%$ of total blood volume, consisting of $90\%$ water and $10\%$ dissolved substances including proteins, minerals, nutrients, excretory products, and hormones.

Red Blood Cells (RBC)

Circular, flattened, biconcave disc-shaped blood cells with a diameter of $7\,\mu m$ that lack a nucleus and mitochondria, containing the red pigment haemoglobin for oxygen transport.

Haemoglobin

An iron-containing red protein pigment present in red blood cells that reversibly binds to oxygen in the lungs to form oxyhaemoglobin.

Phagocytes

White blood cells produced in the bone marrow that feature a lobed nucleus and granular cytoplasm, which function by engulfing and digesting foreign particles like bacteria.

Lymphocytes

White blood cells produced in lymph glands/nodes that contain a large rounded nucleus and non-granular cytoplasm, responsible for producing antibodies against pathogens.

Phagocytosis

The process by which phagocytes engulf foreign particles such as bacteria by flowing over them, enclosing them, and digesting them inside their cytoplasm.

Thrombokinase

An enzyme released by damaged tissues and platelets that converts inactive prothrombin into active thrombin in the presence of calcium ions during blood clotting.

Fibrin

An insoluble protein formed from soluble fibrinogen by thrombin during blood clotting, forming threads that weave a mesh to trap blood cells and form a clot.

Haemophilia

A genetic condition in which the blood clotting mechanism is impaired, causing affected individuals to be at risk of dying from uncontrollable internal or external bleeding.

Blood Group O

The universal donor blood type characterized by having no antigens on red blood cells and containing both antibody a and antibody b in serum.

Transplant Rejection

An immune response where recipient lymphocytes produce antibodies to destroy a transplanted organ or tissue recognized as foreign body.

Arteries

Thick-walled, muscular, and elastic blood vessels that carry high-pressure blood away from the heart to tissues throughout the body.

Veins

Thin-walled blood vessels containing internal semilunar valves that carry low-pressure blood back toward the heart.

Capillaries

Microscopic, single-cell-thick blood vessels positioned between arterioles and venules that provide a large surface area for exchange of materials between blood and tissue fluid.

Pericardium

A two-layered fluid-filled sac surrounding the heart that contains pericardial fluid to reduce friction during heartbeat movements.

Septum

A central muscular wall dividing the heart into left and right sides, preventing the mixing of oxygenated and deoxygenated blood.

Pulmonary Circulation

The system of blood circulation that transports deoxygenated blood from the heart to the lungs and returns oxygenated blood back to the heart.

Systemic Circulation

The system of blood circulation that pumps oxygenated blood from the left side of the heart to tissues around the whole body and collects deoxygenated blood back to the heart.

Systole

The contraction phase of the cardiac cycle in which the atrioventricular valves close and semilunar valves open to force blood out of the heart chambers.

Diastole

The relaxation phase of the cardiac cycle in which atrioventricular valves open and semilunar valves close, allowing blood to refill the heart chambers.

Pulse

A wave of dilation and recoil passing along arteries created by sudden increases in pressure following each ventricular contraction of the heart.

Tissue Fluid

A colourless fluid filling spaces between tissue cells, formed when blood plasma without large proteins is forced out through capillary walls.

Lymph

A fluid collected inside lymphatic vessels that originates from excess tissue fluid and white blood cells that have moved out of capillaries.

Coronary Arteries

Arteries branching directly from the aorta that lie on the outer surface of the heart and supply heart tissue muscles with glucose and oxygen.

Atherosclerosis

A condition characterized by the deposition of fatty material like cholesterol and saturated fats on the inner walls of coronary arteries, narrowing the lumen and restricting blood flow.

Thrombus

A blood clot formed within a blood vessel that obstructs the flow of blood through the circulatory system.

Electrocardiograph (ECG)

A medical device and recorded trace of the electrical activity of the heart measured over time using electrodes attached to the body.