Keywords- 2

Cardiovascular disease

A condition affecting the heart or blood vessels

Coronary heart disease

Blood vessels supplying the heart are narrowed or blocked

Stroke

Oxygen is cut off to the brain which makes the brain unable to function.

Diffusion

Net movement of particles moving from an area of high concentration to an area of low concentration

Mass transport system

All substances move in the same direction at the same speed.

Mass flow

Liquid or gases moving from an area of high pressure to an area of low pressure.

Arteries

Blood vessels that take blood away from the heart.

Capillaries

A minute thin-walled vessel of the body that forms a network between arterioles & venules.

Arterioles

A very small blood vessel that branches off from your artery & carries blood away from heart to organs & tissues.

Venules

A very small vein, connecting blood from the capillaries to the veins.

Veins

Blood vessel that take blood to the heart.

Single circulation

Blood passes through the heart once in its passage around the body.

Double circulation

Blood passes through the heart twice in its passage around the body.

Polar molecule

One end of a molecule is partially positive whilst the other end of the molecule is partially negative

Dipole

Uneven sharing of electrons between 2 atoms engaging in a covalent bond.

Hydrogen bonding

Interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons.

Hydrophilic

Water-attracting

Hydrophobic

Water-repelling

Cardiac muscle

• Muscle tissue found only in the heart

• Responsible for ability of heart to pump blood.

Collagen

A protein in the body.

Systole

Contract

Diastole

Relax

Coronary arteries

Supplies blood to the heart.

Cardiac cycle

A sequence of alternating contraction and relaxation of the atria & ventricles in order to pump blood throughout the body.

Left & right atria

Heart chambers that receive blood into the heart & drives it into a ventricle.

Ventricles

Heart chambers that receive blood from the atrias & drives blood into pulmonary artery.

Atrial systole

Atrium contracts

Ventricular systole

Ventricles contract

Cardiac diastole

Heart is relaxed

Semilunar valves

Paired valves in the heart between the pulmonary artery & aorta.

Thrombosis

Occurs when blood clots block blood vessels which limits flow of blood.

Heart attack (myocardial infarction)

Occurs when flow of blood that brings oxygen to a part of your heat muscle becomes blocked.

Endothelium

A tissue which forms a single layer of cells lining various organs & cavities of the body e.g. blood vessels.

Inflammatory response

Occurs when tissues are injured by bacteria, trauma etc.

Cholesterol

A waxy, fat-like substance made in the liver which your body needs for good health, but in the right amounts.

Atheroma

A fatty substance that builds up in your arteries over time.

Plaque

A small, abnormal patch of tissue on a body part or organ. This is a build up of substances from a fluid e.g. cholesterol.

Positive feedback

A product of a reaction, leads to an increase in that reaction.

Platelets

Small, colourless cell fragments in the blood that form blood clots which stops or prevents bleeding.

Cascade

A series of enzymic reactions that at each step convert an inactive enzyme into an active enzyme.

Thromboplastin

An enzyme secreted by injured cells e.g. platelets which transforms prothrombin into thrombin.

Prothrombin

A protein produced by the liver which converts into thrombin.

Thrombin

A protease which converts fibrinogen into fibrin.

Fibrinogen

A protein made in the liver which forms fibrin.

Fibrin

A tough protein involved in forming blood clots in the body. Made by fibrinogen.

Angina

A type of chest pain caused by reduced blood flow to the heart.

Anaerobically

Without oxygen.

Ischaemic

An organ is not getting enough blood & oxygen.

Arrhythmia

Irregular heartbeat.

Aneurysm

The enlargement of an artery caused by weakness in the arterial wall.