1B.2 - Functions of the blood

Cardiovascular system

The mass transport system of the body made up of a series of vessels with a pump (the heart) to move blood through the vessels

Circulation

The passage of blood through the blood vessles

Active transport

The movement of substances into or out of the cell using ATP produced during cellular respiration

Buffer

A solution which resists changes in pH

Leukocytes

White blood cells - There are several different types which play different important roles in defending the body against the entry of pathogens and in the immune system

Platelets

Cell fragments involved in the clotting mechanism of the blood

Megakaryocytes

Large cells that are found in the bone marrow and produce platelets

Oxyhaemoglobin

The molecule formed when oxygen binds to haemoglobin

Carbaminohaemoglobin

The molecule formed when carbon dioxide combines with haemoglobin

Carbonic anhydrase

The enzyme that controls the rate if the reaction between carbon dioxide and water to produce carbonic acid

Bohr effect

The name given to changes in the oxygen dissociation curve of haemoglobin that occur due to a rise in carbon dioxide levels and a reduction of the affinity of haemoglobin for oxygen

Fetal haemoglobin

A form of haemoglobin found only in the developing fetus

• Has a higher affinity for oxygen than adult haemoglobin

Seritonin

A chemical that causes the smooth muscle of the blood vessels to contract - This narrows them which cuts off the blood flow to the damaged area

Thrompboplastin

An enzyme which activates/catalyses the protein prothrombin. This starts the chain of biological reactions which leads to the formation of blood clots

Thrombin

An enzyme which acts on Fibrinogen, converting it to fibrin during clot formation

• Soluble

• Active

Precursor

A biologically inactive molecule which can be converted into a closely related biologically active molecule when needed

Fibrinogen

A plasma protein which is the precursor of the protein Fibrin

• Soluble

• Active

Fibrin

A protein formed from fibrinogen by the action of thrombin that forms a mesh of fibres that trap erythrocytes and platelets to form a blood clot

• Insoluble

• Active