Increased blood CO₂ levels.

Damage to a blood vessel wall and subsequent exposure to collagen.

Infection in the blood.

Infection in the tissues.

Decreased blood oxygen levels.

Lymphocytes are the largest of all the white blood cells in humans.

Lymphocytes make up about 30% of leucocytes.

Leukaemia is a condition resulting from the uncontrolled production of white blood cells.

Lymphocytes have a single large non-segmented nucleus.

Lymphocytes are derived from committed lymphoid stem cells.

Nitric oxide: inhibits

Prostacyclin: inhibits

Thromboxane A₂: inhibits

Prostacyclin: stimulates

Thromboxane A₂: stimulates

The extrinsic pathway is initiated by the release of factor III from damaged tissue to complex with factor VII and V.

The formation of a platelet plug is inhibited by healthy endothelium through the release of ADP.

Prothrombin is the enzyme that catalyses the conversion of fibrinogen into long fibrin fibres.

The intrinsic pathway is initiated by the activation of factor X.

Thromboxane A₂ is released by damaged vessel walls to initiate vasoconstriction.

If

the supply of iron in the diet falls, stored iron is released from ferritin.

Vitamin

C can increase iron absorption by oxidising ferrous ions to ferric ions.

Only

about 10% of ingested iron is absorbed into the body each day.

Free

iron will bind with apotransferrin to form transferrin, which can then be

transported in the blood.

Damage to the bone marrow.

Inadequate bilirubin levels.

Insufficient Vitamin B₁₂.

Bleeding.

Abnormal haemoglobin.

A

person who is blood group O positive donates to a person who is blood group AB

positive.

A person who is blood group A negative donates to a person who is blood group A

positive.

A person who is blood group AB positive donates to a person who is blood group A

positive.        

A person who is blood group O positive donates to a

person who is blood group B negative.

A person who is blood group B positive donates to a person who is blood group AB positive.

Each of the subunits of the haemoglobin molecule contains a haem group that is necessary for the binding of oxygen.

Haemoglobin is an excellent acid-base buffer because the iron binds bicarbonate.

Haemoglobin from erythrocytes that have been removed from the circulation is degraded into bilirubin and other compounds.

Males have a haemoglobin concentration of around 16 g per 100 ml of whole blood and females around 14 g per 100 ml of whole blood.           

The human erythrocyte contains haemoglobin, a respiratory pigment based on the iron atom.

generally have single large non-segmented nuclei.

are one type of granulocyte.

are derived from committed myeloid cells in the bone marrow.

are chemotaxic.

make up the majority of white blood cells.

the formation of a fibrin clot.

the formation of a blood clot.

vascular spasm.

the formation of a platelet plug.

secretion of histamine.