Transport in Mammals

Plasma

Soluble proteins

Fibrinogen

Prothrombin

Antibodies

Help fight diseases

Dissolved mineral salts

Food substances

Glucose

Amino acids

Vitamins

Fats

Excretory products

Urea

Uric acid

Carbon dioxide as hydrogencarbonate ions

Hormones

Insulin

Red Blood Cells

Contain the pigment haemoglobin

Combine reversibly with oxygen

Enable them to transport oxygen from the lungs to all cells in the body

Iron-containing protein

Biconcave in shape

Increase surface area to volume ratio

Thus to allow the cells to absorb and release oxygen at a faster rate

Flattened

Absence of nuclei

Produced by the bone marrow

Lifespan of 3 - 4 months

Destroyed in the spleen

Releasing haemoglobin

Broken down in the liver

Releasing iron which is then stored in the liver

Forming bile pigments

White Blood Cells

Colourless

Absence of haemoglobin

Irregular in shape

Contain nuclei

Mobile

Types

Lymphocytes

Each has a large rounded nucleus

Small amount of non-granular cytoplasm

Produce antibodies which protect that body from diseases

Phagocytes

Each has a lobed nucleus

Granular cytoplasm

Ingest foreign particles such as bacteria

a.k.a. Phagocytosis

Platelets / Thrombocytes

Not true cells

Membrane-bound fragments of cytoplasm from certain bone marrow cells

Involve in clotting of blood

1. Damaged tissues and platelets produce thrombokinase, an active enzyme

2. Prothrombin, an inactive enzyme is then activated by thrombokinase and calcium ions to form thrombin

3. Soluble protein fibrinogen is then converted and catalysed by thrombin to form insoluble fibrin threads

4. Fibrin threads entangle blood cells and the whole mass forms a clot