composition of blood

erythrocytes [120 days]

transports oxygen and carbon dioixde

• formed by erythropoises [red marrow of long bones]
• haemoglobin

oxyhaemoglobin [unstable]

carbaminohaemoglobin [unstable]

carboxyhaemoglobin [stable, CO]

shape

• spongy biconcave disk
• small [pass through capillaries]
• absence of nucleus and ER [increase SA]
• absence of mitochondria [ensures that the oxygen is not used in the cell itself]
• abnormal increase - polycthemia
• abnormal decrease- erythropenia

thrombocytes

• do not have nuclei as they are fragments of cells.

blood clotting

vitamin k & Ca are required for all phases.

platelets release thromboplastin

prothombin [thromboplastin] —> thrombin

fibrinogen [thrombin] —> fibrin

fibrin + corpuscles —> clot

• stops bleeding
• prevents the entry of disease
• anticuagolants like heparin prevents formation of fibrinogen
• in blood banks sodium citrate is added to lock the ca and prevent stored blood from clotting

plasma

straw coloured liquid which consists of enzymes

• water acts as a solvent for nutrients like amino acids, fatty acids, etc.

leucocytes

granulocyte

1. eosinophil

antitoxins

1. neutrophil

antitoxins

1. basophil

phagocytosis

agranulocyte

1. lymphocyte

production of antibodies

1. monocyte

phagocytosis

movements of leucoctes

1. amoeboid movement- movement performed by the pseudopodia.
2. diapedisis - ability to pass through capilary walls and squeeze out in a single line
3. phagocytosis- engulfing and digestion of foreign particles

phagocytosis, antibodies & antitoxins

• formed by leucopoiesis
• abnormal increase- leucocytosis
• abnormal decrease- leucopenia

pus- composed of dead WBC and tissue cells

antibody- antigen response

antigens- chemical substances which stimulate the production of antibodies

antibody- inactivate the antigens

blood grouping & transfusion

blood group- a group of people having similar antigen on its RBC is said to belong to the same blood group

transfusion- the action of transferring blood from one person to another

for a successful transfusion to take the place the antibodies of the receptor must accept the antigens of the donor AS ITS OWN!

• surfaces of RBC contain the antigen [agglutinogens/corpuslar factor]
• plasma has the antibody [agglutinins/plasma facor]

rhesus factor- substance present in the RBC of most people, such people are said to be Rh +

the human heart

external view

shaped like a blunt cone

located centrally between the lungs 2/3 of the mass towards the left side.

held in position by the pericardium

between the two layers pericardial fluid

• three layers of the heart are the epicardium, myocardium and endocardium
• sinoatrial node [pacemaker] - upper wall of right atrium

regulates the contraction and expansion of the heart

blood flow through the heart

cardiac cycle- the series of events which occur during a complete heart beat