1.2 - THE CIRCULATORY

SYSTEM

1.2 - THE CIRCULATORY

SYSTEM

                                        

                                        

                                                 

                                        

                                        

                                                 

LEARNING OUTCOMESLEARNING

OUTCOMES• To state what a circulatory system is,

• To state the three components of circulatory system in humans

& animals• To state the medium of

transport humans & animals• To state the composition of

human blood• Explain the function of blood &

haemolymph in transport

                                        

                                        

                                                 

CIRCULATORY SYSTEM

CIRCULATORY SYSTEM• The mass flow of fluid through the

tissues & organ of the organism.• The bodily system consisting of the heart,

blood vessels, and blood that circulates blood throughout the body, delivers

nutrients and other essential materials to cells, and removes waste products

• Allows for the transport & exchange of nutrients, oxygen & waste products.

• Also protecting the body against infection.• 3 main components : a medium

(blood), vessels (arteries, capillaries & veins) & a pump (heart).

                                        

                                        

                                                 

Blood & Haemolymph

Blood & Haemolymph

• Blood – medium of transport in human & animals

• Transport O2, CO2, nutrients, hormones & waste products.

• Regulate the pH of body fluid, the body temperature & the water content

of cells.• Protects the body against diseases,

blood clots to protect the body against excessive blood loss following an

injury.

                                        

                                        

                                                 

•Haemolymph – in many arthropods (such as insects) and

certain molluscs, fills in the entire body cavity (haemocoel).

• A circulating blood-like fluid with an open circulatory system

• Transport water, inorganic salts & organic compounds

• The haemolymph bathes the tissues & internal organ directly.

                                        

                                        

                                                 

COMPOSITION OF HUMAN

BLOOD

COMPOSITION OF HUMAN

BLOODHUMAN BLOOD

BLOOD CELLS (45%)

PLASMA (55%)

PLATELETS• 2.5 mil/mm3

LEUCOCYTES• 7000 mil/mm3

ERYTHROCYTES• 5 mil/mm3 FIBRINOGEN SERUM

Granulocyte :-• Basophils• Neutrophils• Eosinophils

Agranulocytes :-• Monocytes

• Lymphocytes

                                        

                                        

                                                 

2 main components of human blood

55% plasma 45% blood cells

1. Pale yellow liquid

2. 90% of water 10% of a variety of dissolved substances

> nutrient > mineral ions > antibodies > enzymes > hormones

1. Red blood cells

2. White blood cells

3. platelets

                                        

                                        

                                                 

•Contain 5 million RBC in every millilitre of human blood

•Erythrocytes is shaped like a biconcave disc (thinner at the centre than at its edge) large TSA/V ratio for gaseous exchange

•7.5-8.0 µm in diameter•Has a thin plasma membrane•Small biconcave shape + thin flexible plasma membrane enable the RBC to squeeze through the narrow blood capillaries.

                                        

                                        

                                                 

• Mature RBC have no nucleus more space to pack in haemoglobin (respiratory protein containing iron).

• Haemoglobin contains haem groups which gives the erythrocytes its red colour.

• The haem group contains an iron atom & is the site of O2 binding.

                                        

                                        

                                                 

• Each blood cells contains about 250 million haemoglobin molecules. Each haemoglobin can combine with 4 O2

molecules oxyhaemoglobin• Lifespan of an erythrocytes is only 120 days destroyed by the phagocytes in

the liver & spleen.• Continuously produced by the bone

marrow of the long bones, ribs, skull & vertebrae.

• More than 2 million RBC are destroyed & replaced every second in the human

body.

                                        

                                        

                                                 

Colourless & have a nucleus, not contain haemoglobinLarger than RBCClassified as either granular or granular6000 – 10000 WBC in every millilitre of blood.Do not have fix shape, can move by changing body shapeProduced in the bone marrow, some migrate to the thymus gland & others to lymph nodes during their growth & development stages.

                                        

                                        

                                                 

LEUCOCYTESLEUCOCYTES

Granulocytes

Have granular cytoplasm & a lobed nucleus

• produced in bone marrow

• 72% leukocytes are granulocytes

Basophils : Secrete heparin to prevent blood clotting

Eosinophils : Help to control allergic responses

Neutrophils : Phagocytes granulocytes. They engulf foreign

material (bacteria) by phagocytosis & destroy them.

Agranulocytes

• relatively clear

cytoplasm & nucleus is not

lobed.

Monocytes : The largest of the leucocytes. Circulate in the

bloodstream for a few days body tissues to become phagocytic

macrophage

Lymphocytes : The smallest leucocytes. Important in the body’s

defence against pathogens. Some produce antibodies to aid in the

destruction of pathogens or neutralise the toxins

                                        

                                        

                                                 

                                        

                                        

                                                 

•Small irregular shaped cell fragments produced in the bone

marrow•Play an important role in

blood clotting to reduce blood loss & to prevent the entry of

pathogens through the wounds into the body.

•Each millilitre of blood contains about 250000 platelets., do not

have a nucleus.

                                        

                                        

                                                 

• The pale yellow liquid part of the blood

CONTENT DESCRIPTIONWater •90% of plasma content.Plasma protein

• Albumin•Globulin – type of antibody

•Fibrinogen- helps blood clotting Mineral ions • sodium, potassium & chloride

Absorbed food

substances

• glucose, amino acids, cholesterol & other lipids

Waste products

Urea, CO2, uric acid, creatinine and a little ammonium ion.

Dissolved gases

O2, CO2 & Nitrogen

Hormones & enzymes

Insulin, adrenaline, ADH

                                        

                                        

                                                 

• Blood serum – plasma from which fibrinogen & other clotting

factors have been removed

                                        

                                        

                                                 

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