the circulatory system CHAPTER 1.2 https:www.wickedbiology.wordpress.com

Circulatory system: Transports substances continuously around the entire body Consists of : Cardiovascular system : heart, blood vessels and blood Lymphatic system: lymphatic vessels and lymphoid tissues within the spleen, thymus, tonsils, lymph nodes and lymph Transports nutrients, water & O2 to body cells Remove CO2 and other nitrogenous wastes from body cell Consists of 3 components: Medium Vessels Pump https:www.wickedbiology.wordpress.com

a) medium/fluid Required to carry materials around the circulatory system In human & animals : BLOOD Insects : HAEMOLYPMH Composition of human blood Plasma – 55% Cellular Elements– 45 % https:www.wickedbiology.wordpress.com

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Fibrin and clotting factors Cellular components (45%) Human Blood Plasma (55%) Serum Fibrin and clotting factors Cellular components (45%) Erythrocytes (red blood cells) Leucocytes (white blood cells) Agranulocytes Lymphocytes Monocytes Granulocytes Neutrophils Basophils Eosinophils Thrombocytes (platelets) https:www.wickedbiology.wordpress.com

Cellular components of blood https:www.wickedbiology.wordpress.com

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a) Erythrocytes RED BLOOD CELLS 5 million per mm3 of blood DO NOT HAVE : Nucleus mitochondria ribosomes Full of haemoglobin to bind O2 & CO2 Made in bone marrow live for about 120 days Destroyed & recycled in liver https:www.wickedbiology.wordpress.com

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adaptations HAVE NO NUCLEUS : provide more space for haemoglobin Haemoglobin transports O2 – combined as oxyhaemoglobin – from lungs to the body tissues for respiration Also carry CO2 as hydrogen-carbonate from the respiring tissues to the lungs BICONCAVE DISC- SHAPED CELLS : increase the TSA/V ratio for optimum gaseous exchange SMALL & FLEXIBLE: able to squeeze through narrow capillary walls https:www.wickedbiology.wordpress.com

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b) leucocytes WHITE BLOOD CELLS Colorless No hemoglobin Larger than erythrocytes; fewer in number ≈ 7000 per mm3 of blood No fix shape have nucleus Can change their shapes & squeeze through the walls of capillaries Important in body mechanisms against disease WHITE BLOOD CELLS GRANULOCYTES AGRANULOCYTES https:www.wickedbiology.wordpress.com

a) Granulocytes Have : Capable of amoeboid movement granular cytoplasm lobed nucleus Capable of amoeboid movement engulf bacteria by phagocytosis Produced in bone marrow GRANULOCYTES BASOPHIL NEUTROPHIL EOSINOPHIL https:www.wickedbiology.wordpress.com

BASOPHIL NEUTROPHIL EOSINOPHIL RAREST -1% of total leucocytes NEUTROPHIL MOST COMMON - Engulf bacteria by phagocytosis EOSINOPHIL Detoxify chemicals & reduce inflammation https:www.wickedbiology.wordpress.com

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Phagocytosis by granulocyte https:www.wickedbiology.wordpress.com

b) Agranulocytes Have non-granular cytoplasm and a compact nucleus MONOCYTES LYMPHOCYTES Have non-granular cytoplasm and a compact nucleus https:www.wickedbiology.wordpress.com

a) Monocytes The largest of the five types of white blood cell Produce in bone marrow Have bean-shaped nucleus Ingest bacteria by phagocytosis https:www.wickedbiology.wordpress.com

b) Lymphocytes has large rounded nucleus contains many genes : efficient antibody protein productions Produced in the lymph glands & the lymphatic nodes FUNCTIONS: Produce antibodies specific defense against toxins produced by bacteria and infecting germs https:www.wickedbiology.wordpress.com

(c) Thrombocytes a.k.a PLATELETS Not a cells tiny fragments of other cells (megakaryocytes) Colorless, irregular shape, without nucleus Made in bone marrow last about 6-7 days https:www.wickedbiology.wordpress.com

(c) Thrombocytes FUNCTIONS: Have amoeboid movements Important in blood clotting & repairing damages tissues Help to maintain the integrity of blood vessel wall https:www.wickedbiology.wordpress.com

Blood plasma https:www.wickedbiology.wordpress.com

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Plasma Yellowish liquid Serum : blood plasma with its clotting factors (such as fibrin) removed 90% water, 10% dissolved substances https:www.wickedbiology.wordpress.com

Plasma consist of : Heat produced by respiration absorbed by plasma dissolved gases, absorbed food molecules, excretory waste products, hormones & salts Heat produced by respiration absorbed by plasma https:www.wickedbiology.wordpress.com

b) Functions of blood Transport O2 & CO2 Transport absorbed food materials Transport of excretory waste products Deamination excess amino acids occur in _______? Transport heat Blood distribute heat from heat-producing sites (e.g. skeletal muscles) to areas of heat loss (e.g. skin) Transport of hormones Transport of water to tissues b) Functions of blood https:www.wickedbiology.wordpress.com

hAEMOLYMPH https:www.wickedbiology.wordpress.com

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c) Function of Haemolymph in Transport the circulatory fluid in body cavities of insects A.K.A ‘ insect blood’ Flows freely within the body cavity makes direct contact with all the internal tissues & organ of insects Contains water, amino acids, sugar, salts & white cell https:www.wickedbiology.wordpress.com

c) Function of Haemolymph in Transport the circulatory fluid in body cavities of insects Transport hormones, nutrients, salt & metabolic wastes around the body Does not contain haemoglobin or RBC Does not transport O2 and CO2 https:www.wickedbiology.wordpress.com

The Structure of Human Blood Vessels https:www.wickedbiology.wordpress.com

Tubes for the medium to flow through Heart is connected to a series of tubes called blood vessels BLOOD VESSELS: Tubes for the medium to flow through Main types of vessels: artery, arteriole, capillary, venule and vein Each type of blood vessel has a different structure according to their function` https:www.wickedbiology.wordpress.com

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Aspect Artery Capillary Vein Vessels Structure of wall Three layers – endothelium, smooth muscle & fibrous connective tissue Single layer - endothelium Thickness of wall Thick Very thin – single cell Thinner than arteries Relative diameter of lumen Narrow Very narrow – about the size of single erythrocyte Wide Direction of blood flow Away from the heart From arteries to vein Towards the hearts Valve Absent Present Oxygen transported Carries oxygenated blood (except pulmonary artery) Arteriole carries oxygenated blood Venule carries deoxgenated blood Carries deoxygenated blood (except pulmonary vein) Relative blood pressure High Gradually decreases from the arteriole end to the venule end Lowest Vessels https:www.wickedbiology.wordpress.com

The circulatory systems in humans and other animals https:www.wickedbiology.wordpress.com

Open circulatory system Insects, crustaceans & mollusks Heart pumps haemolymph through the aorta which branches into number of arteries that open into body cavity https:www.wickedbiology.wordpress.com

Open circulatory system Haemolymph reaches the body cells directly diffuses between body cells & re- enters the heart through open-ended veins https:www.wickedbiology.wordpress.com

Closed circulatory system Found in all vertebrates & some invert (e.g. earthworms) Heart pumps blood rapidly through & within completely closed continuous system of vessel https:www.wickedbiology.wordpress.com

Closed circulatory system never comes in direct contact with body cells https:www.wickedbiology.wordpress.com

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