Blood
Blood, heart and blood vessels together make up the cardiovascular system.
Blood can also be classified as part of circulatory system.
Blood is classified as a type of Connective tissue because most blood cells come from bone, which is type of Connective tissue.
Blood contains-
1. Cellular elements called formed elements (45%)
2. A fluid mattix called plasma (55%)
Both the formed elements and plasma play important roles in homeostasis.
Function of blood
Blood is primary transport medium that perform vital pick up and delivery services for the body. Red liquid that circulate in arteries and veins of body carrying oxygen to and carbon dioxide from tissue of the body.
1. Transportation
2. Maintenance and regulation
3. Protection
1. Transportation
1. Respiratory
1. Blood transport O2 from lungs to body tissue.
2. Blood transport CO2 from body tissue to lung.
2. Nutrition
Blood transport nutrients from alimentary canal.
3. Hormones
Blood transports hormones from endocrine gland to their target glands and tissues.
4. Excretory
It transport waste product from tissue to ( excretory organ) to kidney
Example; urea,.uric acid, water
It transport heat produced in the body parts.
Vitamin D produce in skin and transported by blood into liver, then kidney for processing active vitamin D.
Active vitamin D transported in blood to small intestines, where it prevent calcium loss from kidney.
2. Maintenance.and Regulation
1. Perform Haemostasis
Blood regulates acid base balance (PH) through distribution of buffers.
Water and electrolytes
It regulates amount of water and electrolytes in body fluids. (Na, Ca, K, Cl, P, Mg)
2. Regulate body temperature
It regulates body temperature mainly by increasing or decreasing the blood flow to the skin.
Blood is the key stones of body's heat regulating mechanism.
3. Protection
1. Collecting mechanism
Blood collecting mechanism protects against blood loss.
Cells and chemicals of blood constitute important part of immune system protecting against foreign substance.
Phagocytic WBC
Antibodies
Interferon and complement protect against foreign microbes and toxins.
Properties of Blood
1. Amount
Blood constituents about 7-9% of all body weight or 97ml/kg of body weight
Average man; 5-6 liter of blood
Average female; 4-5 liter of blood
Normal range of haemoglobin in man; 13.8- 17.2 grams per deciliter (g/dl)
in female; 12.1 to 15.1 grams per deciliter
2. Viscosity (thickness)
Blood viscosity is measurement of thickness and stickiness of individual blood.
A blood contain RBC (erythrocytes) which constituent to thickness of blood.
Increased blood viscosity can caused by increase in RBCs and also cause slower the flow.
3.Specific gravity
Specific gravity or density of blood is between 1.045 and 1.065 compared with 1.000 for water.
4. Colour
Red colour of arterial blood is due to oxygenated haemoglobin.
When O2 is removed,the blood appear bluish and dark WBCs and platelets in blood are clear and plasma is yellowish.
5.pH
Blood is slightly alkaline with pH that usually ranges between 7.35 -7.45
Arterial blood is more alkaline than venous blood because it has less O2.
5. Temperature
Temperature of blood averages about 100.4 °F which us slightly higher than normal body temperature.
7. Salinity
The salt concentration of blood is about 0.85% Nacl.
Components of Blood
In Body
1. Blood 8%
2. Body fluids 92%
Blood
Blood 8%
1. Plasma 55%
2. Formed element 45%
Plasma 55%
Water (91.5%), Protein (7%) , Other Solutes (1.5%)
Protein 7%
Fibrinogen 7%, Albumin 54%, Globulin 38%
Other Solutes (1.5%)
1. Electrolytes
2. Nutrients
3. Gases
4. Waste products
5. Regulatory substances, enzyme, Hormones
2. Formed Elements
Formed elements 45%
1. Red blood cells (Erythrocyte) number (4.8-5.4 million/mm3)
2. Platelet (Thrombocytes) 2.50000-4,00000/mm3
3. White blood cell (Leucocytes) 4000-11000/mm3
1. Neutrophil (60-70% of WBC)
2. Basophil 0.5-1%
3. Monocytes 3-8%
4. Lymphocyte 20-25%
5. Eosinophil 2-4%
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