Biology Notes

What are white blood cells or leukocytes? They are colorless and they are the mobile units of bodies protective system, they have defensive action. They have nucleus, short life span, large in size and have defensive action. Your blood is formed from red blood cells, white blood cells, platelets, and plasma. Your white blood cells account for less than about 1% of your blood , but their impact is big. White blood cells also are called leukocytes. They protect you against illness and disease. Think that white blood cells as your immunity cells. during a sense, they're always at war. They flow in the bloodstream to fight against viruses, bacteria, and other foreign invaders . When your body is in distress and a specific area is under fire , white blood cells rush in to assist destroy the harmful substance and stop illness. White blood cells are created in the bone marrow. they're stored in your blood and lymph tissues. Because some white blood

What are platelets Platelets  are  small  blood cells that  facilitate  your body  to  clots  to prevent   injury . If  one amongst  your blood vessels gets  broken , it sends out signals to the platelets. The platelets then rush to  the positioning   of harm . they  form  a plug (clot)  to repair  the  injury . The process of spreading across the surface of a  broken   vessel   to prevent   injury   is named  adhesion.  this can be   as a result of   once  platelets get to  the positioning  of the injury, they grow sticky tentacles that  facilitate  them stick (adhere)  to at least one  another. They  conjointly   send  chemical signals  to draw in   a lot of  platelets.  the extra  platelets pile onto the clot  during a   method   known as  aggregation. Facts  regarding  platelets Platelets  area unit   created  in your bone marrow  together with  your white and red blood cells. Your bone marrow  is that the  spongy center  within  your bones. Another name for platel

Osmoconformers: Animals which have body fluid concentration equal to the concentration of solution in the external environment are called osmoconformer. These animals have their body fluid isotonic. They do not gain or loss the water. Just Because of the body fluid and external solution are equally concentrated. Hence equal amount of water move in and out the body. Examples: Ray, Hag fish, shark, invertebrates. Osmoregualtors:  Animals which have body fluid concentration different from outside environment are called osmoregualtors. They need energy to keep balance of water and salt in th body.  They remove extra water in fresh water environment and remove salt in marine environment.

Haemoglobin About 95  percentage  of the dry weight of the  purple  blood  cellular   includes  hemoglobin, the substance  important  for oxygen transport. Hemoglobin is a protein; a molecule  includes   4  polypeptide chains (a tetramer),  every  chain consisting of  extra  than  140  amino acids. To  every  chain  is connected  a chemical  structure   referred to as  a heme group. Heme  is composed  of a ringlike  natural  compound  called  a porphyrin, to which an iron atom  is attached . It is the iron atom that reversibly binds oxygen  because the  blood travels  among  the lungs and the tissues. There are  4  iron atoms in  each  molecule of hemoglobin, which, accordingly, can bind  4  atoms of oxygen. The  complex  porphyrin and protein  shape   gives  the  right   environment  for the iron atom  in order that  it binds and releases oxygen appropriately  underneath  physiological  situations . The affinity of hemoglobin for oxygen is so  remarkable  that  on the  oxy

Introduction of blood Blood (Introduction and Composition) Definition : Blood is specialized connective tissue consisting of liquid intercellular substance plasma and formed element RBCs , WBC, and platelets.  It circulate in closed system of blood vessels and provides a medium to transport substances from one part of the body to the other. pH of blood 7.4 Range 7.35 to 7.45 Limits Not lower than 6.8 and not more than 7.8 pH of RBC 7.1 (less alkaline)  composition of  blood.  I) formed element: 45%  cellular part RBC , WBC, and platelets. II) plasma (fluid part) 55%:  1) water 91 to 92% 2) solids= 8 to 9% a) in-organic: sodium, magnesium, potassium, phosphorus, copper and iron b) organic i) proteins serum albumin 4.5% serum globulin 2.5%  fibrinogen 0.3% prothrombin, etc ii) Non protein:  nitrogenous substances, eg urea, uric acid, creatinine, NH3 and amino acids etc iii) fats neutral fat, phospholipid, cholesterol, etc   iv) carbohydrates:   gluco

Blood plasma:  plasma is that part of extracellular fluid which is identical to interstitial fluid but it contains 7% proteins while interstitial fluid contains 2% proteins. Volume 3300 ml Difference between plasma and interstitial fluid:  both plasma and interstitial fluid are part of extracellular fluid and are almost identical to each other except for Plasma contains 7% proteins while interstitial fluid contains 2% proteins. Difference between serum and plasma: Fuid part of blood which expresses out after clotting due to clot retraction, is called serum. serum resembles plasma but it has no fibrinogen and other clotting factor as it is formed after clotting.  Difference between human and animal blood:  Human blood forms hemin crystals, while animals blood do not.  Origin of Plasma proteins:  all plasma proteins are formed in liver except Gamma globulin which is formed in reticuloendothelial system, plasma cells, and lymphocytes.  Function of Plasma prot

Red Blood Cells RBCs are most abundant cells in blood . Each cubic mili meter of male blood has about 5-5.5 million red blood cells, while female has 4-4.5 millions RBCs. They contain a respiratory pigment hemoglobin which transport oxygen from lungs to tissue and CO2 frombtissue to lung. RBcs are formed in red bone marrow of small bones vertebrae, sternum and ribs, but they are formed in Liver and spleen during early embryonic development. During formation they have nucleus but when they mature they lose their nucleus and inter into circulatory system.

Function of blood  1.respiratory function  blood transports oxygen from lungs to tissue and carbon dioxide from tissue to lungs. 2. nutritive function:  transports food absorbed from gut and mobilized from storage depots to tissue. 3. Excretory function  it transports excretory metabolite end products from tissue to organs of excretion for example Kidneys, lungs, intestine, and skin etc 4. carrier function:  it carries hormones, enzymes, antibodies and vitamins, inorganic and organic salts and other essential chemicals to their place of activity. 5) defensive action:  a) neutrophil and macrophages phagocytize bacteria. b) antibodies combat disease causing organisms. 6) Hemostatic functions: It contains clotting factors, so it prevents hemorrhage by coagulation. 7) Regulatory function  Blood regulates: i) water balance ii) acid base balance or blood PH iii) Ion balance iv) body temperature v) blood pressure vi) blood volume vii) blood viscosity viii) osmotic pr