Anatomy Week 5 Notes - Blood PDF

Week 5: Blood ============= - Functions of Blood 1. Transport: Oxygen, nutrients, waste, carbon dioxide and hormones 2. Defense against invasion by pathogens: - Phagocytes engulf microbes, others produce antibodies -- Proteins that binds to a pathogen to stop its action and mark it for...

Week 5: Blood ============= - Functions of Blood 1. Transport: Oxygen, nutrients, waste, carbon dioxide and hormones 2. Defense against invasion by pathogens: - Phagocytes engulf microbes, others produce antibodies -- Proteins that binds to a pathogen to stop its action and mark it for destruction by white blood cells - Protects by clotting to prevent fluid floss 3. Regulation - Transports body temperature Picks up heat and transports the heat around the body - When body temperature rises Blood is transported to the dilated vessels in the skin and heat removed to the outer environment. - Proteins dissolved in the plasma Maintains osmotic pressure and regulate body's water salt balance - Buffers in blood Regulate body's acid base balance, keeps it as pH of 7.4 - Formed elements are produced in the red bone marrow which contains stem cells: - Stem cells are parent cells They divide and produces all the blood cell types in the body - Blood Plasma +-----------------------------------+-----------------------------------+ | Water (91%) | | +===================================+===================================+ | Proteins (7%) | Liver produces Plasma Proteins | | | | | | a. Albumins | | | | | | - Contributes to osmotic | | | pressure | | | | | | - Combine with and help | | | transport molecules in the | | | blood | | | | | | b. Globulins | | | | | | - Alpha & Beta Transport | | | substances in blood | | | | | | - Gamma Antibodies produced by | | | lymphocytes to fight | | | pathogens | | | | | | c. Fibrinogen | | | | | | - Inactive plasma protein Forms | | | blood clot when activated | | | | | | Functions: | | | | | | 1. Acts as a Buffer Keeps blood | | | at pH 7.4 | | | | | | 2. Creates osmotic pressure | | | Creates osmotic gradient | | | between blood and | | | interstitial fluid | +-----------------------------------+-----------------------------------+ | Solutes (2%) | Ions, nutrients, waste products, | | | gases, hormones, vitamins | | | | | | - Salts Maintains osmotic | | | pressure and blood pH | +-----------------------------------+-----------------------------------+ - Red Blood cells (Erythrocytes) +-----------------------------------+-----------------------------------+ | Structure | Function | +===================================+===================================+ | 1. Biconcave disks | - Transports oxygen to various | | | tissues of the body in the | | - Biconcave shape increases | hemoglobin | | surface area of diffusion of | | | gases | (Oxygen is poorly soluble in | | | plasma) | | 2. Small | | | | Hb bound to oxygen Oxyhemoglobin | | - Allows movement inside narrow | | | capillaries | Oxygen leaves Hb Deoxyhemoglobin | | | | | 3. Lack organelles | - Hemoglobin: | | | | | - Has greater capacity to carry | Responsible for red color | | oxygen | | | | a. Globin portion (Protein) made | | | up of four separate subunits | | | | | | b. Each subunit has one molecule | | | of heme | | | | | | c. The core of heme has an iron | | | atom | | | | | | d. Iron atom binds to oxygen | | | molecule | | | | | | - Short lifespan | | | | | | | | | | | | - Lacks a nucleus Unable to | | | replenish important proteins | | | and repair cellular damage | | |  | +-----------------------------------+-----------------------------------+ - Destruction of Red Blood cells - Hemoglobin is released into: +-----------------------------------+-----------------------------------+ | Globin | Broken down to amino acids and | | | recycled. | +===================================+===================================+ | Iron | a. Small amount is excreted | | | | | | b. Most of iron is returned to | | | bone marrow | +-----------------------------------+-----------------------------------+ | Heme | Broken down chemically and | | | excreted by liver and kidneys | +-----------------------------------+-----------------------------------+ - When RBCs age, they are phagocytosed by macrophages in liver and spleen a. When RBCs are destroyed, oxygen delivered to cells will decrease Therefore, they must be replaced. b. Kidneys produces erythropoietin (Hormone) When oxygen levels are low c. It stimulates bone marrow to produce more RBCs - Platelets (Thrombocytes) - Not true cells They are fragmentation of large cels (Megakaryocytes) in the red bone marrow +-----------------------------------+-----------------------------------+ | Formation | Function | +===================================+===================================+ | - Formed in the bone marrow | - Blood clotting (Coagulation) | | | | | - Single type of stem cell | | | develops into large cell | | | Megakaryocytes | | | | | | - Cell fragments of | | | Megakaryocytes Platelets | | +-----------------------------------+-----------------------------------+ +-----------------------------------+-----------------------------------+ | 4. Blood Vessel is punctured | Membranes of endothelial cells | | | release substances which causes | | | smooth muscles of the vessel to | | | constrict | | | | | |  | +===================================+===================================+ | 1. Platelets congregate, attach | Platelets secrete chemicals: | | to the broken vessel walls | | | and form a plug | a. Attract more platelets to the | | | area | | | | | | b. Constrict blood vessels | +-----------------------------------+-----------------------------------+ | 2. Platelets and damaged tissue | a. Initiates a cascade enzymatic | | cells release prothrombin | reaction | | activator | | | | b. Prothrombin activator | | | converts prothrombin into | | | thrombin | | | | | | c. Thrombin severs two amino | | | acids chains from fibrinogen | | | | | | d. The | | | activated fragments form | | | fibrin threads | +-----------------------------------+-----------------------------------+ | 3. Fibrin threads form and trap | Blood is transformed from liquid | | red blood cells | to solid gel | +-----------------------------------+-----------------------------------+ - How do platelets clot blood? - Wound Healing - Clot formation prevents blood loss Facilitates repair of damaged blood vessels and tissues by other cells such as fibroblasts - Fibroblasts: Found in connective tissues outside blood vessels - As repair of damaged area proceeds: a. Enzyme (Plasmin) is activated to digest fibrin strands b. Clot eventually dissolves c. Tissue cells can then grow - Homeostasis: CVS interaction with body systems +-----------------------------------+-----------------------------------+ | Lymphatic system | a. Interstitial fluid comes from | | | blood plasma | | | | | | b. Absorbed by lymphatic | | | capillaries, becomes lymph | | | | | | c. Lymph is returned to CVS via | | | Lymphatic vessels | +===================================+===================================+ | Respiratory system | - CVS delivers oxygen from | | | lungs to the rest of the body | +-----------------------------------+-----------------------------------+ | Digestive system | a. CVS delivers nutrients from | | | digestive system to | | | interstitial fluid | | | surrounding cells | | | | | | b. Removes metabolic wastes by | | | delivering waste to excretory | | | organs | +-----------------------------------+-----------------------------------+ | Muscular system | - Contribute blood movement | | | | | | a. Cardiac muscle contractions | | | Circulates blood throughout | | | the body | | | | | | b. Smooth muscle | | | contraction/relaxation | | | changes vessel diameter | | | maintains correct blood | | | pressure | | | | | | c. Skeletal muscle contraction | | | Compresses CVS and Lymphatic | | | vessels | | | | | | - Lymph returns to | | | cardiovascular veins | | | | | | - Blood in cardiovascular veins | | | goes back to the heart | +-----------------------------------+-----------------------------------+ | Skeletal system | a. Red bone marrow produces | | | blood cells | | | | | | b. Bones produces calcium ions | | | for blood clotting | +-----------------------------------+-----------------------------------+ | Endocrine system | - Hormones regulate | | | | | | a. Blood cell production | | | | | | b. Bone calcium release | +-----------------------------------+-----------------------------------+ | Urinary system | a. Kidneys Regulates acid-base | | | and water-salt balances of | | | blood and interstitial fluid | | | | | | b. Erythropoietin (Hormone -- | | | Produced by kidneys) | | | Stimulates red blood cell | | | production | +-----------------------------------+-----------------------------------+ - Human blood types Antigen A foreign substance, a polysaccharide or protein that stimulates an immune response ------------------- ------------------------------------------------------------------------------------- Antibody A protein made in response to an antigen which binds specifically to that antigen Blood transfusion The transfer of blood from one individual to another individual - Blood type is determined by Presence or absence of antigens - Three types of antigens: a. Type A b. Type B c. Rh factor - Blood group types +-----------------------+-----------------------+-----------------------+ | Blood Group types | Antigen A/B Present? | Antibodies A/B | | | | Present? | +=======================+=======================+=======================+ | Blood | | | | Group O | | | | | | | | (Universal donor) | | | +-----------------------+-----------------------+-----------------------+ | Blood Group A | A present, B not | Anti-B present | | | present | | +-----------------------+-----------------------+-----------------------+ | Blood group B | B present, A not | Anti-A present | | | present | | |  | | | +-----------------------+-----------------------+-----------------------+ | Blood group AB | A and B present | Anti-A and B not | | | | present | | (Universal recipient) | | | +-----------------------+-----------------------+-----------------------+ a. Blood typing test Determining blood group antigens on surface of RBCs (Both ABO blood group and Rh antigens) Done before Blood transfusion b. In a blood transfusion Blood types must be compatible to prevent agglutination (Clumping of red blood cells) Which is caused by antibodies c. Antibodies: Specific and bind only to the antigen they are directed against d. If RBCs are agglutinated, it will be destroyed and cleared from the body by the immune system - Rh Blood groups 1. Rh antigen present Rh positive (Rh+) -- Most common 2. Rh antigen absent Rh negative (Rh-) +-----------------------+-----------------------+-----------------------+ | Rh Blood group | Rh antigen present? | Anti-Rh antibodies | | | | present? | +=======================+=======================+=======================+ | Rh+ | Present | \- | +-----------------------+-----------------------+-----------------------+ | Rh- | Not present | Generally, not | | | | present. | | | | | | | | Only if exposed to | | | | Rh+ RBCs, antibodies | | | | to Rh antigen can | | | | develop. | +-----------------------+-----------------------+-----------------------+ - Perform a crossmatch before blood transfusion Involves mixing small amount of donor's blood with recipient's plasma and observing for agglutination.