Blood Its in you to give!

Blood  If you took a snapshot of where blood is at any given moment, there would be 10 % is in the lungs, 5% heart, and 85% throughout the rest of the body.  The temperature is 38 degrees C, which is slightly warmer than the overall body temperature.

Physical Characteristics of Blood  Thicker (more viscous) than water and flows more slowly than water  Temperature of degrees F  pH 7.4 ( )  8 % of total body weight  Blood volume 5 to 6 liters in average male 4 to 5 liters in average female hormonal negative feedback systems maintain constant blood volume and osmotic pressure

3 major functions of blood  1.Transportation  2.Protection  3.Regulation

1.Transportation  transporting of all substances necessary for cellular metabolism  This is done through respiration, nutrition and excretion

Transportation - respiration  O2 goes to the tissue via RBCs  O2 is picked up from the caps and binds with Hb (O2 carrying protein in RBC)  O2 is released from the Hb as blood flows through the caps  O2 diffuses into the ISF and then into the cells  CO2 from the tissue cells is released from the Hb and exhaled.

Transportation - Nutritive  Blood has a nutritive function  it carries absorbed products of digestion through the liver to the cells of the body for nourishment

Transportation - excretory  Blood has an excretory function  metabolic wastes, excess water and ions, and other molecules in plasma (fluid aspect of blood) are filtered through blood vessels of the kidneys and excreted in urine

2.Protection  Protection against injury / blood loss (clotting)  Protection against foreign microbes or toxins (infection) introduced into the body  Clotting mechanism protects against blood loss when vessels are damaged  Leukocytes (WBCs) provide immunity - phagocytosis

3.Regulatory - homeostasis  Regulation by carrying hormones  Body Temperature maintenance  pH regulation  Fluid volume regulation, water content in cells

Functions of Blood  Transportation O2, CO2, metabolic wastes, nutrients, heat & hormones  Regulation helps regulate pH through buffers helps regulate body temperature  coolant properties of water  vasodilatation of surface vessels dump heat helps regulate water content of cells by interactions with dissolved ions and proteins  Protection from disease & loss of blood

Major components of blood  Blood is a type of connective tissue  Cells suspended in the fluid intercellular matrix is called plasma  Cells are RBCs, WBCs, platelets from bone marrow  Blood is thicker than water as you know and you can’t get blood from a stone  Volume varies with body size; ave 70 kg man has 5 L, roughly 10% and varies with changes in the proportions of tissues - more or less fat etc.

At the macro level

Components of Blood  Hematocrit 55% plasma 45% cells  99% RBCs  < 1% WBCs and platelets

Major components of blood  1.Plasma  2.Formed elements

Plasma  Functions is to transport nutrients, gases, vitamins, regulate fluid electrolytes and balance pH  Blood plasma is a clear pale yellow fluid  Mostly water dissolved proteins, hormones, nutrients, minerals and wastes

Formed Elements of Blood  Red blood cells ( erythrocytes )  White blood cells ( leukocytes ) granular leukocytes  neutrophils  eosinophils  basophils agranular leukocytes  lymphocytes = T cells, B cells, and natural killer cells  monocytes  Platelets (special cell fragments)

Hematocrit  Percentage of blood occupied by cells female normal range  % (average of 42%) male normal range  % (average of 46%)  testosterone  Anemia not enough RBCs or not enough hemoglobin  Polycythemia too many RBCs (over 65%) dehydration, tissue hypoxia, blood doping in athletes

 Globin protein consisting of 4 polypeptide chains  One heme pigment attached to each polypeptide chain each heme contains an iron ion (Fe+2) that can combine reversibly with one oxygen molecule Hemoglobin

 Contain oxygen-carrying protein hemoglobin that gives blood its red color 1/3 of cell’s weight is hemoglobin  Biconcave disk 8 microns in diameter increased surface area/volume ratio flexible shape for narrow passages no nucleus or other organelles  no cell division or mitochondrial ATP formation  Normal RBC count male 5.4 million/drop ---- female 4.8 million/drop new RBCs enter circulation at 2 million/second Red Blood Cells or Erythrocytes

 Because hemoglobin is a major component and this reflects the capability of blood to carry O2, it is often measured medically.  Polycythemia is an increased Hb level  Anemia is a decreased Hb level  When you want to know the % of RBCs in the blood is known as hematocrit (HCT)  RBC count million/mm3 for a male 4.8 million/mm3 female

Transport of O2, CO2 and Nitric Oxide  Each hemoglobin molecule can carry 4 oxygen molecules from lungs to tissue cells  Hemoglobin transports 23% of total CO2 waste from tissue cells to lungs for release combines with amino acids in globin portion of Hb  Hemoglobin transports nitric oxide & super nitric oxide helping to regulate BP iron ions pick up nitric oxide (NO) & super nitric oxide (SNO)& transport it to & from the lungs NO causing vasoconstriction is released in the lungs SNO causing vasodilation is picked up in the lungs

RBC Life Cycle  RBCs live only 120 days wear out from bending to fit through capillaries no repair possible due to lack of organelles  Worn out cells removed by fixed macrophages in spleen & liver  Breakdown products are recycled  Bilrubin is one of the breakdown products and is a yellow pigment

Leukocytes or WBCs  Main role is phagocytosis and antibody production  WBCs are granular or agranular based upon the ability of the cell or hold gram stain in the lab

WBC Anatomy and Types  All WBCs (leukocytes) have a nucleus and no hemoglobin  Granular or agranular classification based on presence of cytoplasmic granules made visible by staining granulocytes are neutrophils, eosinophils or basophils agranulocytes are monocyes or lymphocytes

Leukocytes or WBCs  Granular WBCs - red/orange cytoplasm granules  The shape of the nucleus and staining properties of the cytoplasm granules distinguish one WBC from the other  There are 3 types of granular WBCs  1.Eosinophils  2.Basophils  3.Neutrophils

WBCs  Eosinophils -allergic reactions - immune complexes curing allergic reaction lessening the severity of the reaction, inactivates chemicals released with allergic reactions, phagocytosis, parasite elimination

Eosinophils (Granulocyte)  Nucleus with 2 or 3 lobes connected by a thin strand  Large, uniform-sized granules stain orange-red with acidic dyes do not obscure the nucleus  Diameter is 10 to 12 microns  2 to 4% of circulating WBCs

Eosinophil Function  Leave capillaries to enter tissue fluid  Release histaminase slows down inflammation caused by basophils  Attack parasitic worms  Phagocytize antibody-antigen complexes

WBCs  Basophils - release chemicals (heparin for anticoagulation and histamine for inflammatory control) during allergic reactions

Basophils (Granulocyte)  Large, dark purple, variable-sized granules stain with basic dyes obscure the nucleus  Irregular, s-shaped, bilobed nuclei  Diameter is 8 to 10 microns  Less than 1% of circulating WBCs

Basophil Function  Involved in inflammatory and allergy reactions  Leave capillaries & enter connective tissue as mast cells  Release heparin, histamine & serotonin heighten the inflammatory response and account for hypersensitivity (allergic) reaction

WBCs  Neutrophils - phagocytes

Neutrophils (Granulocyte)  Polymorphonuclear Leukocytes or Polys (PMN’s)  Nuclei = 2 to 5 lobes connected by thin strands older cells have more lobes young cells called band cells because of horseshoe shaped nucleus (band)  Fine, pale lilac practically invisible granules  Diameter is microns  60 to 70% of circulating WBCs

Neutrophil Function  Fastest response of all WBC to bacteria  Direct actions against bacteria release lysozymes which destroy/digest bacteria release defensin proteins that act like antibiotics & poke holes in bacterial cell walls destroying them release strong oxidants (bleach-like, strong chemicals ) that destroy bacteria

Agranular WBCs  round / kidney shaped nucleus  possess cytoplasm granules but are not visible with the light microscope because of small or poor staining quality  2 types – Lymphocytes & Monocytes

Agranular WBCs  Lymphocytes - natural killer cells  Monocytes - macrophages during phagocytosis

Lymphocyte (Agranulocyte)  Dark, oval to round nucleus  Cytoplasm sky blue in color amount varies from rim of blue to normal amount  Small cells microns in diameter  Large cells microns in diameter increase in number during viral infections  20 to 25% of circulating WBCs

Lymphocyte Functions  B cells destroy bacteria and their toxins turn into plasma cells that produces antibodies  T cells attack viruses, fungi, transplanted organs, cancer cells & some bacteria  Natural killer cells attack many different microbes & some tumor cells destroy foreign invaders by direct attack

Monocyte (Agranulocyte)  Nucleus is kidney or horse-shoe shaped  Largest WBC in circulating blood does not remain in blood long before migrating to the tissues differentiate into macrophages  fixed group found in specific tissues alveolar macrophages in lungs kupffer cells in liver  wandering group gathers at sites of infection  Diameter is microns  Cytoplasm is a foamy blue-gray  3 to 8% o circulating WBCs

Monocyte Function  Take longer to get to site of infection, but arrive in larger numbers  Become wandering macrophages, once they leave the capillaries  Destroy microbes and clean up dead tissue following an infection

Differential WBC Count  Detection of changes in numbers of circulating WBCs (percentages of each type) indicates infection, poisoning, leukemia, chemotherapy, parasites or allergy reaction  Normal WBC counts neutrophils 60-70% (up if bacterial infection) lymphocyte 20-25% (up if viral infection) monocytes % (up if fungal/viral infection) eosinophil % (up if parasite or allergy reaction) basophil <1% (up if allergy reaction or hypothyroid)

Complete Blood Count  Screens for anemia and infection  Total RBC, WBC & platelet counts; differential WBC; hematocrit and hemoglobin measurements  Normal hemoglobin range infants have 14 to 20 g/100mL of blood adult females have 12 to 16 g/100mL of blood adult males have 13.5 to 18g/100mL of blood

Platelet (Thrombocyte) Anatomy  Disc-shaped, micron cell fragment with no nucleus  Normal platelet count is 150, ,000/drop of blood  Other blood cell counts 5 million red & 5-10,000 white blood cells

Hemostasis  Stoppage of bleeding in a quick & localized fashion when blood vessels are damaged  Prevents hemorrhage (loss of a large amount of blood)  Methods utilized 3 vascular spasm platelet plug formation blood clotting (coagulation = formation of fibrin threads)

Vascular Spasm  Damage to blood vessel produces stimulates pain receptors  Reflex contraction of smooth muscle of small blood vessels  Can reduce blood loss for several hours until other mechanisms can take over  Only for small blood vessel or arteriole

Platelet Plug Formation  Platelets store a lot of chemicals in granules needed for platelet plug formation alpha granules  clotting factors  platelet-derived growth factor cause proliferation of vascular endothelial cells, smooth muscle & fibroblasts to repair damaged vessels dense granules  ADP, ATP, Ca+2, serotonin, fibrin-stabilizing factor, & enzymes that produce thromboxane A2  Steps in the process (1) platelet adhesion (2) platelet release reaction (3) platelet aggregation

Hemostasis  the process of stopping the flow of blood from a broken or damaged blood vessel  1. Constriction of the BV  2. Formation of platelet plug  3. Coagulation

1. Constriction of the BV  When BV is severed or damaged contraction of smooth ms in vessel wall contracts the vessel at its damaged end decreasing the size of the opening blood can escape through  Vasoconstriction or vasospasm  Lasts up to 30 mins when by then the other processes are in play

2. Formation of platelet plug  Platelet plug formation - fortunately the platelets stick to collagen and each other and this combination literally “plugs” the damaged area depending on its size  Platelet adhesion, platelet release, platelet aggregation

Platelet Adhesion  Platelets stick to exposed collagen underlying damaged endothelial cells in vessel wall

Platelet Release Reaction  Platelets activated by adhesion  Extend projections to make contact with each other  Release thromboxane A2 & ADP activating other platelets  Serotonin & thromboxane A2 are vasoconstrictors decreasing blood flow through the injured vessel

Platelet Aggregation  Activated platelets stick together and activate new platelets to form a mass called a platelet plug  Plug reinforced by fibrin threads formed during clotting process

3. Coagulation  Formation of a blood clot  Normally plasma coagulating factors (I-XII) exist that promote prostaglandin clotting, others inhibit clotting (anticoagulants)  Most of the time, anticoagulation prevails  Serious injury the balance is in flavor of clotting

Clotting Cascade  Two pathways Extrinsic – trigger is tissue trauma (outside blood) Intrinsic- trigger is within the blood (e.g blood endothelial damage)  Both pathways utilize a variety of clotting factors to increase the activation of the system towards the COMMON PATHWAY  End result of both is conversion f fibrinogen to fibrin, which forms the loose threads or mesh that form the mechanical clot

Clotting Cascade see page 683

Homework! –Yes indeedy!  Page 418  G1,G2,G3  G4,G5  G6  Page 425 no. 12,13 and 15