Blood

What do you know???

Why is it called the "river of life"?

Function: 1. Transport: gases, nutrients, wastes 2. Transport of processed molecules: -substances made in one part of body and transported to another part of body -ex. Vitamin D, Lactic acid 3. Transport of regulatory molecules 4. Regulation of pH & osmosis pH 7.35-7.45 5. maintain body temperature 6. Protection against foreign substances 7. clot formation

Components:Plasma and formed elements

Plasma: -55% of blood -made of: 90% water, salts, plasma proteins, nutrients, hormones, wastes, gases -plasma proteins (made by liver): 1. albumin - helps osmotic pressure of blood to keep blood in bloodstream 2. Fibrinogen - clotting protein 3. globulins - antibodies for defense and lipid transport proteins are not used by cells

plasma amount is regulated by body systems 1. if proteins too low - liver produces more 2. if blood too acid (acidosis) - or too basic (alkalosis) - kidneys and lungs help bring pH back to normal (pH 7.35-7.45) plasma also distributes body heat through body

Formed elements (cells) -45% of blood - include red blood cells (erythrocytes) white blood cells (leukocytes) platelets (thrombocytes)

Red blood cells - erythrocytes function - carry oxygen from lungs to cells and carbon dioxide too -are anucleate at maturity -contain few organelles -contain hemoglobin - (protein with iron)

-lack mitochondria -make ATP by anaerobic fermentation - so don't use oxygen they carry -biconcave disk (think snow tube!) -1000 RBCs to 1 WBC -add thickness to blood -1 cell = 250 million hemoglobin molecules -5 million cells /cubic mm -contains 12-18 g hemoglobin/100ml

Problems with RBCs: 1. anemia - decrease in oxygen carrying capacity of blood causes: low # of RBCs RBCs don't have enough hemoglobin in them Several types of anemia: a. hemorrhagic anemia - due to blood loss b. hemolytic anemia - bacteria lyse RBCs c. pernicious anemia - lack of B12 d. aplastic anemia - bone marrow destruction e. iron deficiency anemia - low iron in diet

f.sickle cell anemia cause: genetic defect - abnormal hemoglobin made (must have 2 copies) mostly in people of African descent RBC becomes sickle shaped

-become sickle shape when low oxygen - during -become sickle shape when low oxygen - during exercise, anxiety, stress -dam up blood vessels -low oxygen delivery to cells -symptoms: pain, jaundice, tired, inability to fight infection -diagnosis: blood test -treatment: folic acid -helps produce RBC, pain meds -prognosis: can live full life, some deaths immune to malaria

2. polycythemia - increase in number of RBCs cause: bone marrow cancer (polycythemia vera), high altitudes (secondary polycythemia) increases blood viscosity, makes circulation harder especially if clogged arteries

Leukocytes- white blood cells (WBC) function: fight off infection caused by bacteria, viruses, parasites, tumor cells -removes dead cells and debris -4,000-11,000/mm3 -have nuclei (DNA) -move in and out of blood vessels via diapedesis (amoeboid movement) -respond to chemicals released in body -positive chemotaxis -body can produce double amount in a few hours

Leukocytosis- Greater than 11,000 cells/mm3 -indicates an infection Leukopenia - low white blood count -caused by meds - corticosteroids, anticancer agents Mononucleosis -cause Epstein Barr virus -symptoms - sore throat, fever, tired, enlarged spleen -spread in saliva, mucus - "kissing disease" -diagnosis - blood test, questions -treatment-goes away on own

Leukemia- cancer of the blood cells -body produces abnormal cells -different types acute leukemia - blood cells remain immature (blasts) chronic leukemia -some blasts present, progresses more slowly -symptoms:-fever, chills, fatigue, frequent infections, swollen lymph nodes, easy bruising/bleeding, bleeding gums, joint pain -diagnosis:medical history, blood test, bone marrow biopsy, lumbar puncture -treatment:radiation therapy, chemotherapy, bone marrow transplant

Leukocytes - two main groups of cells: 1. Granulocytes - have granules in cytoplasm a. neutrophils - most common, alive for 10-12 hours phagocytes, found in pus http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/B/Blood.html#neutrophils

b. eosinophils - reduce chemicals to decrease b. eosinophils - reduce chemicals to decrease infection, rid body of parasitic worms, regulates inflammatory response http://www.funsci.com/fun3_en/blood/blood.htm

c. basophils - release histamine to promote c. basophils - release histamine to promote inflammation, releases heparin - prevents clots http://www.funsci.com/fun3_en/blood/blood.htm

2. Agranulocytes- lack granules a. lymphocytes- smallest white blood cells -produce antibodies http://www.funsci.com/fun3_en/blood/blood.htm

made in bone marrow: B-lymphocytes - oversee immunity of bodies' humors (fluids) -mature in bone marrow T-lymphocytes - arise from cells that migrate to thymus for maturity (2-3 days) regulated by thymosin hormone -circulate through body - go after pathogens infected cells both of these migrate via blood to lymph nodes, spleen and other lymphoid tissues

precursor to macrophage b. monocytes - largest white blood cell become macrophages - phagocytize bacteria, dead cells http://www.funsci.com/fun3_en/blood/blood.htm precursor to macrophage

Platelets -fragments of large multinucleated cells (megakaryocytes) -aka thrombocytes -300,000/mm3 -produced in red bone marrow -function - clotting of blood

Hematopoiesis -blood cell formation -happens in red bone marrow -stay in bone marrow until mature, then go to rest of body

hemocytoblast = stem cell that gives rise to all other blood cells two types: lymphoid stem cell - becomes lymphocytes myeloid stem cells - all other cells red blood cells live ~ 120 days gotten rid of by phagocytes in spleen, liver and other tissues synthesize hemoglobin young red blood cell - reticulocyte - still contains ER takes 5 days to mature from hemocytoblast

Erythrocyte production control

white blood cells and platelets is stimulated by hormones (colony stimulating factors (CSFs) and interleukins) stimulates bone marrow to produce leukocytes exposure to bacterial toxins stimulates macrophages/lymphocytes to release CSFs and interleukins thrombopoietin - hormone that helps makes platelets

Hemostasis -blood clotting process- results from break in blood vessel Three major steps: a. platelet plug formation b. vascular spasms c. coagulation

1. Platelet plug formation: -if blood vessels break - collagen fibers are exposed, cause platelets to get "sticky" -anchored platelets release chemicals that attract more platelets to make platelet plug (white thrombus) 2. Vascular spasms: -platelets release serotonin - causes blood vessels to spasm -narrows blood vessel, decreases blood loss, before clotting

3. Coagulation events: -thromoboplastin is released by injured tissues -PF3 (phospholipid) coats platelets and reacts with thromobplastin, other clotting factors and calcium ions - cause clotting cascade -prothrombin activator converts prothrombin in plasma to thrombin (enz) -thrombin joins with fibrinogen to make long hairlike fibers called fibrin -fibrin forms mesh network that traps other platelets and RBCs to form clot -clot hardens to form scab -serum = plasma minus clotting proteins - clear fluid that seeps from wounds -takes 3-6 minutes to clot, once clotting cascade starts -applying gauze and pressure speed up clotting

Hemostasis disorders: 1. thrombus = clot that develops and stays in unbroken blood vessel -if forms in heart vessels - causes heart attack -if floats freely in blood stream = embolus -no problem unless gets into small vessels it can't get through. cerebral embolus = stroke -anything that causes roughening of blood vessel can cause clotting -severe burns, physical blows, cholesterol build-up, blood pooling -treatment: anticoagulants - aspirin, heparin, coumadin

Bleeding disorders: 1. thrombocytopenia - insufficient # of platelets in blood -normal movements causes bleeding from blood vessels -petechiae = purplish blotches -cause- bone marrow cancer, radiation, drugs 2. Vit K deficiency - Vit K needed by liver to produce clotting factors 3. Hemophilia - "bleeder's disease" -lack of certain clotting factors -factor VIII = 75% - most common -sex linked trait -use transfusions or injections of clotting factor

Blood Groups -Karl Lansteiner (1900) discovered four different types -due to specific presence or absence of agglutinogens (carbs, glycoproteins or glycolipids) on surface of RBC

24 blood groups with 100 antigens -rarest type MN ABO blood groups based on type A and type B antigens agglutinogens = antigens = substance that the body recognizes as foreign -stimulates the release of antibodies (agglutinins)for defense -we tolerate our own, get reaction if come in contact with different types of blood antigens -antibodies "recognize" and attach to RBC antigen causing agglutination (clumping) -can cause kidney failure

To figure out what blood type children would be: use Punnett Squares Type A blood = AA or AO Type B blood = BB or BO Type AB blood = AB Type O blood = OO so if parents are: AB and AO, children could be A B A AA AB O AO BO

Rh factor = another antigen on the surface of RBCs can be Rh + (has antigen) or Rh- (no antigen) -named after the Rhesus monkey where it was first discovered -normally not a problem unless mother is Rh- and baby is Rh+ -first pregnancy - mother starts building antibodies against Rh factor -second pregnancy - mother's body will try to reject baby -baby can be born with hemolytic disease -baby is anemic, hypoxic, brain damage if left untreated -treatment: transfusing the baby at birth

now injection of RhoGam (anti Rh gamma globulin)is all that is needed to prevent mother from producing antibodies

Importance of blood typing: -so no agglutination (clumping) cross matching = testing to make sure donor blood is compatible How is it done? test blood with antiserum (Anti A and Anti B) RBCs of type A will clump with anti A serum RBCs of type B will clump with anti B serum RBCs of type AB will clump with both anti A and Anti B) RBCs of type O will not clump with either anti A or Anti B Rh factor typing is same but with anti Rh

When is blood typing needed?

Blood tests: 1. red blood cell count males - 4.6-6.2 million RBC/mm3 females 4.2-5.4 million RBC/mm3 2. Hemoglobin 14-18 gm/100ml - males 12-16 gm/100ml 3. Hematocrit = % of total blood volume composed of RBC 40-50% of total blood volume (male) 38-48% of total blood volume (female)

4. White blood cell count total # of WBC in blood 5000-9000/ml3 5. platelet count 250,000-400,000/ml3

Developmental aspects of blood -embryo - liver and spleen also make blood cells -by 7th month of development - red marrow does most production -fetal hemoglobin (HbF) is different than mature hemoglobin - has more oxygen carrying capability -after birth have hemoglobin (HbA) =typical -jaundice happens in infants when liver can't process all of the destroyed RBCs fast enough