Blood

What do you know???

Why is it called the "river of life"?

Function:1. Transport: gases, nutrients, wastes2. Transport of processed molecules:

-substances made in one part of body and transported to another part of body

-ex. Vitamin D, Lactic acid3. Transport of regulatory molecules4. Regulation of pH & osmosis

pH 7.35-7.455. maintain body temperature6. Protection against foreign substances7. 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 protein3. globulins - antibodies for defense and

lipid transportproteins are not used by cells

plasma amount is regulated by body systems1. if proteins too low - liver produces more2. 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 - erythrocytesfunction - 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 themSeveral types of anemia:

a. hemorrhagic anemia - due to blood lossb. hemolytic anemia - bacteria lyse RBCsc. pernicious anemia - lack of B12d. aplastic anemia - bone marrow

destructione. iron deficiency anemia - low iron in diet

f.sickle cell anemiacause: genetic defect - abnormal

hemoglobin made (must have 2 copies)

mostly in people of African descentRBC becomes sickle shaped

-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 infection, rid body of parasitic worms, regulates

inflammatory response

http://www.funsci.com/fun3_en/blood/blood.htm

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

b. monocytes - largest white blood cellbecome 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 cellstwo types:

lymphoid stem cell - becomes lymphocytes

myeloid stem cells - all other cells

red blood cells live ~ 120 daysgotten rid of by phagocytes in spleen, liver and

other tissuessynthesize hemoglobinyoung red blood cell - reticulocyte - still contains

ERtakes 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

formationb. vascular spasmsc. 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

plateletsto 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

causingagglutination (clumping)

-can cause kidney failure

To figure out what blood type children would be: use Punnett Squares

Type A blood = AA or AOType B blood = BB or BOType AB blood = ABType O blood = OO

so if parents are: AB and AO, children could beA B

A

O

AA AB

AO BO

Rh factor = another antigen on the surface of RBCscan 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 serumRBCs of type B will clump with anti B serumRBCs 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 countmales - 4.6-6.2 million RBC/mm3females 4.2-5.4 million RBC/mm3

2. Hemoglobin14-18 gm/100ml - males12-16 gm/100ml

3. Hematocrit = % of total blood volume composed of RBC40-50% of total blood volume (male)38-48% of total blood volume (female)

4. White blood cell counttotal # of WBC in

blood5000-9000/ml3

5. platelet count250,000-400,000/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