White blood cells Platelets Red blood cells Artery.

White blood cells

Platelets

Red blood cells

Artery

• Deliver O2

• Remove metabolic wastes

• Maintain temperature, pH, and fluid volume

• Protection from blood loss- platelets

• Prevent infection- antibodies and WBC

• Transport hormones

Plasma-55%

Formed elements-45%

Buffy coat-<1%

90% Water8% Solutes:• Proteins

Albumin (60 %)Alpha and Beta GlobulinsGamma Globulinsfibrinogens

• Gas• Electrolytes

• Organic NutrientsCarbohydratesAmino AcidsLipidsVitamins

• Hormones• Metabolic waste

CO2Urea

• Leukocytes

• Platelets

• Erythrocytes (red blood cells)

• Leukocytes (white blood cells)

• Platelets (thrombocytes)

Erythrocytes

Erythrocyte7.5m in dia Anucleate- so can't reproduce; however, repro

in red bone marrow Hematopoiesis- production of RBC Function- transport respiratory gases Hemoglobin- quaternary structure, 2 chains

and 2 chains Lack mitochondria. Why? 1 RBC contains 280 million hemoglobin

molecules Men- 5 million cells/mm3

Women- 4.5 million cells/mm3

Life span 100-120 days and then destroyed in spleen (RBC graveyard)

Hematopoiesis

• Hematopoiesis (hemopoiesis): blood cell formation –Occurs in red bone marrow of

axial skeleton, girdles and proximal epiphyses of humerus and femur

Hematopoiesis

• Hemocytoblasts (hematopoietic stem cells)– Give rise to all formed elements– Hormones and growth factors push the cell

toward a specific pathway of blood cell development

• New blood cells enter blood sinusoids

Erythropoiesis

• Erythropoiesis: red blood cell production

– A hemocytoblast is transformed into a proerythroblast

– Proerythroblasts develop into early erythroblasts

Erythropoiesis

– Phases in development1. Ribosome synthesis

2. Hemoglobin accumulation

3. Ejection of the nucleus and formation of reticulocytes

– Reticulocytes then become mature erythrocytes

Figure 17.5

Stem cell

HemocytoblastProerythro-blast

Earlyerythroblast

Lateerythroblast Normoblast

Phase 1Ribosomesynthesis

Phase 2Hemoglobinaccumulation

Phase 3Ejection ofnucleus

Reticulo-cyte

Erythro-cyte

Committedcell

Developmental pathway

Regulation of Erythropoiesis

• Too few RBCs leads to tissue hypoxia• Too many RBCs increases blood

viscosity• Balance between RBC production and

destruction depends on– Hormonal controls – Adequate supplies of iron, amino acids,

and B vitamins

Hormonal Control of Erythropoiesis

• Erythropoietin (EPO)–Direct stimulus for erythropoiesis

–Released by the kidneys in response to hypoxia


• Causes of hypoxia– Hemorrhage or increased RBC destruction

reduces RBC numbers– Insufficient hemoglobin (e.g., iron

deficiency)

– Reduced availability of O2 (e.g., high altitudes)


• Effects of EPO– More rapid maturation of committed bone

marrow cells– Increased circulating reticulocyte count in

1–2 days

• Testosterone also enhances EPO production, resulting in higher RBC counts in males

Formation & Destruction of RBCs

Anemia- when blood has low O2 carrying capacity; insufficient RBC or iron deficiency.Factors that can cause anemia- exercise, B12 deficiencyPolycythemia- excess of erythrocytes, viscosity of blood;8-11 million cells/mm3

Usually caused by cancer, tissue hypoxia, dehydration; however, naturally occurs at high elevationsBlood doping- in athletesremove blood 2 days before event and then replace it; Epoetin;- banned by Olympics.

Sickle-cell anemia-

HbS results from a change in just one of the 287 amino acids in the chain in the globin molecule.

Found in 1 out of 400 African Americans.

Abnormal hemoglobin crystalizes when O2 content of blood is low, causing RBCs to become sickle-shaped.

Homozygous for sickle-cell is deadly, but in malaria infested countries, the heterozygous condition is beneficial.

Genetics of Sickle Cell Anemia

Genetics of Sickle Cell AnemiaGenetics of Sickle Cell AnemiaGenetics of Sickle Cell AnemiaGenetics of Sickle Cell Anemia

GranulocytesNeutrophils- 40-70%Eosinophils- 1-4%Basophils- <1%

AgranulocytesMonocytes- 4-8%

Lymphocytes- 20-45%

Never let monkeys eat bananas

4,000-11,000 cells/mm 3

Basophil Eosinophil

Neutrophil

Lymphocyte

Monocyte

platelet

neutrophil

neutrophilRBC

eosinophil

monocyte

lymphocyte

lymphocytebasophil

monocyte

ID WBC’s

Leukocyte Squeezing Through Capillary Wall

• Leukopenia

• Abnormally low WBC count—drug induced

• Leukemias

• Cancerous conditions involving WBCs

• Named according to the abnormal WBC clone involved

• Mononucleosis• highly contagious viral disease caused by

Epstein-Barr virus; excessive # of agranulocytes; fatigue, sore throat, recover in a few weeks

Platelets

• Small fragments of megakaryocytes• Formation is regulated by

thrombopoietin• Blue-staining outer region, purple

granules• Granules contain serotonin, Ca2+,

enzymes, ADP, and platelet-derived growth factor (PDGF)

Figure 17.12

Stem cell Developmental pathway

Hemocyto-blast Megakaryoblast

PromegakaryocyteMegakaryocyte Platelets

Hemostasis- stoppage of bleeding

Tissue Damage

Platelet Plug

Clotting Factors

Platelets: 250,000-500,000 cells/mm3

Hemostasis:

4. Coagulation

1. Vessel injury

2. Vascular spasm

3. Platelet plug formation

Hemostasis(+ feedback)

Prothrombin

Thrombin

Fibrinogen Fibrin

Clotting Factorsthromboplastin

Traps RBC & platelets

Platelets release thromboplastin

Blood Clot

Fibrin thread

Platelet

RBC

Disorders of Hemostasis

• Thromboembolytic disorders: undesirable clot formation

• Bleeding disorders: abnormalities that prevent normal clot formation

Thromboembolytic Conditions

• Thrombus: clot that develops and persists in an unbroken blood vessel– May block circulation, leading to tissue death

• Embolus: a thrombus freely floating in the blood stream– Pulmonary emboli impair the ability of the body to

obtain oxygen– Cerebral emboli can cause strokes

Thromboembolytic Conditions

• Prevented by– Aspirin

• Antiprostaglandin that inhibits thromboxane A2

– Heparin• Anticoagulant used clinically for pre- and

postoperative cardiac care

– Warfarin• Used for those prone to atrial fibrillation

Thrombocytosis- too many platelets due to inflammation, infection or cancer

Thrombocytopenia- too few platelets• causes spontaneous bleeding• due to suppression or destruction of bone

marrow (e.g., malignancy, radiation)– Platelet count <50,000/mm3 is diagnostic – Treated with transfusion of concentrated

platelets

• Impaired liver function– Inability to synthesize procoagulants

– Causes include vitamin K deficiency, hepatitis, and cirrhosis

– Liver disease can also prevent the liver from producing bile, impairing fat and vitamin K absorption

Bleeding Disorders

• Hemophilias include several similar hereditary bleeding disorders

• Symptoms include prolonged bleeding, especially into joint cavities

• Treated with plasma transfusions and injection of missing factors

Hemophiliac- a sex-linked recessive trait, primarily carried by males (x chromosome)

Type AType AType BType BType ABType ABType OType O

Blood type is based on the presence of 2 major antigens in RBC membranes-- A and BBlood type Antigen Antibody

A A anti-BB B anti-A

A & B AB no anti bodyNeither A or B O anti-A and anti-B Antigen- protein on the surface of a RBC membrane

Antibody- proteins made by lymphocytes in plasma which are made in response to the presence of antigens.They attack foreign antigens, which result in clumping (agglutination)

Type A

ABO Blood TypesABO Blood Types

Produces Produces anti-B anti-B antibodiesantibodies

b

b

b

b

b

b

b

b

Type B


Produces Produces anti-A anti-A antibodiesantibodies

a

a

a

a

a

a a

a

aa

Type AB


Produces Produces neither neither anti-A nor anti-A nor anti-B anti-B antibodiesantibodies

Type O


Produces Produces both anti-A both anti-A and anti-B and anti-B antibodiesantibodies

a

a

a

a

a

aa

a

aa

b

b

b

b

b

b

b

b

Rh Factor and Pregnancy

RH- indicates no protein

RH+ indicates proteinRH+ indicates protein

Rh Factor and

Pregnancy

Rh+ mother w/Rh- baby– no problemRh- mother w/Rh+ baby– problemRh- mother w/Rh- father– no problemRh- mother w/Rh- baby-- no problem

RhoGAM used @ 28 weeks

Type AB- universal recipients

Type O- universal donor

Rh factor:

Rh+ 85% dominant in pop

Rh- 15% recessive

Blood Type Clumping Antibody

A antigen A anti-A serum antibody anti-b

B antigen B anti-B serum antibody anti-a

AB antigen A & B anti A & B serum -

O neither A or B no clumping w/ either anti A or B anti-a, anti-b

Figure 17.16

SerumAnti-A

RBCs

Anti-B

Type AB (containsagglutinogens A and B;agglutinates with bothsera)

Blood being tested

Type A (containsagglutinogen A;agglutinates with anti-A)

Type B (containsagglutinogen B;agglutinates with anti-B)

Type O (contains noagglutinogens; does notagglutinate with eitherserum)

Blood Type & Rh How Many Have It Frequency

O Rh Positive 1 person in 3 37.4%

O Rh Negative 1 person in 15 6.6%

A Rh Positive 1 person in 3 35.7%

A Rh Negative 1 person in 16 6.3%

B Rh Positive 1 person in 12 8.5%

B Rh Negative 1 person in 67 1.5%

AB Rh Positive 1 person in 29 3.4%

AB Rh Negative 1 person in 167 .6%

ABO Blood Types

PhenotypePhenotype GenotypeGenotypeOO i ii iAA I I A A I I AA or I or I A A

iiBB I I B B I I BB or I or I B B

iiABAB I I A A I I BB

Type A and Type B cross

IA

IA

IB i

IAiIAIB

IAIB IAi

Punnett square

INQUIRY1. What is an erythrocyte, leukocyte, and thrombocyte?2. What 2 things do red cells lack compared to white

cells?3. What dietary component is needed for the production

of red blood cells?4. The largest cells in the blood that leave the

bloodstream to become macrophages are ____.5. In an acute infection, the white cell count would show

as ______.6. Erythroblastosis fetalis , also known as hemolytic

newborn disease, occurs in ____ mothers carrying ____ fetuses.

7. What antigens and antibodies found on AB red cells?8. In a transfusion, what type blood can you give a type

O person?

White blood cells Platelets Red blood cells Artery.

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