Ch 20: The BloodCh 20: The Blood

Discuss the composition of blood including the functions of the various components

Explain the anatomy and functions of the red blood cells, including a description of blood typing

Discuss the types of white blood cells found in the blood and give the functions of each

Give a brief accounting of the platelets

Review hemopoiesis, including RBC and leukocyte formation

Functions of Blood

Distribution - nutrients, wastes, hormones, gases, etc.

Self-sealing – hemostasis

Disease/ infection fighting

Blood = connective tissue

extracellularmatrix:Plasma

specialized cells:

(= Formed elements)

RBCs

WBCs

Plateletscolor ?volume ?

Plasma CompositionPlasma Composition

Water 92%

Plasma proteins 7% Other solutes

1%

Transports organic and inorganic molecules, formed elements, and heat

Plasma ProteinsPlasma Proteins

Albumin (60%) Major contributor to osmotic concentration of plasma. Transport of lipids and steroid hormones

Globulins (35%) Transport ions, hormones, lipids; immune function

Fibrinogen (4%) Essential component of clotting system (conversion to insoluble fibrin)

Regulatory proteins (< 1%) ????

Other Solutes

Electrolytes: Normal extracellular fluid ion composition (????)

Organic nutrients: glucose, FA, AA

Organic wastes: urea, bilirubin

Difference between Plasma and Interstitial Fluid :

Plasma has more:Plasma has more: Dissolved O2 O2 diffuses out into tissue Dissolved proteins (too big to cross caps.)

» Albumins » Globulins

– globulins

– and globulins

» Fibrinogen

Similar concentration: Salts & small molecules

serum = plasma -serum = plasma -

Difference between

plasma and serum?

. . . . 2 more things:

Most plasma proteins are made in liver. Exception: ?

Lipoproteins = particles containing lipids (cholesterol & triglycerids) and proteins (albumins & globulins)

Formed ElementsFormed Elements

Red and White Blood Cells

Platelets

Platelets WBCs

RBCs

.1%

99.9%

Formed Elements cont.Formed Elements cont.Why whitewhite blood cells???

RBCs = Erythrocytes

Measured by hematocrit or PCV

Most abundant blood cell: 1000 RBCs/1 WBC

Contain hemoglobin, carry O2

Very regular shape - biconcave discs

Anucleate: Lifespan ~ 120 days replacement rate ~ 3 mio RBCs / sec

Structure of Hemoglobin (Hb)Structure of Hemoglobin (Hb)

Fe ion in heme group reversibly binds O2

How many oxygen

molecules can 1

Hb molecule

carry?

ABO & Rh ABO & Rh Blood TypesBlood Types

Blood groups (types) based on specific Blood groups (types) based on specific RBC surface antigens (= proteins)RBC surface antigens (= proteins)

> 30 common varieties of antigens > 30 common varieties of antigens known. Most important ABO & Rhknown. Most important ABO & Rh

blood type ?

ABO Blood typing: ABO Blood typing: 4 combinations possible4 combinations possible

A surface antigen = blood type A B surface antigen = blood type B both surface antigens = type AB neither surface antigen = type O

Rh surface antigen = + blood type no Rh antigen = negative blood type

. . . 2 - 8 months after birth:

Anti-A and anti-B antibodies can be Anti-A and anti-B antibodies can be formed in plasma !formed in plasma !

normally NO anti Rh present

Transfusion ReactionTransfusion of incompatible blood can be fatal!

Universal Donor vs. Universal Donor vs. Universal RecipientUniversal Recipient

Only for emergencies - must be given slowly !

Clinical Brief

Anemia: p. 536

Reduced oxygen carrying ability of blood. Causes??

Polycythemia: Erythrocytosis: excessive increase in RBCsPolycythemia vera:

Blood Doping: p. 545

Via direct transfusion, orEPO use

WBCs = LeukocytesWBCs = Leukocytes

Quantity and type determined by differential WBC count

Circulating WBCs are only a small fraction of total WBCs. Most are located in ?

Diapedesis

Chemotaxis

Granulocytes and Agranulocytes

Neutrophil (= PMN)Neutrophil (= PMN)

Up to ~ 70% (~ 2/3) of circulating WBCs

Cytoplasm packed with pale granules containing lysosomal enzymes

phagocytic

EosinophilEosinophil

~ 2% - 4% of circulating WBCs

Granules stain with eosin

Increased in allergies and parasitic infections

BasophilBasophil

< 1% of circulating WBCs

Granules stain with basic dyes and contain histamine

Discharge of histamine promotes inflammation at site of injury (Similar to mast cells)

MonocyteMonocyte

~ 2% - 8% of circulating WBCs Large kidney shaped nucleus In tissue called Macrophage

LymphocytesLymphocytes

~ 20% - 30% of circulating WBCs Relatively small (slightly larger than RBCs) Large round nucleus B, T, NK

Platelets = ThrombocytesPlatelets = Thrombocytes

Cell fragments of Megakaryocytes

(~ 4,000 thrombocytes per Megakaryocyte)

~ 160 m

Lifespan ~ 12 days

involved in blood clotting

Abnormal Blood Cell Counts

Leukopenia < 2,500/ L (normal 6000 – 9000)

Leukocytosis > 30,000/ L

Thrombocytopenia: < 80,000/ L (normal ~ 350,000)

Thrombocytosis: > 1,000,000/ L

Also

Lymphopenia vs. _____________

_________vs. Neutrophilia

Hemopoiesis = Blood Cell FormationHemopoiesis = Blood Cell Formation

Hemocytoblasts: One type of stem cell for all blood cells

In red bone marrowIn red bone marrow

. . . then differentiation into 4 types of progenitor stem cells:

Erythroblast

Myeloblast

Monoblast

Lymphoblast

Fig 20.8