Chapter 3 BLOOD

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1.Transportation• O2 and CO2

• nutrients(glucose, lipids, amino acida)• waste products(e.g. metabolites)2. Homeostasis• Regulation hormones• pH(buffer pairs) body temperature3. Protection• blood coagulation• Immunity

functions of blood

Key points in this chapter:

1.the formation and roles of the osmotic pressure of plasma.

2.the functions of erythrocytes and the factors that effect the production of erythrocytes.

3.functions of leukocytes.4.the characteristics of platelets and the functions of platel

ets in the physiological hemostasis.5.intrinsic and extrinsic pathway of blood coagulation.6.the anticoagulative functions of antithrombin , hepariⅢ

n.7.fibrinolysis and diagram the fibrinolytic system

homeostasis

1.Components and Physicochemical Properties of Blood

1.1 Components of blood

Blood

Blood cells （ 45 ％） WBC

RBC

PLT

Plasma（ 55 ％）

Water （ 91 ％ of plasma ）Inorganic constituents(1% of plasma)

e.g. ions:Na+, Cl-, K+, Ca2+

Nutrients: glucose, amino acids, lipids and vitamins

Organic constituents

Protein albumin （ A ） globulin （ G ） fibrinogen （ F ）

Waste products e.g. urea

Dissolved gases O2, CO2

Hematocrit（红细胞比容）The volume of red bolld cells as a percentage of centrifuged whole blood.

M:40%~60%, F:37%~48%,

Blood Volume

Blood volume equal approximately to 7%-8% of body weight.

e.g. a person weigh 70kg, then blood volume is 4.9L, if take the hematocrit to be 45%

erythrocyte volume=0.45×4.9L=2.2L

plasma volume=4.9L-2.2L=2.7L

1.2 Physical and chemical properties of blood

1.2.1specific gravity of blood

» Depending on hematocrit and protein composition» Whole blood:1.050-1.060» Plasma:1.025-1.035» Red blood cells:1.090

1.2.2.Viscosity of blood

Relative viscosity of whole blood 4-5depending on hematocrit

Relative viscosity of plasma 1.6-2.4 related to the protein composition of the plasma

1.2.3. Osmotic pressure of plasma the pressure that must be applied to the pl

asma to prevent the net flow of water into the plasma is termed the osmotic pressure.

(300mmol/L=5330mmHg) （ Fig. ）

The osmotic pressure of a solution depends on the number of solute particles in the solution, not on their chemical composition and size.

Osmotic pressure of plasma

Crystalloid osmotic pressure

concept: Pressure gengrated by all crystal substances, particularly NaCl.

role ： Important in maintaining fluid balance across cell membranes

Colloid osmotic pressure concept:pressure generated by plasma protein

s, particularly albuminrole ：Approximately 25 mmHg, but important in fluid transfer across capillaries

1.2.4.Plasma pHNormal range:

7.35-7.45

Buffer systems in blood NaHCO3/H2CO3

Na2HPO4/NaH2PO4

Pro-Na/Pro

Hb

Lung and kidney Fig

2. Physiology of blood cells

2.1 Red blood cells(erythrocytes)

2.1.1 Count

RBCcount

M: (4.0~5.5) ×1012/L

W: (3.8~4.6) ×1012/L

Hemoglobin concentration

M: 120~160g/L

W: 110~150g/L

2.1 Red blood cells(erythrocytes)

Morphology

Biconcave discs

Without a nucleus

2.1.2 RBC function

① transport O2 、 CO2

②buffering

Hb+H+=HHb

2.1.3 Production of RBC

(1)Nutritional requirements for erythropoiesis

Many vitamins, minerals, and proteins

iron

folic acid, VitB12

intrinsic factoranemia

红细胞成熟因子

合成原料

*erythropoietin(EPO)

*androgen促红细胞生成素

雄激素

(2) Regulation of erythropoiesis

在哪生成？

2.2 White blood cells (Leucocytes)

2.2.1 Types of WBC

WBC count

GranulocytesNeutrophils 2.0 ～ 7.0 50 ～ 70

Eosinophils 0 ～ 0.5 1 ～5

Basophils 0 ～ 0.1 0 ～1

Monocytes 0.1 ～ 0.8 1 ～ 8

Lymphocytes 0.8 ～ 4.0 20 ～40

WBC Count(×109/L) %

Total 4 ～ 10

2.2.2 WBC function

1) neutrophil ① protect the body against invading organisms

② eliminate immune complex, dead tissues, aged RBC

piapedesis phagocytosis游走性

2) basophil

① release heparin ( 肝素 )

② release histamine allergic reaction

contain granules

组织胺

3) eosinophil

① restrict allergic reaction induced by basophil and mast cell

　 a. produce PGE, that inhibit active

substance released from basophil 　　 b. engulf granules released from basophil

　 c. release histaminase

② antagonize parasites

4) monocyte-macrophage

① engulf invading organisms

② eliminate immune complex, dead tissues

③ recognise and kill tumour cell

④ activate lymphocyte

⑤ release cytokines

5) lymphocyte

T lymphocyte

B lymphocyte Immune function

2.3 Platelets(thrombocytes)

• Normal value(100-300) ×109/L• Play an important role in hemostasis( 止血）

2.3.1 Physiological properties of platelet

(1)Adhesion （粘附） Platelets adhere to the vessel wall at the sit

e of injury

(2)Aggregation （聚集） Platelets adhere to one another

纤维蛋白原或

血管血友病因子（ vWF)

Inducers of platelet aggregation

• ADP

low dose 1st reversible phase

high dose 2nd irreversible phase

• Thromboxane A2(TXA2)

• Collagen

• Thrombin

血栓烷素 A2

胶原

凝血酶阿斯匹林-

(3)Release