Upload
hollee-wiley
View
219
Download
9
Tags:
Embed Size (px)
DESCRIPTION
Blood Physiology / 血液的主要功能. 赖蒽茵 浙江大学医学院生理系 求是特聘教授 浙江省“千人计划”人才, 博导 [email protected]. 13:15-14:00 , May 12 , 2014 ,基础医学导论 紫金港东 2-203 , 2013 级五年制临床,共 150 人. Body Fluid = 60% of Body Weight (BW). Plasma 5% of BW. Extracellular Fluid 1/3, 20% of BW. Interstitial Fluid 15% of BW. - PowerPoint PPT Presentation
Citation preview
赖蒽茵
浙江大学医学院生理系 求是特聘教授 浙江省“千人计划”人才,博导
13:15-14:00 , May 12 , 2014 ,基础医学导论紫金港东 2-203 , 2013 级五年制临床,共 150 人
Blood Physiology / 血液的主要功能
Body Fluid = 60% of Body Weight (BW)
Intracellular Fluid2/3, 40% of BW
Extracellular Fluid1/3, 20% of BW
Plasma 5% of BW
Interstitial Fluid15% of BW
70 kg Male, 42 L
Internal environment (内环境)
Homeostasis(稳态)
Homeostasis (from the
Greek words for “same” and
“steady”):
maintenance of static or
constant conditions in the
internal environment
Walter B. Cannonhttp://www.harvardsquarelibrary.org/unitarians/cannon_walter.html
Components of Homeostasis:
Concentration of O2 and CO2
pH of the internal environment
Concentration of nutrients and waste products
Concentration of salt and other electrolytes
Volume and pressure of extracellular fluid
Body's systems operate together to
maintain homeostasis:
Skin system Skeletal and muscular system
Circulatory system Respiratory system
Digestive system Urinary system
Nervous system Endocrine system
Lymphatic system Reproductive system
How is homeostasis achieved?
Components of blood
• Plasma(血浆)• Blood Cells
– Red Blood Cells (RBC) or Erythrocytes(红细胞)
– White Blood Cells (WBC) or Leucocytes(白细胞)
– Platelets (PLT) or Thrombocytes(血小板)
Plasma includes water, ions, proteins, nutrients, hormones, wastes, etc.
The hematocrit(血细胞比容) is a rapid assessment of blood composition.It is the percent of the blood volume that is composed of RBCs (red blood cells).
the volume of red blood cells as a
percentage of centrifuged whole blood
M: 40~50%
F: 37~48%
Hematocrit ( packed cell volume, 血细胞比容)
Properties of blood
1. Specific Gravity(比重)Depending on hematocrit & protein composition
Whole blood: 1.050~1.060
Plasma: 1.025~1.035
Red blood cells: 1.090
2. Viscosity(粘度)
Relative viscosity of whole blood 4~5 depending on hematocrit
Relative viscosity of plasma 1.6~2.4 related to the protein
composition of the plasma
Properties of blood
3. Osmotic Pressure(渗透压)
• The osmotic pressure of a solution depends on the number of solute particles in the solution, not on their chemical composition and size
Properties of blood
• Plasma osmotic pressure (~300 mOsm/L)– Crystalloid Osmotic Pressure(晶体渗透压)
• Pressure generated by all crystal substances, particularly electrolytes
• Important in maintaining fluid balance across cell membranes
– Colloid Osmotic Pressure(胶体渗透压)• Osmotic pressure generated by plasma proteins,
particularly albumin.
• Approximately 25 mmHg, but important in fluid transfer across capillaries
Properties of blood
4. Plasma pH
• Normal range: 7.35~7.45
• Buffer systems(缓冲系统) :
NaHCO3/H2CO3, Pro-Na/Pro, Na2HPO4/NaH2PO4
Hb-K/Hb, HbO2-K/HbO2, K2HPO4/KH2PO4, KHCO3/H2CO3
Properties of blood
Functions of blood• Transportation
– O2 and CO2 – Nutrients (glucose, lipids, amino acids) – Waste products (e.g., metabolites) – Hormones
• Regulation– pH– Body temperature
• Protection– Blood coagulation– Immunity
Body Fluid = 60% of Body Weight (BW)
Intracellular Fluid2/3, 40% of BW
Extracellular Fluid1/3, 20% of BW
Plasma 5% of BW
Interstitial Fluid15% of BW
Plasma
Water (92% of plasma)serves as transport medium; carries heat proteins Nutrients glucose, amino acids, lipids & vitamins
Waste products nitrogenous wastes like urea
Dissolved gasesO2 & CO2
Hormones
Plasma composition
•Albumins (白蛋白) (60-80% of plasma proteins) •most important in maintenance of osmotic balance •produced by liver
•Globulins (球蛋白) (1-, 2-, -, -)•important for transport of materials through the blood (e.g.,
thyroid hormone & iron) •clotting factors •produced by liver except -globulins which are
immunoglobulins (antibodies) produced by lymphocytes
•Fibrinogen(纤维蛋白原) •important in clotting •produced by liver
Erythrocyte Sedimentation Rate (ESR)(红细胞沉降率)The distance that red blood cells settle in a tube of blood in one
hour
Normal value,
M: 0~15 mm/h , F: 0~20 mm/h
An indication of inflammation which increases in many diseases,
such as tuberculosis & rheumatoid arthritis…
Suspension stability(悬浮稳定性)
Osmotic fragility (渗透脆性)
the susceptibility of a red blood cell to break apart when
exposed to saline solutions of a lower osmotic pressure
than that of the human cellular fluid
• Hemocytoblast stem cell• Stem cell becomes committed• Early erythroblasts have ribosomes早期的红细胞有核糖体
• Erythroblasts accumulate iron and hemoglobin红细胞积聚铁和血红蛋白
• Normoblasts eject organelles• Released as erythrocyte
Regulation of Erythropoiesis
1. Erythropoietin(促红细胞生成素)
2. Hormones: Androgen(雄激素 )
Hypoxia-inducible factor-1, HIF-1
average lifespan = about 120 days
Destruction of RBC
Macrophages engulf( 吞噬 )old RBCs Iron is salvaged Heme degrades into bilirubin
Anemia(贫血)
• Anemia is defined as a qualitative or quantitative deficiency of hemoglobin, a protein found inside red blood cells (RBCs)
• The three main classes of anemia:– excessive blood loss (acutely such as a
hemorrhage or chronically through low-volume loss)
– excessive blood cell destruction (hemolysis)– deficient red blood cell production (ineffective
hematopoiesis)
Iron deficiency anemia缺铁性贫血
WBC Count (109/L) %Granulocytes
Neutrophils 2.0~7.0 50~70Eosinophils 0.02~0.5 0.5~5Basophils 0~0.1 0~1
Monocytes 0.12~0.8 3~8Lymphocytes 0.8~4.0 20~40
Total 4~10
WBC count
Leukopoiesis (白细胞生成 )
• Myeloblasts (原始粒细胞 ) become all of the granular leukocytes (白细胞 )
• Monoblasts become monocytes • Lymphoblasts become lymphocytes
Platelets
Formed in the bone marrow from cells called megakaryocytes (巨核细胞 )
Without nucleus, but can secrete a variety of substances
normal value:
(100~300) x 109/L Average lifespan=7~14 days Play an important role in
hemostasis
1. Adhesion
Platelets adhere to the vessel wall at the site of injury
Physiological properties of platelets
von Willebrand factor, vWF
Phospholipid ( 磷脂 )
Arachidonic Acid ( 花生四烯酸 )
Phospholipase A2
TXA2
Cyclo-oxygenase
PGG2 & PGH2
PGI2
Prostacyclin synthase(Vascular endothelium)
Thromboxane synthase(Platelets)
Aggregation Anti-aggregationContraction Relaxation
Production of Platelets (Thrombocytes)
• Formation– Large multinucleated cells that pushes against the
wall of the capillary– Cytoplasmic extensions stick through and separate
Hemostasis(止血)
The arrest of bleeding following injury and the
result of 3 interacting, overlapping
mechanisms:
• Vascular spasm (血管收缩)
• Formation of a platelet plug (血小板血栓形成)
• Blood coagulation (clotting) (血液凝固)
Role of vascular endothelium in hemostasis
o Vasoconstriction: reduced blood flow facilitates contact activation of platelets and coagulation factors
o Exposure of sub-endothelial basement membrane and collagen
o Release of tissue thromboplastins ( 组织因子 )
o Synthesis of basement membrane components, tissue factor ( 组织因子 ), vWF, plasminogen activator ( 纤溶酶原激活物 ), antithrombin III ( 抗凝血酶 III), thrombomodulin ( 血栓调节蛋白 )
Clotting factors
Clotting factor SynonymsI fibrinogen纤维蛋白原II prothrombin凝血酶原III tissue thromboplastin组织因子IV Ca2+
V proaccelerin前加速素易变因子VII proconvertin前转变素稳定因子VIII antihemophilic factor抗血友病因子IX plasma thromboplastin component血浆凝血活酶X Stuart-Prower factorXI plasma thromboplastin antecedent血浆凝血活酶前质XII contact factor接触因子XIII fibrin-stabilizing factor纤维蛋白稳定因子
Blood coagulation
The liver plays a critical role in producing andmodifying blood-borne proteins, including those used in the clottingpathway.
Moreover, bile salts from the liver facilitate the absorption of lipids in the diet, including vitamin K, which is required for the synthesis of prothrombin.
Knowledge that thrombin plays acentral role in clottinghas generated detailedstudies of the possiblepathways resulting inits formation:
the extrinsic pathway is the more important of the two under most circumstances.
Serum (血清)
serum = plasma – fibrinogen and
some of the other clotting factors
+ substances released by
vascular endothelial cells and
platelets
Clotting time (凝血时间 ): 4-12 min
o Serine Protease Inhibitor
Antithrombin III (抗凝血酶 III )inhibiting all serine proteases of the blood coagulation
system, including:
o thrombin
o factor IXa, Xa, XIa, XIIa
Anticoagulants (抗凝物质)
Heparin (肝素)A polysaccharide (多糖 ) produced by the tissue mast cells and
the basophils of circulating blood
Interfering primarily with the action of thrombin after
combining with antithrombin III
Fibrinolysis (纤维蛋白溶解)
o 2 processeso Activation of plasminogen
o Degradation of fibrin
o 4 components of plasma fibrinolysis systemo Plasminogen (纤维蛋白溶解酶原)o Plasmin (纤维蛋白溶解酶)o Plasminogen activator
o Plasminogen inhibitor
Blood types
o Erythrocytes carry on their surfaces many
antigens, but the most important and
commonly recognized are the A and B
substances and the Rhesus (Rh) factors
• inherited independent of ABO system
• Rh positive = antigen present (mainly D
antigen) & no antibodies
• Rh negative = no antigen & antibodies will be
produced if exposure occurs
Rh group/type
Transfusion is the process of replacing blood or
blood component which a body has lost in
surgery, through an accident or as a result of
medical treatment such as chemotherapy.
Blood transfusion
Sterility, Viability, Quantity, Safety & Quality
Risk from Transfusion
1. Allergic reactions to the blood or one of its
components
2. Hemolytic reaction
3. Diseases transmission, such as HIV, Hepatitis B, C
virus