Lecture #4 Flashcards
Functions of the Circulatory System
- Transport
- Protection
- Regulation
Components of Blood
Blood: a liquid connective tissue consisting of cells and extracellular martix
- Plasma: matrix of the blood (yellow)
- Formed elements: blood cell and cell fragments
4-6L
Hematocrit
- Erythrocytes are heaviest and settle first 37% to 52% tv
- White blood cells and platelets 1%tv
• Buffycoat - Plasma
• 47%to63%
• Complex mixture of water,
proteins, nutrients, hormones, gases
Blood Plasma
- Plasma proteins
- Nitrogenous compounds
- Nutrients
- Dissolved O2, CO2, and nitrogen
- Electrolytes
Viscosity
resistance of fluid flow
4.5-5.5 more viscous than water
Osmolarity
Total molarity of dissolved particles that cannot pass through
the blood vessel wall
Formed Elements
- Erythrocytes RBC
- Platelets
- Leukocytes WBC
Leukocytes contain
Granulocytes (with granules)
a) Neutrophils
b) Eosinophils
c) Basophils
Agranulocytes(w/out granules)
a) lymphocytes
b) Monocytes
Erythrocytes (RBC) Functions
- Carry oxygen from lungs to cell tissues
2. pick up co2 from tissues to lungs
Hemoglobin
consist of 4 protein chains
2 a and 2b chains
Regulation of Erythropoiesis
- negative feedback control
- stimuli for erythropoiesis (production of RBC)
Hemolysis
Rupture of RBCs
Hemoglobin Disposal
Regulated to prevent kidney failure
Erythrocytes Disorders
Anemia = Deficiency In RBCs or hemoglobin
Polycythemia = excess RBCs
Causes of Iron Deficiency Anemia
Causes:
- lack of iron intake
- blood loss
- metabolic iron deficiency
Antigens
Enables body to distinguish own cells from foreign(on surface of the cell)
Antibodies
binds antigens
destruction
Agglutination
bind 2 or more antigen molecules
Transfusion incompatibility
Karl Landsteiner (Nobel Prize) Discovered blood types: A, B, and O
Hemostasis
the cessation of bleeding
Hemorrhage
excessive bledding
Hemostatic mechanisms
- Vascular spasm (1st)
- Platelet plug formation (2nd)
- Blood clotting (coagulation) (3rd)
Platelet Form
small fragments of
megakaryocyte cells
Normal platelet count—130,000- 400,000 platelets/L
1st - Vascular Spasm
Prompt constriction of broken vessel
2nd - Platelet Plug formation
Platelet plug, Platelets bind, contract, pull walls of vessel
together
3rd - Coagulatin (clotting)
most effective
Objective: convert fibrinogen to fibrin
sticky protein–adheres to wall so vessels seal
Extrinsic
Initiated by clotting factors released from damaged blood vessel
• Fastest (2-6min)
Intrinsic
Initiated by
clotting factors in the blood (plasma or platelets)
