PHS 3342 Lecture Notes - Lecture 1: Buffy Coat, Ketone Bodies, White Blood Cell
28 Apr 2018
School
Department
Course
Professor
January 9, 2018
Blood
Introduction to Blood
Blood is the only fluid CT in the body
-Needs to be formed of cells, have a ground structure (plasma), and have fibres to qualify as a tissue
•NB: only has fibres during clotting
Composed of formed elements (erythrocytes, leucocytes, platelets) suspended in plasma
-Differs from other tissues because not all of the cells are complete cells (RBCs have no nucleus, platelets are cell
fragments)
-Plasma = 55% of whole blood
-Buffy coat (WBCs and platelets) = <1% of whole blood
-Erythrocytes = 45% of whole blood
-Hematocrit = packed cell volume (mainly composed of erythrocytes)
Physical characteristics:
-Colour is scarlet (O2-rich) to dark red (O2-poor)
-More viscous than H2O
-***pH = 7.35-7.45
•<7.35: acidosis - more common concern (ex. Accumulation of lactic
acid or ketone bodies)
•>7.45: alkalosis
-Temperature = ~38°C
-~8% body weight (~5.5 L in males, ~5 L in females)
Functions:
-Transportation
•O2 from lungs and nutrients from GI tract to cells
•Metabolic wastes from cells to kidneys and lungs
•Hormones to target organs
-Regulation
•Temperature: distribution, conservation, dissipation
•pH in body tissues (plasma proteins, bicarbonate)
-Bicarbonate buffer system: CO2 + H2O <—> H2CO3 <—> H+ + HCO3-
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January 9, 2018
•Allows acid to be converted to water and carbon dioxide to protect from acidosis
•Can’t completely prevent acidosis, but it does help protect against it (Band-Aid not a cure)
•Adequate fluid volume: important for maintaining blood pressure and circulation
-Protection
•Platelets, plasma proteins, blood clotting
•Antibodies, complement, WBCs
Blood Plasma
Straw-coloured
Components: 91.5% water + 8.5% solutes (mostly proteins)
-Water: transport medium, carries heat (due to high heat capacity)
•NB: the water will absorb the heat, but the temperature of the blood as a whole undergoes only small changes
-Plasma proteins: those proteins confined to blood
•Mainly synthesized by liver (except for immunoglobulins, which are produced by lymphocytes)
•Represent 6-8% of total weight of the plasma
•Establish an osmotic gradient between blood and interstitial fluid
•Partially responsible for plasma’s capacity to buffer pH changes
•Three major groups:
-Albumins (54%): nonspecific carrier of various molecules, important blood buffer, major osmotic protein
(normally between 280-300 mOsmols)
-Globulins (35%): immunity
•α and β globulins: some serve transport functions, others are important in clotting
-Ex. Angiotensin is an α-globulin
•Immunoglobulins (IgGs): antibodies
-Fibrinogen (7%): blood coagulation
•Precursor to fibrin threads, which link everything together in the blood clot
-Other solutes: electrolytes, nutrients, enzymes, hormones, gases and waste products (ex. urea, uric acid,
creatinine, ammonia, bilirubin)
-NB: major osmotic ion is Na+ - lots of sodium present in the plasma
Plasma vs. serum:
-Plasma: contains fibrinogen, blood cells are still free
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Document Summary
Blood is the only uid ct in the body. Needs to be formed of cells, have a ground structure (plasma), and have bres to qualify as a tissue: nb: only has bres during clotting. Composed of formed elements (erythrocytes, leucocytes, platelets) suspended in plasma. Differs from other tissues because not all of the cells are complete cells (rbcs have no nucleus, platelets are cell fragments) Buffy coat (wbcs and platelets) = <1% of whole blood. Hematocrit = packed cell volume (mainly composed of erythrocytes) Colour is scarlet (o2-rich) to dark red (o2-poor) ***ph = 7. 35-7. 45: <7. 35: acidosis - more common concern (ex. Accumulation of lactic acid or ketone bodies: >7. 45: alkalosis. ~8% body weight (~5. 5 l in males, ~5 l in females) Transportation: o2 from lungs and nutrients from gi tract to cells, metabolic wastes from cells to kidneys and lungs, hormones to target organs. Regulation: temperature: distribution, conservation, dissipation, ph in body tissues (plasma proteins, bicarbonate)
