5. FLUID BALANCE 40% 50% OVER 60 40-50% 50-60% 40-60 50% 60% 18-40 55% 65% UNDER 18 FEMALE MALE AGE TOTAL BODY WATER (AS PERCENTAGE OF BODY WEIGHT) IN RELATION TO AGE AND SEX
6.
7. Function of Water : Most of cellular activities are performed in water solutions.
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14. 16% TBW 40% TBW 4% TBW - makes up ~60% of total body weight (TBW) - distributed in three fluid compartments. Body Fluid
15. 16% TBW 40% TBW 4% TBW Fluid is continually exchanged between the three compartments.
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17. 16% TBW 40% TBW 4% TBW - not affected by electrolyte concentrations - Edema = water accumulation in tissue fluid Exchange between Blood & Tissue Fluid
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19. Water Gain Water is gained from three sources. 1) food (~700 ml/day) 2) drink – voluntarily controlled 3) metabolic water (200 ml/day) --- produced as a byproduct of aerobic respiration
20. Routes of water loss 1) Urine – obligatory (unavoidable) and physiologically regulated, minimum 400 ml/day 2) Feces -- obligatory water loss, ~200 ml/day 3) Breath – obligatory water loss, ~300 ml/day 4) Cutaneous evaporation -- obligatory water loss, ~400 ml/day 5) Sweat – for releasing heat, varies significantly
21. Regulation of Water Intake - governed by thirst. blood volume and osmolarity peripheral volume sensors central osmoreceptors hypothalamus thirst felt
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23. Regulation of Water Output - The only physiological control is through variations in urine volume. - urine volume regulated by hormones
28. 1) ADH dehydration blood volume and/or osmolality hypothalamic receptors / peripheral volume sensors posterior pituitary to release ADH H 2 O reabsorption Water retention
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30. 2) Atrial Natriuretic Factor blood volume =↑ BP atrial volume sensors atria to release ANF inhibits Na + and H 2 O reabsorption water output = ↓ BP
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38. HORMONE REGULATION: Insulin and Epinephrine = cause K+ and phosphate to move from extracellular fluid into cells Parathyroid hormone = cause Ca++ and phosphate to move from bone to extracellular fluid Calcitonin = moves calcium to bones ELECTROLYTE BALANCE
114. Acid An acid is any chemical that releases H + in solution. Base A base is any chemical that accepts H + .
115. pH is the negative logarithm of H + concentration, and an indicator of acidity. pH = - log [H + ] Example: [H + ] = 0.1 M = 10 –7 M
116. Normal functions of proteins (especially enzymes) heavily depend on an optimal pH. pH7.35-pH7.45
117. Regulation of acid-base balance 1) Chemical Buffers 2) Respiratory Control of pH 3) Renal Control of pH
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122. 3) The Protein Buffer There are three major buffers in body fluid. 1) The Bicarbonate (HCO 3 - ) Buffer 2) The Phosphate Buffer Chemical Buffers
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Editor's Notes
Sequence An action potential arrives at the presynpatic terminal causing Ca2+ channels to open, increasing the Ca2+ permeability of the presynpatic terminal. Calcium ions enter the presynpatic terminal and initiate the release of a neruotransmitter, acetylcholine (Ach), from synaptic vesicle into the presynaptic cleft. Diffusion of Ach across the synaptic cleft and binding of Ach to its receptors on the postsynaptic muscle fiber membrane opens Na+ channels and increases the permeability of the postsynaptic membrane to Na+ The increase in Na+ permeability results in depolarization of the postsynaptic membrane; once threshold has been reached a postsynaptic action potential results.