KINE 2P20 Lecture Notes - Lecture 11: Osmotic Concentration, Bioavailability, Osmosis
9 May 2018
School
Department
Course
Professor
Nutrition 2P20
CHPT 10
Water
- Essential nutrient that must be consumed for survival
- Polarity comes from hydrogen (+) and oxygen (-)
- Solvent (dissolved ions – electrolytes)
- Transportation (blood – oxygen and nutrients)
- Lubrication and protection
- Regulation of body temperature ~37C
- Acid-base balance
- DRI
▪ 3.7L men, 2.7L women
Osmosis
- When a selectively permeable membrane allows water to pass freely across it to
equalize the concentration of solutes on both sides
Water loss
- Kidneys regulate water loss
- ADH (antidiuretic hormone) stimulated by drop in blood volume
- ADH signals the kidney to reabsorb water and reduce the losses to restore BV
Water Intoxication
- Too much water relative to Na in the body – hyponatremia
- Causes tissues to swell by water moving out of blood and into interstitial space
▪ Tissues become hypertonic to blood
▪ Drops blood volume
- Swelling in brain – disorientation, convulsions, seizures, coma, death
- Replenish electrolytes and/or release water
Electrolytes
- Sodium, Potassium, Chloride
- Na+/K+ pump
▪ 20-40% REE
- Nerve conduction, muscle contraction, nutrient transport (glucose/AAs)
Blood pressure
- High Na+ intake causes higher extracellular (vascular) increases blood volume and blood
pressure
- Protective mechanism: trigger kidney to excrete Na+ and water to lower blood pressure
- Low BP:
▪ renin-angiotensin-aldosterone to increase Na+ resorption (water follows)
▪ ADH to increase water absorption/retension
Potassium
- RDA 4700mg/d
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Essential nutrient that must be consumed for survival. Polarity comes from hydrogen (+) and oxygen (-) Lubrication and protection: 3. 7l men, 2. 7l women. When a selectively permeable membrane allows water to pass freely across it to equalize the concentration of solutes on both sides. Adh (antidiuretic hormone) stimulated by drop in blood volume. Adh signals the kidney to reabsorb water and reduce the losses to restore bv. Too much water relative to na in the body hyponatremia. Causes tissues to swell by water moving out of blood and into interstitial space: tissues become hypertonic to blood, drops blood volume. Swelling in brain disorientation, convulsions, seizures, coma, death. Nerve conduction, muscle contraction, nutrient transport (glucose/aas) High na+ intake causes higher extracellular (vascular) increases blood volume and blood pressure. Protective mechanism: trigger kidney to excrete na+ and water to lower blood pressure. Low bp: renin-angiotensin-aldosterone to increase na+ resorption (water follows: adh to increase water absorption/retension.
