Lecture 11 - Water and Electrolytes Flashcards
Who has the most water in the body?
Children 65%
Adults 60%
Seniors 55%
Where does most water reside in the body?
3/4 lean tissue
< 1/4 fat tissue
What groups have the smallest portion of water?
Females
Obese individuals
Elderly
Why do females have less water than males?
Females have more fat around the hips and thighs. Fat carries less water. Males typically have less fat and more lean muscle which has higher water content
What are some of waters body functions?
- Carries nutrient and waste
- Maintains structures of large molecules
- Metabolic reactions
- Solvent
- Lubricant
- Temp regulation
- Maintains blood volume
What is the difference between Extracellular fluid, intracellular fluid and interstitial fluid?
Extra: outs of the cell (including inter)
Inter: between cells
Intra: within cell
What is the AI for men and women for total water?
Men: 3.7L/day
Women: 2.7L/day
-both include food and liquids
What controls water intake?
The hypothalamus
- recognizes concentrated blood and signals thirst
- recognizes distention of stomach and decreases thirst
What is the first and second signs of dehydration?
1- Thirst
2-Weaknes, exhaustion, delirium
What are the symptoms of water intoxication?
Confusion, convulsions, death
Hyponatremia
What is hyponatremia?
Low Na levels in the blood
What happens when cells are thirsty?
Water from the blood goes to the cells, concentrating the blood. This also constricts blood vessels everywhere, when this happens around the mouth no saliva is produced
Where do we lose water from and in what order in terms of L?
Kidneys
Skin
Lungs
GI
What is the amount of water we have to lose and why?
500ml has to be lost for waste excretion
What is insensible water loss?
Water we don’t think of losing
-from skin and lungs
What is the difference between hard and soft water?
Hard –> Higher in Ca
Soft–> Higher in Na
What are some health effects of water?
Meet body fluid needs
Protect against urinary stones and constipation
What is the fluid balance of cells?
2/3 fluid inside the cell
1/3 outside
How do you control the movement of water?
Cant control the movement of water but we use electrolytes to control the water movement
-electrolytes attract water
What are the 3 Kidney hormones?
Antidiuretic hormone
Renin
Angiotensen