chapter 10 Flashcards
water functions
- lubricant and cleanser
- spinal fluid protects against shock
- regulates body temp
what regulates ph in blood plasma
- co2, electrolyte concentrations, total weak acid concentrations
exercise induced metabolic acidosis
- ATP used rapidly, adp, p and H+ produced
- H+ acidifies muscle cells, buffered by lactate
- alkaline ingestion helps buffer against acidosis
intracellular fluid
- inside cells
- 2/3 of body water
- lowest in NA and Cl, highest in K and protein
extracellular fluid
- outside ells
- highest in Na and Cl
- lowest in K
- protein between intracellular and interstitial levels
interstitial fluid
- lymph, blood plasma, extracellular fluid
- lowest concentration of protein
thirst machanism
- blood volume decreases, secretes saliva and stimulates thirst centre
- get thirsty and drink
antidiuretic hormone assists in fluid intake
- released when dehydrated, molarity increases
- acts on kidneys
- results in: more H2O resorbed in kidneys
electrolytes
- Na, Cl, K
- important for life and affects distribution of water
sodium DRI
- UL: 2300mg
- above can cause hypertension, cancer, athesma, osteoporosis
canadian Na intake
- average adult consumes 3400mg Na
hypertension
- almost 18% of canadians 12 and over have high bp
- 140/90 mm or greater
blood pressure
- systolic bp: when heart beats
- diastolic: when heart at rest
- normal bp: 120/80 mmhg
hypotension
- 90/60
salt sensitive
- higher blood pressure rise with greater NA intake
- influenced by nutiritonal status
hypertension and diet
- less Na in diet, lower the BP
- average Na intake: 3400 mg
- reduction in NA will reduce bp
potassium intake of canadians
- recommended: 4700mg
- average canadian: 2500-3500
- fruit and veg best sources
fluid balance during exercise
- dehydration can affect performance and be a threat to health
- drink early and often
- consume cold beverages
- be aware of overhydration
sports drinks
- enhance water absorption and replace lost electrolytes
- not needed if ecercising < 1hr
- 1.25 per gk wt lost
- helps to replace Na and K
hyponatremia
- abnormally low blood sodium level
- also in athletes who consume too much water
- can also result from prolonged diarrhea, vomiting, sweating
absorption and excretion of alcohol
- absorbed by simple diffusion along gi tract
- 20% absorbed in stomach
- 90% of alcohol is metabolized by liver, 5% is excreted into urine and remainder eliminated by lungs
pathways of alcohol metabolism
- cytosol alcohol dehydrogenase (ADH) for breaking down small amounts of alcohol
- microsomoal ethanol oxidizing system (MEOS) important for breaking down large amounts of alcohol
- alochol metabolized by colon bacterial DH to yield acetaldehyde - toxic
adverse effects of alcohol consumption
- alcohol poisoning
- binge drinking
- blackout drinking
- interference with organ funciton
- interferes with nutritional status
physiological impact of alcohol metabolism
- sex difference: women have a lower activity of stomach adh and less body water
- products of alcohol metabolism by adh promote fat synthesis
- reactive oxygen molecules are generated in meos pathway
acute effects of alcohol consumption
- when alcohol intake exceeds ability of liver to break it down, alcohol intoxication or poisoning can occur
- circulation of alcohol affects CNS, breathing and heart ratte
long term alcohol use
- causes malnutrition
- generates toxins and free radicals that cause liver damage, hypertension, heart disease, stroke, increased cancer risk
moderate drinking
- can have benefits
- not more than 1 per day for women or 2 per day for men
