Water, Alcohol And Electrolytes Flashcards
Alcohol not considered a nutrient
While it does yield 29kJ/g, it is not considered a nutrient as it does not support the growth, maintenance or repair of the body.
Metabolic effects of alcohol
Inhibition of glucose metabolism Competition for thiamin in the glucose pathway Increase in lactic acid Increase in lipid synthesis Decrease in protein synthesis Increase in effect of drugs Interference with vitamin D and B6 synthesis Diuretic effect
Short term effects of alcohol
Depressant
- interferes with REM sleep
- increased blood flow to the skin
- rosy flush
- increase in blood pressure
- increased risk of gouty arthritis
- high risk of injury and accidents
Long term effects of alcohol
Stomach- alcohol increases acid secretion
Pancreas- pancreatic damage, secondary diabetes
Liver- direct toxin, cirrhosis (hardening of the liver)
Small bowel- change in morphology of cells- malabsorption, iron overload
Brain- depressant, sleep disturbances, acetylaldehyde acts as direct toxin, B6 and B1 deficiency
Beneficial effects of alcohol
Moderate- reduction in blood clotting
Low- antispasmodic effect upon blood vessels, increased HDL
Alcoholic drinks
Beer (4-5%)- 1.4 standard drinks in a can. 250ml standard drink
Wine (8-14%)- 100ml standard drink
Spirits (40%) - 30 ml standard drink
Water needs of the body
Water loss from lungs and skin (insensible losses) are responsible for 50% of the total water turnover
Dehydration by 2% can result in impaired physiological responses and performance
Health effects of chronic mild dehydration:
- increased risk of kidney stones
- urinary tract and colon cancer
- diminished physical and mental performance
Role of water
Carries nutrients and wage products Maintains structure of large molecules Participates in metabolic reactions Solvent Lubricant and cushion around joints, inside eyes, spinal cord and amniotic fluid in pregnancy Regulation of body temp Maintains blood volume y
Fluid and electrolyte balance
About two thirds of body fluid in cells, one third outside
- extra cellular fluid has two components- interstitial fluid and plasma.
Fluid and electrolyte balance:
- dissociation of salt in water into ions (electrolytes)
- electrolytes attract water
- movement occurs via osmosis
Proteins regulate flow of fluids and ions
Regulation of fluid and electrolyte balance
- kidneys maintain balance using ADH
- kidneys maintain electrolyte balance using aldosterone
- medications and medical conditions may interfere with fluid and electrolyte balance
- vomiting and diarrhoea cause sodium losses
- kidneys may lose too much potassium if there is adrenal hyper secretion of aldosterone
- hyperglycaemia in diabetics may cause glucose and fluid loss via the kidneys
- electrolytes are osmotic, therefore used to create movement of water in extra cellular or intracellular fluid
Role of blood
Transport: Oxygen and carbon dioxide Food molecules Ions Wastes Hormones Heat
White blood cells- immune function
Vitamin K for blood
Necessary for blood clotting, essential for function of several proteins in clotting process
- coenzyme for carboxylation of the glutamate residues of blood clotting factors
- impacts on calcium binding function of variety of proteins
- ability to bind calcium required to activate the clotting cascade
Folate for blood
Involved in DNA synthesis, amino acid metabolism, cell division, cell maturation (red blood cells)
Folate trap:
B13 dependent enzyme required to remove methyl group from THF tetrahydofolate
Inadequate B12 means folate becomes trapped as methyl THF
Implications for homocysteine metabolism
Food sources:
Vegetables, legumes, cereal products, fortification of wheat flour in baking
Folate deficiency/ toxicity for blood
Elderly, dieting, alcoholics, pregnant people, infants, adolescence, malabsorption illness people, B12 deficient all at risk.
Increased folate intake before conception and during pregnancy
Deficiency: megoblastic anaemia
- folate deficiency impairs DNA synthesis so red blood cells become megaloblasts (large, fragile, immature cells) and macrocytes (abnormally large red blood cells with short life spans)
- impairs oxygen carrying capacity- weakness, fatigue, depression, irritability, forgetfulness
Toxicity-
- hypersensitivity to supplements (hives, respiratory distress)
- may mask B12 deficiency
Vitamin B12
Obtained from meat, poultry, milk and dairy
At risk:
Vegans, reduced absorption from lack of intrinsic factors, disease of terminal ileum, parasites
Deficiency: pernicious Anaemia
- autoimmune disorder
- antibodies made to: gastric partners cells (prevent intrinsic factor and stomach acid) and intrinsic factor (antibodies bind to intrinsic factor preventing it from binding to B12 or receptions in terminal ileum)
- diagnosed with blood and bone marrow analysis and assessment of B12 absorption
- treated with intramuscular injection of hydroxycobalamin for life
Symptoms of deficiency-
- megoblastic anaemia
- neurological abnormalities - peripheral neuropathy and degeneration of spinal cord. Tingling and numbness in extremities, abnormal gait, loss of concentration, memory loss, disorientation
