Alcohol, H20, Na Flashcards
how does alcohol affect the brain?
narcotic sedative and depressant (Sedates inhibitory nerves)
describe conversion of ethanol to acetyl coa
refer to diagram
requires NAD+ (niacin). and Coenzyme A (acetyl CoA).
causes build up of NADH and H+
why do men have lower blood alcohol levels than women if they drink the same amount?
men produce alcohol acetaldehyde dehydrogenase (ADH) in the stomach and liver (where women only produce in the liver) = more breakdown of alcohol occurs before alcohol reaches the blood stream = men will absorb less alcohol in the small intestine because more of it was broken down already.
describe absorption of alcohol in the small intestine
alcohol is rapidly absorbed and gets absorbed and metabolized before most nutrients. (body wants to get rid of it fast)
this reflects that:
- alcohol can’t be stored
- alcohol is potentially toxic
what is the impact of drinking alcohol with food on alcohol absorption?
food slows down the rate of alcohol absorption and metabolism in the stomach. Thus it takes longer for to alcohol to reach absorption in the small intestine to the blood stream
how does alcohol affect the liver
- primary site of alcohol metabolism (liver is the first organ that alcohol reaches)
- liver usually prefers to metabolize fatty acids into triglycerides, but alcohol forces the liver to metabolize it first
- alcohol can cause irreversible damage to liver cells = impairs liver’s ability to metabolize fats = liver deteriorates
how does alcohol affect the liver
- primary site of alcohol metabolism (liver is the first organ that alcohol reaches)
- liver usually prefers to metabolize fatty acids into triglycerides, but alcohol forces the liver to metabolize it first
- alcohol can cause irreversible damage to liver cells = impairs liver’s ability to metabolize fats = liver deteriorates
- alcohol metabolism uses up the NAD that is needed for other metabolic processes = slows down glycolysis, TCA, ETC, etc = no gluconeogenesis or protein synthesis
what is cirrhosis? describe how this develops?
irreversible liver damage (caused by alcohol, hep B or C, iron toxicity (hemachromatosis)
-accumulation of fibrosis tissue, scars and nodules and connective tissue = impaired function of the liver
caused by acetyl coa being converted to fatty acids instead of entering the TCA cycle = damages liver cells because liver doesn’t prefer to metabolize alcohol = fatty liver (1st stage) = fibrosis (2nd) = cirrhosis (3rd) = leads to carcinoma = need liver resection/transplant
what happens if more than excess amounts of alcohol is consumed?
- maximum rate of alcohol breakdown is set by the amount of alcohol dehydrogenase available
- if more alcohol arrives at the liver than the enzymes can handle, the extra alcohol circulates around the body until liver enzymes are available to process it
higher risk of malnutrition:
- more empty cals = less nutrient intake from foods
- destroys thiamin
- destroys liver = lower vit D activation
dehydration
increases fatty acid synthesis
decreases protein synthesis
steps of liver deterioration?
effects of fatty liver:
central nervous system
ketosis
lactate production
- fatty liver: interferes with distribution of nutrients and o2 to liver cells
- reversible with abstinence from alcohol - fibrosis: some liver cells are dead from fatty liver
- least reversible damage to liver
with a fatty liver, it is difficult to generate glucose from protein = no gluconeogenesis = blood glucose can plummet = irreversible damage to the central nervous system = decreased protein synthesis = body uses acetyl coa to make ketone bodies = higher acidity
describe fetal alcohol synthdrome
alcohol is directly toxic to babies when consumed by pregnant mothers (alcohol crosses placenta freely).
Often occurs because the mother doesn’t know they’re pregnant in the early stages
can cause:
- irreversible brain damage
- growth restriction
- cognitive impairment
- facial and vision abnormalities (ie. far away eyes)
describe MEOS
microsomal ethanol oxidizing system
in liver and mitochondria
NADPH + H + 1/2o2 = NADP + H20
induced by alcohol and drugs
functions of electrolytes
- fluid compartments and balance
- acid/base balance
- muscle contractions
- conduction of nerve impulses
who should increase intake of water?
- pregnant and lactating women
- darrhea and womiting
- fever
- heavy exercise
- elderly
- hot environment
is K+ or Na+ on outside/inside of cells?
inside: K+
outside: Na+
mechanisms of thirst?
role of ADH?
- when you feel thristy = already dehydrated (because thirst lags behind the body’s need)
- thirst often confused for hunger
- when blood volume or pressure falls too low = extracellular fluid is too concentrated =hypothalamus signals pituitary gland to release ADH (antidiuretic hormone) = stimulates kidneys to reabsorb water
- hypothalamus signals thirst
hormones in homeostasis of water balance?
ADH retains water
Renin and aldosterone retains Na
angiotensin constricts blood vessels
what does renin do (blood volume and pressure)
released when kidneys respond to low bp
renin causes kidneys to reabsorb sodium = accompanied by water retention = helps restore blood volume and bp
role of angiotensin
angiotensin is a vasoconstrictor that narrows the diameter of blood vessels = raises the blood pressure
renin converts angiotensinogen to angiotensin
role of aldosterone
hormone secreted by adrenal glands.
signals kidneys to retain more Na = more h2o is retained = regulates bp
when more water is needed, less is excreted
describe the DASH diet
more fruits and veg = more K+
lower fat
restrict Na+
increase K+, fibre, mg, Ca
helps:
- lower b and cholesterol
- prevent/reduce hypertension
