Lecture 19 - Ethanol Flashcards
what is alcohol?
a hydrocarbon with an attached OH functional group
a water soluble alcohol which crosses membranes
ethanol (EtOH)
beer and whiskey/scotch are made from:
grain
wine is made from:
grapes (sugars)
jin and vodka are made from:
potatoes
rum is made from:
molasses
brandy is made from:
fruit
tequila is made from:
agave
how much EtOH is in one drink?
13.98g (per every 0.6oz)
what are the four stages of alcohol use?
1) abstinent: no drinking
2) moderate: 1-2 drinks over the course of a few days
3) bingeing: 4-5 drinks on one occassion in the last 30 days
4) heavy (alcoholic)
EtOH is mostly absorbed in the:
small intestine
does a low pH modify EtOH?
no (why the stomach doesn’t absorb EtOH)
is blood alcohol content (BAC) higher in males or females per drink?
females (different body composition, physically smaller)
a full stomach will slow someone’s overall blood alcohol content (BAC) because:
it slows the passage of EtOH into the stomach
what is the formula for blood alcohol content?
BAC = (mg EtOH) / (100mL blood)
larger people have a lower BAC because:
they have a greater body volume
leaner people have a lower BAC because:
greater water volume in the body (more vol for EtOH to distribute into)
the small size of EtOH allows it to pass into the:
brain
true or false: females tend to be smaller and leaner than men
false, they are smaller but are LESS lean
do men and women distribute alcohol differently?
yes
go review slide 162
I hear your heartbeat to the beat of the drum (bum bum!)
what are the acute effects of alcohol consumption on cognition?
- inhibited decision making and judgements
- unstable mood and heightened emotions
- decreased anxiety
- increased aggression
- increased addiction
- affects sleep cycles
- impaired memory
- impaired balance and coordination
- vision impeded and inhibited taste and smell
- reduced perception of pain
what are the acute effects of alcohol consumption on circulation?
- dilates blood vessels of the skin
- reduces blood clotting (thins blood)
- increased HDL levels
what are the acute effects of alcohol consumption on the kidneys?
inhibited ADH and increased urination
what are the acute effects of alcohol consumption on the GI system?
- increased salivation and appetite
- increased gastric HCl secretion
- increased insulin sensitivity in non-diabetics
people with large deposits of adipose tisse have a higher blood alcohol content (BAC) because:
it’s harder for the EtOH to diffuse out of the bloodstream
metabolism of EtOH is described by:
zero order kinetics (linear elimination curve)
what are the main enzymes invovled in alcohol metabolism?
alcohol dehydrogenase and aldehyde dehydrogenase
how much alcohol is metabolized by the body per hour?
7-8g (remember: one drink has ~14g)
how much BAC is eliminated per hour?
0.015 BAC
do males or females metabolize alcohol faster?
males
the acute effects of EtOH are:
biphasic
what are the two phases of alcohol consumption:
1) BAC rises: stimulant
2) BAC declines: depressant
what causes the two phases in alcohol consumption?
administration (rise) and metabolism (fall)
the stimulant effects of alcohol are:
increased sociability and decreased anxiety (especially in adolescent animals)
alcohol affects perceptions because it interacts with:
brain receptors
what type of receptors does EtOH impact?
glutamate (Glu) and GABA receptors
EtOH tilts the balance of neuronal activation towards:
hyper-polarization (inhibition)
at lower concentrations of EtOH, there is strong _____ of GABAa receptors
potentiation
at higher concentrations of EtOH, there is strong _____ of Glu-NMDA receptors and voltage gated Ca++ channels
inhibition
what is the overall effect of alcohol on neurons?
neuronal inhibition (sedative-like effects)
at lethal doses of alcohol (BAC 0.4-0.5) people can asphyxiate due to:
depressed activity in autonomic centres
GABAa receptors are part of the:
Cys-loop ligand-gated channel superfamily
heteropentameric receptors with 2 alpha subunits, 2 beta subunits, and 1 other (gamma) subunit
GABAa receptors
what kind of ions are conducted by GABAa receptors?
Cl- ions (hyper-polarizing)
NMDA receptors are part of the:
ionotropic Glu receptor superfamily
heterotetrameric receptors that contain 2 NR1 subunits and either 2 NR2 or 2 NR3 subunits
NMDA receptors
what kind of ions are conducted by NMDA receptors?
Ca++ and Na+ (depolarizing)
why is alcohol addictive?
it releases dopamine in the brain
how does alcohol cause the release of dopamine in the brain?
inhibits GABA neurons (causes disinhibition of dopamine neurons)
vasodilation gives the sensation of warm skin, but there is actually:
decreased core body temperature
the loss of stomach mucosal lining leads to:
ulcers
how does alcohol consumption give someone ‘the spins’?
- EtOH permeates the endolymph and cupula in the ears
- BAC starts to decline
- EtOH diffuses out of the cupula before the endolymph
- cupula is now more dense than the endolymph and doesn’t stabilizes when lying down
- sensory fibers are activated (brain interprets this as motion)
the mechanism of metabolic alcohol tolerance is due to:
liver adaptation (the more you drink, the more you can drink)
in people with a high alcohol tolerance, there is an:
upregulation of liver enzymes that metabolize alcohol
EtOH is _____ which can be a problem in heavy drinkers who can simultaneously suffer from malnutrition
calorie dense
EtOH can account for ____% of caloric intake in heavy drinkers
50% or more
heavy EtOH intake can cause the brain to metabolize _____ instead of glucose
acetate
true or false: most alcoholic beverages have no nutritional value
true
