ethanol Flashcards
(22 cards)
Why is ethanol both water- and fat-soluble significant?
A: It allows ethanol to easily cross cell membranes and be absorbed into the bloodstream.
What is Blood Alcohol Concentration (BAC)?
The number of grams of alcohol in 100 ml of blood.
What vitamin’s transporter does alcohol impair?
Thiamine (Vitamin B1)
What is the toxic intermediate in alcohol metabolism?
Acetaldehyde
What enzyme breaks down ethanol into acetaldehyde?
Alcohol dehydrogenase
What happens after acetaldehyde is formed?
It’s broken down into acetic acid and then into water and carbon dioxide.
How does ADH2C*1 genotype affect alcohol response?
Causes more adverse effects due to slower acetaldehyde breakdown
(1/1 expression has adverse effects whereas 1/2 and 2/2 has positive)
What is ethanol’s primary mechanism of action in the brain?
It acts as a positive allosteric modulator of the GABA-A receptor.
What does ethanol do to the GABA-A receptor?
Increases chloride ion flow, hyperpolarizing and inhibiting neurons.
How does ethanol affect glutamate receptors?
It inhibits NMDA and AMPA receptors, reducing excitatory signaling.
What neurotransmitter is linked to alcohol’s rewarding effects?
Dopamine (increased in the nucleus accumbens)
What is the effect of ethanol on calcium channels?
It inhibits L-type calcium channels, preventing neurotransmitter release.
At what BAC is impulse control and planning affected?
0.08 BAC (called intoxication)
What are symptoms of gross intoxication (0.16 BAC)?
Impaired vision, balance, and motor control.
What happens at 0.32 BAC?
Stupor—severe impairment in speech, vision, balance.
What causes blackouts with alcohol use?
Inhibition of new memory formation due to CNS depression.
What does alcohol do to brake reaction time?
Slows it down, even at 0.05 BAC (~120ms delay at 0.08).
What are the 3 stages of alcohol withdrawal?
Stage 1 (6–12 hrs): mild, hangover-like symptoms
Stage 2 (12–48 hrs): confusion, high BP, seizures
Stage 3 (48–72 hrs): hallucinations, delirium tremens
What drug blocks aldehyde dehydrogenase to discourage drinking?
Disulfiram
What is Type 1 alcohol addiction characterized by?
It occurs in individuals over 25, with low genetic risk but high psychosocial risk (e.g., stressful interpersonal situations).
What is Type 2 alcohol addiction characterized by?
It occurs in individuals under 25, with high genetic risk and poor impulse control.
Why do seizures occur during alcohol withdrawal?
Chronic alcohol use enhances GABA (inhibition), so when alcohol is removed, the brain rebounds with excess glutamate (excitation), disrupting the balance and increasing seizure risk.
