FS2) Toxicology

Toxicology

The study of poisons

Toxicologists

Detect and identify drugs & poisons in the body fluids, tissues & organs

SOME SUBCATEGORIES…

• Environmental toxicologists

• Occupational toxicologists

• Forensic toxicologists

Environmental Toxicologists

Describes what toxins surround us and their concentrations

• Some amount of toxins in our environment is okay, but over a certain threshold, it’s dangerous

• Anti-venoms: What snakes have it, how to make it

Occupational Toxicologists

Works with toxins found in workplaces to ensure safety

• Radiation, drug testing, etc…

Forensic Toxicologists

Deals with toxins related to the law

• Workplace drug-use testing

• Postmortem drug testing

• Investigation of contraband materials

______% of evidence now being testing in U.S. crime labs are CRIME RELATED… _______% of drugs tested in a toxicology lab (alcohol and cocaine)

75, 90

Toxicology of Alcohol

Alcohol is a Central Nervous System DEPRESSANT

Alcohol is absorbed into the bloodstream, takes effect in about 5-10 mins when it starts to enter the stomach and intestines

• Activates dopamine ‘pleasure pathways”

• Deactivates the frontal lobe —> causes disinhibition; decreases ability to think rationally and make good decisions

• Gastric (stomach) and liver damage

GABA (Gamma-aminobutryic acid)

INHIBITORY: neurotransmitter that stops reactions from happening

Increases the permeability of Cl- ions into the cell, which hyperpolarizes it, therefore making it less likely to fire

• A message fires at -55mV, but the GABA INCREASES the initial mv from -70 to -80mV by binding on to the receptors, making it more difficult for this threshold to be met

Alcohol helps GABA with its inhibitory effects, therefore preventing a neuron from firing by making it even MORE NEGATIVE/MORE SLOW

Gultamate

EXCITATORY; neurotransmitter that is responsible for sending messages for neurons to fire

Alcohol binds onto the receptors to prevent the glutamate from binding and sending the message; therefore has sedative effects

Neurotransmitter

Particles that neurons use to communicate with one another via synapses between neurons

Pituitary Gland

Controls the flow of water released by the body via urine; alcohol weakens this control

• Results in dehydration and leads to hangovers

Alcohol: Weight Loss

Alcohol holds many calories; consistent use can lead to a noticeable weight gain

• Any shots of basic liqueur (~100 calories)

• Beer (~150-200 calories per bottle)

• Wine (~100 calories per glass

• Margarita (~500 calories for 8oz and 700 calories for 12oz)

• Cup of Ice Cream (~250 calories)

Alcohol Stats

• 300-500 billon dollar industry

  • 7+ billion in marketing alone

• Average consumption is about 2.8 gallons per year (600+ drinks) in 2021

• ~174.4 million Americans drink

• ~30 million have a “drinking problem”

Effects of Ethyl Alcohol on the BRAIN: MAIN effect is on the…

FOREBRAIN, which is responsible for executive function; this region is affected first

• Reasoning, planning, parts of speech, movement, emotions, and problem-solving

REAR PORTIONS are affected next

• Movement, orientation, recognition, perception of stimuli, perception and recognition of auditory stimuli, memory, speech

  • Cerebellum —> Spatial awareness & coordinating movements

FINALLY, THE MEDULLA IS AFFECTED (brainstem); the medulla is responsible for managing breathing and other involuntary actions

• Slowing them down to dangerous levels can be fatal

Effects of Alcohol

• Third of the girls who had gotten pregnant between the ages of 14-21 were had been drinking

• 91% reported that sex wasn’t planned

• HALF of all newly-reported AIDS cases are for young people aged 14-21

IMPAIRS JUDGEMENT: 29% (2018) of traffic fatalities involve alcohol

Long-Term Effects

• Jaundiced kidneys

  • Turns yellow as a result of the body’s inability to break things down

• Cirrhotic liver/ other liver problems

How does alcohol get into your body?

• 20% of alcohol is absorbed into the bloodstream across the walls of the stomach

• 80% is absorbed across the walls of the small intestine

Creates a DELAY in the consuming of the alcohol itself and when you feel the effects

What factors affect how FAST alcohol is absorbed into the bloodstream?

Time taken to consume the drink

The AMOUNT of alcohol absorbed doesn’t change

Types of Alcohol

LOWER CONCENTRATION: Absorbed slowly, takes LONGER to get into your system

HIGHER CONCENTRATION: Absorbed quickly; takes LESS time to get into your system

What if there’s food in your stomach?

Still going to get drunk, just going to be absorbed SLOWER

• Food is blocking the way into the stomach and small intestine

• Carbohydrates and other foods that are easy to absorb (simple carbs) slow it down the most

Weight of Drinker

The bigger you are, the more space there is for alcohol is spread out— the more spread out in the system, the less you’ll feel the effects

Sex of the Drinker

Different NUMBER and TYPE of dehydrogenase enzymes

Men

• Have more enzymes that break down alcohol

• Have the more active version of said enzyme

Women

• Have fewer enzymes that break down the alcohol

• Have higher fat than water in the body context, since alcohol goes to the water, the alcohol can spread to fewer places; feel the effects MORE; more concentrated

DOESN’T CHANGE WITH TOLERANCE

One drink is equal to…

1) One mixed drink with 1.5 fluid ounces (44mL) of 80-proof liquor (vodka, gin, scotch, bourbon, brandy, rum, etc.)

2) 5 fluid ounces (148mL) of wine

3) 12 fluid ounces (355 mL) of beer or wine

ALL 3 ARE EQUAL IN ALCOHOL CONTENT

Maximum blood-alcohol concentrations in the blood may not reach it’s maximum, until _____ minutes after consumption depending on how much alcohol is consumed & over how much time

30 - 90

Alcohol: Fluids

The spinal and eye fluids can be used to determine the blood alcohol content

How fast can your body break down alcohol?

0.015 - 10.02 BAC per hour; 0.015 BAC == 0.015g alcohol per 100mL of blood

• About 1 drink to 1.5 drinks

Job of the Liver (Process)

The liver breaks things down, specifically, it breaks down alcohol via oxidation

• About 95% of alcohol in your body is broken down by the liver

• Acetaldehyde (toxic) → After this molecule is deoxeginated again, it becomes…

• Acetic acid

Excretion

Is the elimination of alcohol in unchanged state

Blood Alcohol Content (BAC)

There is an EXACT PROPORTION between the amount of alcohol exhaled compared to the concentration of alcohol in the blood

Measuring alcohol in the body: Direct Method

Get a blood sample and test it for alcohol

Measuring alcohol in the body: Indirect Method

Use a breathalyzer

Anatomy: Arteries & Veins

Arteries carry blood away from the heart

Veins carry blood into the heart

• Usually carries blood that isn’t oxeygenated

Pulmonary artery oxygenations are reversed

Capillaries

EXTREME thin veins; blood cells are moving very slowly because they have to go one cell at a time

• Allows for more CONTROL to diffuse blood into certain areas of the body

• Allows for oxygen to attach and remove waste products like carbon dioxide

• Under more pressure than veins

Path Alcohol travels throughout the body

• 20% of alcohol is absorbed from the walls of the stomach to the veins

• 80% of the alcohol passes from the walls of the small intestine to veins in the liver

Blood that goes to the lungs, exhales carbon dioxide and alcohol out of the body via the alveoli and through the bronchi

In alveoli, oxygen enters the blood and carbon dioxide leaves it

At 34 degrees Celsius, the ratio of alcohol in the blood to alcohol in the alveoli is _______

2’100:1

• For every 2’100 alveoli, there is one ____ of alcohol

• 1 mL of blood contains the same amount of alcohol as 2’100mL alveolar breath

Getting Blood Drawn…

Concentration of alcohol in arterial blood will be considerably higher than blood in the veins

• During elimination venous blood has higher BAC values

Breathalyzer

Measures the alcohol content of alveolar breath by measuring the amount of alcohol consumed via the absorption of light using a SPECTROPHOTOMETER

In the presence of alcohol, a dichromate ion (ORANGE) will convert the alcohol into a chromium ion (GREEN); the unused orange mixes with green to make a BLUE SOLUTION; sensor looks for the concentration of BLUE to determine the alcohol concentration

The more GREEN, the more alcohol there is; uses the ratio between orange:green

• There’s a sensor that requires you to breath a certain minimum amount