Unit 1.1-1.3 Psych

Epigenetics

environment and behaviors cna cause heritable changes in gene activity without altering DNA sequence

What do epigenetics do?

Turns a gene “on” or “off”

2 main branches of nervous system

Peripheral and Central

2 branches of PNS

Somatic and Autonomic

Somatic NS

communicates sensory neurons to CNS

Autonomic NS

Involuntary functions

Branches of Autonomic NS

Sympathetic and parasympathetic

Sympathetic

Fight or flight: HR, stress hormones, respiration

Parasympathetic

Rest or digest: calms body

Sensory Neurons

Different for each sense, afferent (arrive at brain)

Motor Neurons

Connected to muscles, efferent (exit the brain)

Resting potential

-70 millivolts

Polarized

Positive outside the cell

Firing Threshold

All or none law, same intensity every time

Action potential

30 millivolts

Refractory Period

Brief period when neuron can’t fire

Reuptake

Neurotransmitters reabsorbed by neuron where it originally came from

Most abundant excitatory neurotransmitter

Glutamate

Most abundant inhibitory neurotransmitter

GABA

What does Glutamate do

strengthens synaptic connections

Acetylcholine (ACh)

All movement, learning, memory

Dopamine

Pleasure and reward

Endorphins

Painkiller, creates euphoric feelings

Epinephrine/adrenaline

Fight or flight, works with hormone to boost energy

Norepinephrine

Arousal, alertness, sleep cycle

Serotonin

Mood, appetite, sleep, dreams

Agonist

Enhances actions of neurotransmitters

Direct agonist

mimics neurotransmitter

Indirect agonist

Reputable inhibitors, neurotransmitter stays in synapse

Prozac

Inhibits reputable of serotonin

Cocaine

Inhibits reputable of dopamine

Antagonist

Inhibits action of neurotransmitters, bind but do not stimulate, blocks it form being released or binding to receptor site

Botox

Antagonist for ACh, blocks ACh from reaching receptors

Thorazine

Antagonist for dopamine

All psychoactive drugs

After mental states

Blood brain barrier

Prevents/allows chemicals from blood to brain

4 categories of psychoactive drugs

Depressants, opioids, stimulants, hallucinogens/psychedelics

Heroin

Agonist for endorphins

Depressants

slows/inhibits CNS: drowsiness, sedation, sleep

Alcohol

Depressant, agonist for GABA

Opiates/Opiods

Agonist for endorphins: heroin, fentanyl

Stimulants

Activate sympathetic NS, increase brain activity, HR

Caffeine

Most widely used drug, release dopamine, antagonist for adenosine

Cocaine

Stimulant, agonist for dopamine

Hallucinogens

Create sensory and perceptual distortions