MHS AP Psych Modules 9, 25 & 10

What is a neuron and glial cells?

• Neurons are individual nerve cells that make up the nervous system

• Electrical and chemical process

• Transmit/receive information (from dendrites to terminal branch)

• Glial cells protect and help the neurons

Picture of neuron

Multiple Sclerosis

Happens when the myelin sheath breaks down, and leads to a range of symptoms.

Action Potential

a brief electrical charge that travels down an axon

resting potential

The electrical charge of an inactive

Depolarization

Process where the neuron's membrane becomes less negatively charged due to ions coming in.

Threshold

If the electricity in a neuron reaches a certain value, the neuron activates (action potential)

refactory period

A short break between neuron activation. Resets back to resting state.

all-or-none response

A neuron is either on or off, like a gun, no in between

Neuron graph

1: Resting potential
2: Threshold
3: Action Potential
4: Refractory Period

excitatory vs. inhibitory neural signals? Why are they important

Excitatory signals make a neuron what to fire, inhibitory signals want the neuron to not fire. If there are enough excitatory signals compared to inhibitory, the neuron fires.

Synapse

Gap between dendrite and terminal branch of a neuron. Neurotransmitters cross this gap

Neurotransmitters

Neurotransmitters fire from the sending neuron and influence whether or not the other neuron fires

Reuptake

If a neurotransmitter doesn't make it to the receiving neuron, than it gets reabsorbed the sending neuron

What are neurotransmitters

chemical messengers that cross the synaptic gaps between neurons. Influence neurons, whether they fire or not.

Acetylcholine

Enables muscle action. Undersupply can paralyze muscles/can lead to alzheimer's. Myasthenia Gravis is a autoimmune disorder whether the body produces antibodies against Ach rceptors.

Dopamine

Released to start physical movement after a pleasurable experience. Oversupply: schizophrenia. Undersupply leads to tremors/decreased mobility with Parkinson's

Serotonin

Affects mood regulation, appetite, and digestion as well as sleep/arousal. Undersupply linked to depression.

Norepinephrine

Helps control alertness and arousal, released in response to stress and initiates the fight or flight response. Undersupply can affect mood/fatigue/alertness.

Endorphins

Enhances mood, hides the feeling of pain and can reduce stress. Oversupply with opiates can disrupt or stop the body's natural opiate supply.

GABA

a major inhibitory neurotransmitter. Reduces brain activity. Oversupply linked to drowsiness, muscle weakness, and cognitive impairment. Undersupply linked to anxiety, depressed mood, and seizures.

Glutamate

A major excitatory neurotransmitter; involved in memory. Increases brain activity in learning and memory. Oversupply linked to seizures/migranes. Undersupply linked to cognitive impairment and learning difficulties.

Substance P

Involved in body's perception of pain. Says "I'm hurt" to the brain. Oversupply linked with chronic pain/inflammation. Undersupply linked to a reduced pain sensation. Opposite of endorphins

What are agonists/antagnists. How does it relate to drugs.

Agonists increase neurotransmitter activity by blocking reuptake. Antagonists promote reuptake and decrease neurotransmitter activity. Drugs that inhibit reuptake lead to more neurotransmitter action which can lead to more dopamine.

What are psychoactive drugs?

chemicals that change perceptions and moods. Good in moderation but could lead to substance abuse.

What behaviors do psychologists looked for when diagnosing substance use disorder?

• Diminished control over using the drug
• Diminished social functioning from using
• Person continues using despite dangers/harm
• Person continues using despite building a tolerance/having withdrawal

What is the difference between tolerance and addiction? What is withdrawal?

Tolerance is when the brain adapts to the drug, which requires larger doses to get the same effect. Addiction is when people can't resist, even if it could lead to harm.
Withdrawal is any feelings of discomfort someone has after quitting a drug

Depressants

Drugs that calm the body/slow you down. Alcohol reduces inhibitions, slows neural processing and can disrupt memory.

Opiates

Slows down natural functioning and reduces pain sensations. Really easy to build a tolerance too. Heroin leads to intense withdrawals and a big crash afterwards. Disrupts mental chemical balance. Medically prescribed painkillers: Breathing slows, can stop endorphin production entirely if used for too long, easy to build a tolerance.

Stimulants

Excites neural activity and speeds up bodily functions. Results in dilated pupils, increased heart/breathing rate and higher blood sugar levels. Caffeine increases bodily activity slightly for a short time. Cocaine triggers the release of powerful neurotransmitters, can cause heart attack. Ecstasy is a more powerful stimulant and may cause mild hallucinations

Hallucinogens

Distort perceptions and evokes images w/o seeing them. Can cause delusions. LSD triggers euphoria, panic, and distortions. Marijuana impairs motor coordination, reaction time, and reduces cognitive ability.

Function of the nervous system

A network that takes information from outside, makes a decision, and the sends that info back to the muscles.

Nervous system

Peripheral: Sensory/motor neurons connected to CNS
Central: Spine and brain, decision making
Autonomic: Controls organs that function involuntary (breathing, digestion)
Somatic: Everything else that is voluntary (thinking, movement of muscles
Sympathetic: Arousing the fight or flight reflex. Reduced digestion, faster heart rate, faster breathing etc.
Parasympathetic: Resting system, opposite of sympathetic.

Sensory neurons

Activated by sensory input from the environment. Carries info from sensory muscles to CNS.

Motor neurons

Carries info away from CNS and towards muscles.

Interneurons

Located between sensory and motor neurons. Acts as a relay for info going from CNS/PNS

Reflex Arc:

Not all incoming messages go to brain
Some travel to the spinal cord and back again if it important (like a pain signal)
Skips going to brain because its faster

Endocrine system

releases hormones into the bloodstream. Slower acting than neurvous system, but longer lasting. Made up of glands that release chemicals.

Hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues. Slower than neurotransmitters

Adrenaline

Hormone released in response to high stress situations (Fight or flight response)

Leptin

Hormone released by fat cells that regulate appetite (Says when you are full)

Ghrelin

Secreted by the stomach that tells the brain "I'm hungry"

Melatonin

Produced by the pineal gland in response to darkness, tells the body to go to sleep, regulates the sleep-wake cycle

Oxytocin

Love hormone released in response to positive social interactions and bonding. Leads to attachment

pituitary gland

The most influential gland in the endocrine glandular system. It releases hormones for human growth, oxytocin, and directs other endocrine glands to release their hormones.