AP PSYCH - NEUROSCIENCE (god help us all)

neuroscience

study of structure and the function of the nervous system

what is a nerve

made up of billions of neurons

peripheral nervous system

nerves that run from the spinal cord through the body. connect to muscles and glans. receives sensations (except smell).

central nervous system

spinal cord and brain

what does the spinal cord recieve

sensory signals

reflexes

if a signal is life or death it is a reflex. a reflex is an automatic action that requires no thought.

if the signal requires cognition or thinking, it travels to...

the brain

if a motor action is required through reflex or cognition, it is relayed back through the....

peripheral nervous system

if sensory neurons...they travel from the sensory organs to the

central nervous system

two divisions of the motor aspect of the PNS are...

somatic and autonomic

somatic ns

voluntary action - one we chose to do through cognition

somatic ns communicates through...

motor neurons

motor cortex

in the frontal lobe of the brain...communicates the voluntary action we want to take

autonomic ns

involuntary actions - muscles and gland movements you can't control

brain stem

regulates heartbeat and breathing - involuntary actions

two parts of autonomic ns

sympathetic and parasympathetic

sympathetic ns

prepares us for fight or flight

what does sympathetic ns do:

increases everything for survival

what does the sympathetic ns response not increase:

bladder contracts, digestion slows

parasympathetic ns

paramedics coming in to reverse everything aroused by sympathetic ns - back to homeostasis

neurotransmitters

how neurons communicate - chemical messengers

glial cells

provide nutrients and protection and waste transport - strengthen connections

how does nervous system work?

neurons receive sensory info (peripheral), carries it to CNS (brain, unless reflex), then neurons transmit info to muscles and the glands (motor cortex)

3 different types of neurons

sensory (afferent) PNS, interneurons CNS, motor (efferent) PNS

sensory neurons

PNS! found in skin cells and process somatosensation - balance, hearing, taste (the senses)

interneurons

CNS! percieve sensation coming and communicate with motor neurons for action. spinal cord to brain.

motor neurons

PNS! relay messages to muscles and glands

effectors

muscles and glands cells

myasthenia gravis

autoimmune disease the is due to weakness in voluntary muscles (somatic) due to error in how nerve signal is sent to the muscle (motor neurons). deterioration of ach neurons in the peripheral ns.

antibodies

alter or destroy neurotransmitter receptors at the muscle sites

nerve

bundle of neurons

dendrite

recieve incoming neurotransmitters

cell body

negative charge when at rest

excitatory neurotransmitters

if they attach to the dendrites, a rush of positive ions flood into the cell body

axon

conducting fiber that electricity fires through from the cell body

action potential

when the electric charge from the cell body reaches the axon - if it doesn't, electric charge dies

myelin sheath

bubbles of fatty tissue that protects the axon like insulation - made up of glial cells

what do neurons eat

glucose or sugar

multiple sclerosis

this degenerative disorder happens when myelin sheath breaks down

axon terminal/terminal buttons/branches

stores neurotransmitters

synapse

space between two neurons where the axon terminal releases neurotransmitters

what happens to neurotransmitters after they are released into synapse

some go back into the pre-synaptic neuron, some absorbed into post synaptic neuron

dendrites connect to the...

cell body of the next neuron

resting potential

if neuron is not firing it is at rest

at rest the cell body has a...

negative charge (-70mv)

outside the cell body has a

positive charge

inhibitory neurotransmitter

causes positive ions to be pumped out of the cell body

when the positive ions flood into the negative cell body (-70) it changes to the threshold which is...

-55mv

if the threshold isn't met.. nothing happens which is called

all or nothing response

reuptake

leftover neurotransmitters get reabsorbed by the pre synaptic axon terminal

what do problems with reuptake cause

schizophrenia

repolarization

after action potential. positive ions are pumped out of the cell body so the cell returns to resting state

refractory period

resting period after repolarization where the cell is resting and cant fire

hyperpolarization

during refractory period charge is less than -70mv , meaning it cannot fire.

acetylcholine neurotransmitter

enables muscle action, learning, and memory

alzheimers

caused by degeneration of ach neurons

dopamine

influences movement, learning, attention, and emotion. feel good neurotransmitter.

dopamine can cause addiction when...

dopamine reward pathway is activated

schizophrenia can occur when...(dopamine hypothesis)

there is too much dopamine due to problems with reuptake

parkinson's

deterioration or low levels of dopamine can cause parkinsons disease

serotonin

affects mood, hunger, sleep and arousal

too little serotonin

DEPRESSION AND ANXIETY (s)

norepinephrine

controls alertness and arousal.

too little norepinephrine

depression and anxiety

GABA

involved in sleep and relaxation.

gaba is what type of neurotransmitter

inhibitory - slows neural firing down

too little gaba causes:

anxiety disorders, insomnia, seizures -- epiliepsy

gulutamate

involved in learning and long term memory

glutamate is what type of neurotransmitter

excitatory - more neural firing

too much glutamate causes

seizures, migranes, and heart problems

MSG

preservative in many foods that contains glutamate

endorphins

serve as painkillers. produces when we exercise, eat spicy foods, are excited, or in love

opiates (dtaae)

drugs that act as endorphins

substance p

CNS. works with glutamate in transmission of pain.

substance p is an

excitatory neurotransmitter

where is substance p released

pns - at sensory nerves, causes inflammation

opioids block what?

block the release of substance p

agonist drugs

increase the amount of neurotransmitters at the synapse

agonist drugs do what

mimic neurotransmitters or they bind to the receptor sites and block reuptake, so more of the neurotransmitters build up.

most antidepressants are

agonist drugs- block reuptake

antagonist drugs

decrease the amount of neurotransmitters available in the synapse

antagonist drugs do what?

block release of neurotransmitters at terminal branches, or block receptor sites on the dendrite, decreasing amount of neurotransmitters being created

psychoactive drugs

chemical substances that alter perceptions - cause withdraw, tolerance, dependence

depressants

slow down central NS

what do depressants act as

GABA

depressants are

agonists

what do depressants to the body

supress rem sleep, decrease memory function

opiates

ACT as endorphins

examples of opiates

opium, heroin, and morphine

opiates are

stimulants! speed up the central nervous system

hallucinogens

cause an extrasensory experience!

marijuana (hallucinogens) are

agonists - block reuptake

what does the brain stem control

basic life functions - heart rate, breathing, conciousness

medulla oblongata

regulates heartbeat, breathing, and vomiting

if medulla is damaged

in can cause death

recticular activating system

nerve that connects spinal cord to the thalamus.

what does the recticular activating system do:

FILTERS!!! sleep wake cycle, voluntary movements, paralyzes the body in rem sleep, rapid eye movement

if the recticular activating system is injured

it may result in a coma

habituation

an organism's decreasing response to a stimulus with repeated exposure to it

thalamus (limbic system)

recieves info from all senses (except smell) - sends to proper cortex