Psych Unit 2 final study guide

Myelin sheath

* Fatty substance axons are wrapped in 


* Increases speed of action potential (faster communication)

Dendrites

Branch like projects that receive messages from other neurons and send them to the neuron

Cell body (soma)

* Made up of nucleus that determines when neuron has reached threshold to fire


* Caries basic metabolic functions of neuron

Axon 

* Tail of neuron where electric signals conducted


* Electric impulses will carry messages to other neurons

Axon terminals

* Knobs at end of each axon that house neurotransmitters 


* During action potential, neurotransmitters released into synapse

Synapse

Gap between axon terminals of sending (presynaptic ) neuron and dendrites of receiving (postsynaptic) neuron

**Resting state/resting potential**

* -70 millivolts inside cell 


* Negative charge -> potassium (with chloride ions) inside , big amount of sodium ions outside

Firing threshold

Level necessary for neuron to fire

Depolarization

* Positively charged sodium ions rush the cell


* Postassium ions flow out 
* Temporarily leaves positive charge on inside -> causes action potential 

Action potential 

message/electrical impulse moving down axon of the neuron 

All-or-non law

A neuron can never fire harder or stronger b/c it either fires completely or not at all

Communication between neurons

* Electric signal reaches end of axon -> causes release of neurotransmitter


* When correct neurotransmitter arrives at receptor site of receiving neuron, neurotransmitter will bind to specific receptor site 

Refractory period

* After neuron fires its electrical signal has period when cell can’t fire again


* Allows neurons to reset (repolarization)

Reuptake

When neurotransmitters left in synapse (not broken down) return to vesicles on sending axon terminal 

Mirror neurons

When we see someone else do something, mirror neuron pathways fire as if we were doing it ourself

afferent/sensory neurons

Carry messages from sensory organs (skin, eyes, ears) to CNS

Interneurons

Messages heading towards brain/spinal cord are transferred to interneurons for processing

efferent/motor neurons

Carry messages from CNS to muscles and glands

Excitation 

Stimulates firing of messages

Inhibition

Restricts firing of messages

Agonists 

Drug that enhances action of neurotransmitter

Antagonists

Drug that inhibits action of neurotransmitor

Glutamate

* Primary excitatory neurotransmitter 


* Too high -> epilepsy, alzheimer’s

GABA

Primary inhibitory neurotransmitter

Endorphins

* Pain relief 


* Inhibitory 

Norepinephrine

* Alertness and arousal 


* Excitatory 
* Too low -> depression

Acetylcholine

* Learning, memory, voluntary muscle movements


* Too low -> Alzheimers/dementia 

Serotonin 

* Mood, appetite, sleep 


* Too low -> depression, anxiety 

Dopamine

* Pleasure, muscular control, learning attention 


* Too high -> schizophrenia 
* Too low -> parkinson’s 

The reflex arc

* Reflexes controlled by spinal cord


* Can act on impulse before impulse reaches your brain 

Glial cells 

Support cells of message-sending neurons 

The lock and key analogy 

A neurotransmitter will only bind to specific receptor 

LTP

* How new neural networks are formed 


* Triggering the same sequence of neurons over and over again creates faster more efficient pathways

Phineas Gage

* Iron rod driven through his skull


* Front lobes severed from limbic system -> became high impulsive and emotional

The frontal lobe

* Prefrontal - planning, judgement, decision making


* Motor cortex - voluntary muscle movement
* Broca’s area -> speech production 

Parietal cortex

* Governs incoming sensory info


* Somatosensory cortex - evaluates that info from skin 

Occipital lobe

Processing of visual info

Temporal lobe

* processes info from ears


* Essential to sense of smell
* Wernike’s area -> speech comprehension

Medulla 

Breathing, swallowing, heart rate, digestion

Pons 

Sleep and dreaming

reticular formation 

Alertness and attention to incoming sitmuli

Cerebellum 

Balance, coordination, smooth muscle moovements

The somatic system

Voluntary movements

The autonomic system

Involuntary functions

Sympathetic 

* Arouses body to expand energy 


* Flight or fight

Parasympathetic 

* Returns body to resting state (maintain homeostasis)


* Breath + heart rate down, increases saliva + digestion 

The limbic system

thalamus, hypothalamus, amygdala, hippocampus

The thalamus

Sorts and relays sensory info 

The hypothalamus

Regulate fighting, feeding, flighting, mating 

The amygdala 

Emotional responses

The hippocampus

Formation of new memories + transfer from short term to long term 

Neuroplasticity 

Brain able to wire and rewire its synaptic connections

neurogenesis

Process by which brain creates new neurons throughout someone’s life 

Lateralization

* Two hemispheres have specialized functions


* Right -> visual, spatial, artistic, musical
* Left -> mathematical, logical, analytical, linguistic

Localization

Belief that specific abilities are held in only one area of the brain 

EEG

* Brain function


* Detects electrical activity (neurons firing)

CT

* Brain structure


* x-ray

MRI

* Brain structure


* Magnetic + radio frequencies 
* Gray matter - cell bodies of neurons
* White matter - myelin sheath axons 

fMRI

* Brain function 


* While patient is thinking/doing task -> can see what parts of brain have increased oxygen/blood flow 

PET

* Brain function


* Injection of radioactive substance
* Trace metabolism of glucose
* See where glucose flows as patient performs task 

Pituitary gland

* “Master gland”


* Oxytocin (bonding - parent child connection)
* Human growth hormone

Pineal gland 

Secretes sleep by inducing melatonin

Thyroid and parathyroid glands

Growth + metabolism 

Adrenals 

Govern fight or flight response (secretion of adrenaline/epinephrine and cortisol)

Pancreas

Secretes Insulin

Ovaries

* Produce estrogen -> regulates menstrual cycle 


* Development of primary sex characteristics at puberty

testes 

* Produce testosterone -> high levels = high aggression 


* Development of primary sex characteristics at puberty 

Genotype

One’s genetic makeup

Genetic predisposition

Human’s born with tendency towards certain behavior

Epigenetics 

Change in gene expression that do no cause change in gene itself

Phenotype

What you see when you look at person (interaction of genetics + environment)

Circadian rhythms 

* Activity in suprachiasmatic nucleus (part of hypothalamus) governs internal clock


* Influences pineal gland by creating mealton
* During evening sends signals to increase production (during morning almost non-existent)

Theta waves

light sleep

alpha waves

resting state (almost asleep)

delta waves

deep sleep

beta waves

waking states

NREM- 1

* Light sleep characterized by theta waves


* Sometimes feel like falling or floating

NREM-2

* Largest percetnage of sleep


* Theta waves
* Sleep spindiles - rapid electrical activity
* K-complexes - high amplitude slow brain ways

NREM-3

* Deepest stage of sleep (delta waves)


* Relaxed - breath, temp, heart rate decreases

REM

* Brain is active + heart rate and blood pressure are elevated


* Muscles essentially paralized

Sleep paralysis 

Motor cortex actively sends messages, but brainstem stops those messages resulting in inability to move during REM sleep 

Restorative theory

To rejuvenate ourselves

adaptive/evolutionary theory

Generally been safer and more functional to sleep at night

REM rebound

* Someone intentionally awakened at onset of REM period 


* Next night have longer REM

Sleep and age

* Babies spend twice as much time in REM


* Having new experiences need more sleep for memory consoldiation

Insomnia 

Inability to fall asleep or stay asleep

Hypersomnia

Excessive sleepiness

Narcolepsy

Sudden involuntary change from alert state to sleep state

Apnea

Person frequently stops breathing during night

Night terrors

Sweating, increased heart rate, little recall of event in morning (report terrifying experience and believe its real)

Somnambulism

Sleepwalking (NREM-3)

Somniloquy

Sleep talking without remembering (NREM-3)

REM sleep behavior disorder

* Sleeper not paralyzed during REM


* Can act out dreams (dangerous)

Information processing theory (Dream)

Info learned during day transferred into memories as we dream

Activation-synthesis theory (dream)

* Because brain is active during REM, brain regions involved in memory, perception, and emotion activated


* Try to make sense of them by creating story

Freudian psychoanalytic theory

Unconscious controls content of dreams

Lucid dreaming

When you’re dreaming and have sense you were in a dream

Nightmares vs night terrors 

* Nightmares occurs in REM sleep 


* REM night terrors occur in NREM

Recurring dream themes 

* Unresolved difficulties or conflicts


* Presence of anxiety and depression

Stimulants

* Activate nervous system -+ increase levels of activity 


* Nicotine, caffeine 
* Cocain, amphetamines increase dopamine + norepineprhine activity