AP Psych Unit 1-A: Biological Bases of Behavior

Nature

how much of human experience is biological/genetic

Nurture

how much of human experience is built by our environment

Twin Studies

comparing MZ and DZ twins

Monozygotic (identical) twins

a fertilized egg splits into two; twins share 100% of genes

Dizygotic (fraternal) twins

two eggs are fertilized by two different sperm cells; share 50% of genes (no more similar than any pair of siblings)

Adoption Studies

comparing adoptive children and their biological and adoptive families; investigate role of nurture

Family Studies

Comparison of parents, their children, and their sibling; investigate role of genetics

Neurons

neural cells that transmit signals throughout the body; collect, process, and respond to info

Glial Cells

non-neuronal cells in the nervous system that support neuron structure and function

Reflex Arc

simple neural circuits; input, integration, output; bypass brain for quicker reaction time

Sensory neurons

Afferent neurons, detect sensory information like needle on skin

Motor neurons

efferent neurons, output, muscle or gland activity

S.A.M.E

Sensory=Afferent; Motor=Efferent

Interneurons

integrate information, communicate with (or bypass) brain

Dendrites

receive messages from other cells

Soma (Cell Body)

the cell’s life support center including the nucleus which contains DNA

Axon

Passes messages away from the cell body to other neurons, muscles, or glands

Myelin Sheath

Covers the axon of some neurons and helps speed neural impulse; the fatty tissue layer segmentally encasing the axons for insulation

Terminal Branches

form junctions with other cells

Action potential

an electrical charge that travels down a neuron (dendrite → terminal branches)

Resting potential

A neuron at rest has a voltage of approximately -65 mV

Threshold

minimum voltage needed to fire an action potential; if not strong enough, no signal is passed along

All-or-none response

If threshold is met neuron fires a full response; if threshold is not met no response

Depolarization

increasing membrane potential (mV); neuron becomes positive; Na+ in (+40 mV)

Repolarization

Decreasing membrane potential; neuron returns to negative voltage; K+ out

Hyperpolarization

overshoots resting potential, neuron becomes negative; lag on K+ channels

Refractory period

created by hyperpolarization; brief period which another action potential cannot be produced in that region; ensures signal in one direction

Myelination

Speeds things up; messages passed quicker

Multiple sclerosis (MS)

damaged myelin → increased reaction time; auto immune disorder in which immune cells attack and destroy myelin on nerve cells in the central nervous system

Synapse

the space between adjacent neurons; chemical signal is passed across to the next neurons

Neurotransmitters

chemicals in synaptic vesicles; release triggered by action potential

Diffusion

neurotransmitters simply diffuse out of the synapse

Reuptake

Neurotransmitters are taken back up by a neuron recycling channel

Digestion

broken down by enzymes and no longer binding to postsynaptic neuron

Excitatory NT

depolarizes neuron; encourages an action potential; membrane voltage becomes more positive; approaches threshold → more likely to fire

Inhibitory NT

further polarizes neuron; discourages an action potential; membrane voltage becomes more negative; moves away from threshold

Acetylcholine

enables skeletal muscle movement; enhances learning, memory, and attention

Norepinephrine/noradrenaline

Influences alertness and arousal; active in the fight or flight response

Serotonin

affects mood, hunger, sleep, and psychological arousal

Dopamine

Reward pathways; enhances muscle movement, emotion, attention, and more

GABA

major inhibitory neurotransmitter; important role in learning and memory

Glutamate

major excitatory neurotransmitter; important role in learning and memory

Endorphins

Natural pain relivers and mood boosters; modulate pain response and replace with pleasure (ex. runners high)

Substance p

Role in pain perception and activating immune response

Myasthenia gravis

Chemical signal impacted; causes muscle weakness and fatigue; antibodies block receptors → neuron to neuron communication; auto immune disease where antibodies block acetylcholine receptors

Endocrine system

a collection of glands that produce hormones; chemicals that are released directly into the circulatory system (often activated by nervous system)

Adrenaline

Adrenal glands (pancreas: regulate blood glucose level) cortisol; fight or flight response horomones

Oxytocin

Pitutary gland which can release into the blood stream; love hormone, facilitate childbirth, sexual excitement

Drugs

interrupts neurons

Narcotics (opiates)

Binds endorphin receptors → pain relief euphoria/dopamine release (ex. opium, morphine, heroin)

Stimulants

Stimulate neural activity; excitatory NT (ex. caffeine, nicotine, methamphetamine, cocaine)

Depressants

Depress neural activity → can stimulate the release of GABA (inhibitory NT) (ex. Alcohol, barbiturates)

Hallucinogens

Distorts sensory perception or cognition (ex. LSD/Acid, MDMA/Ecstasy/Molly, Marijuana/THC)

Agonists

A drug molecule that binds receptor sites and increases a neurotransmitter’s action (ex. marijuana)

Antagonist

A drug molecule that binds receptor sites and inhibits or blocks a neurotransmitter’s action (ex. pain killer and caffeine)

Reuptake Inhibitors

a drug molecule that prevents reuptake of a neurotransmitter; increases NT’s action (ex. cocaine and antidepressants)

Tolerance

drug’s effect lessens after repeated use → takes larger doses to feel high

Dependence

Physiological and/or psychological need to use a drug

Addiction

compulsive drug craving and use, despite adverse consequences

Withdrawal

the discomfort and distress that follow discontinued use of an addictive drug

Soma/Cell Body

1

Terminal Branches

2

Dendrites

3

Axon

4

Myelin

5

Repolarization

1

Depolarization

2

Hyperpolarization

3

Resting potential

4

Threshold

5

Central  Nervous System

Brain spinal cord; integrate signals from various regions of the body, includes interneurons

Peripheral Nervous System

Outside of brain and spinal cord; carries info into/out of the CNS; Afferent/efferent neurons

Somatic

controls the body’s skeletal movement; voluntary control

Autonomic

controls the glands and muscles of internal organs; operates automatically

Sympathetic

Fight or flight; arouses the body, mobilizing it’s energy

Parasympathetic

Rest and digest; calms the body, conserving it’s energy

Lesions

areas of the brain tissue that are damaged or deteriorating; can be natural

CAT/CT Scan

computerized tomography; uses a series of x-rays (radia

MRI

uses magnetic fields to visualize the brain’s structure; expensive and detailed

EEG

measures electrical activity in the brain; fast but not location specific

fMRI

measurement of oxygen use by brain cells; visualize what areas of the brain are involved in different tasks

PET

monitor circulation of radioactive tracers; visualize glucose, metabolism, and oxygen/blood flow

Brainstem (reptilian)

Medulla oblongata, Reticular activating system, cerebellum

Medulla oblongata

control of heart rate and breathing

Reticular activating system

some motor function, breathing, eye movement, arousal, sleep/wake cycle

Cerebellum

coordinates voluntary movement and balance

Limbic system (feeling)

Thalamus, Amygdala, Hippocampus, Hypothalamus, Pituitary gland

Thalamus

Sensory relay station; directs sensory info (touch, vison, hearing, taste) to other parts of the brain

Amygdala

Response to strong emotion trending negatively (ex. fear)

Hippocampus

encoding and processing memory

Hypothalamus

governs pituitary gland; feeding, fighting, fleeting, “mating”

Pituitary gland

Regulated by hippocampus; releases hormones (ex. appetite)

Cerebral cortex (neocortex) 

Frontal lobe, Parietal lobe, temporal lobe, occipital lobe

Frontal lobe

higher order thinking, language processing, judgment, and decision making

Motor cortex

initiates motor movement; within frontal lobe

Broca’s area/aphasia

language center located in the left frontal lobe, involved in expressive language (speech)

Parietal lobe

processes sensory input for touch and body position 

Somatosensory

touch sensitivity

Temporal lobe

auditory information and linguistic processing; primarily from opposite ear

Wernicke’s area/aphasia

language center located in the left temporal lobe; involved in language comprehension/coherence