ap psych unit 2

modules 9-18

neuron

a nerve cell; basic building block of the nervous system

dendrite

a neuron’s often bushy, branching extensions that receive and integrate messages, conducting impulses toward the body

axon

the neuron extension that passes messages through its branches to other neurons or to muscles or glands

myelin sheath

a fatty tissue layer segmentally encasing axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next

glial cells

cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory

cell body

part of a neuron that contains the nucleus; the cell’s life-support center

action potential

a neural impulse; a brief electrical charge that travels down an axon

threshold

the level of stimulation required to trigger a neural impulse

refractory period

in neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state

all-or-none response

a neuron’s reaction of either firing (with full-strength response) or not firing

synapse

junction between axon tip of the sending neuron and the dendrite or cell body of the receiving neuron; tiny cap at this junction is called synaptic gap or synaptic cleft

neurotransmitters

chemical messengers that cross the synaptic gap between neurons; when released by the sending neuron, they travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse

reuptake

a neurotransmitter’s reabsorption by the sending neuron

acetylcholine

enables muscle action, learning, and memory; alzheimer’s

dopamine

influences movement, learning, attention, and emotion; oversupply linked to schizophrenia, undersupply linked to tremors and parkinson’s

serotonin

affects mood, hunger, sleep and arousal; undersupply linked to depression

norepinephrine

helps control alertness and arousal; undersupply can depress mood

GABA

major inhibitory neurotransmitter; undersupply linked to seizures, tremors, and insomnia

glutamate

major excitatory neurotransmitter involved in memory; oversupply can overstimulate the brain and produce migraines or seizures

endorphins

neurotransmitter that influences the perception of pain and pleasure; oversupply with opiate drugs can suppress the body’s natural endorphin supply

agonist

molecule that increases a neurotransmitter’s action

antagonist

molecule that inhibits/blocks a neurotransmitter’s action

nervous system

the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems

central nervous system

the brain and spinal cord

peripheral nervous system

the sensory and motor neurons that connect the central nervous system to the rest of the body

nerves

bundles axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs

sensory (afferent) neurons

neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord

motor (efferent) neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

interneurons

neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs

somatic nervous system

the division of the peripheral nervous system that controls the body’s skeletal muscles

autonomic nervous system

part of the peripheral nervous system that controls the glands and muscles of the internal organs (e.g. heart); its sympathetic division arouses, parasympathetic division calms

sympathetic nervous system

division of the ANS that arouses the body, mobilizing its energy

parasympathetic nervous system

division of the ANS that calms the body, conserving its energy

reflex

a simple, automatic response to a sensory stimulus, such as the knee-jerk response

endocrine system

the body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream

hormones

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

adrenal glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress

pituitary gland

the endocrine system’s most influential gland; under the influence of the hypothalamus, it regulates growth and controls other endocrine glands

lesion

tissue destruction

EEG

an amplified recording of the waves of electrical activity sweeping across the brain’s surface; waves are measured by electrodes placed on scalp

MEG

brain imaging technique that measures magnetic fields from the brain’s natural electrical activity

CT scan

series of x-rays taken from different angles and combined by computer into a composite representation of a slice of the brain’s structure

PET scan

visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

MRI

technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissues; show brain anatomy

fMRI

technique for revealing bloodflow and brain activity by comparing successive MRI scans; show brain function as well as structure

brainstem

oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; responsible for automatic survival functions

medulla

base of the brainstem; controls heartbeat and breathing

thalamus

brain’s sensory control center located on top of the brainstem; directs messages to sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

reticular formation

nerve network that travels through the brainstem into the thalamus and plays an important role in controlling arousal

cerebellum

“little brain” at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory

limbic system

neural system below the cerebral hemispheres; associated with emotions and drives

amygdala

two lima-bean-sized neural clusters in the limbic system; linked to emotion

hypothalamus

neural structure lying below the thalamus; directs several maintenance activities (eating, drinking, temp), helps govern the endocrine system via the pituitary gland, and linked to emotion and reward

hippocampus

neural center located in limbic system; helps process for storage explicit (conscious) memories of facts and events

cerebral cortex

intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information-processing center

frontal lobes

portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgements

parietal lobes

portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position

occipital lobes

portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields

temporal lobes

portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear

motor cortex

area at the rear of the frontal lobes that controls voluntary movements

somatosensory cortex

area at the front of the parietal lobes that registers and processes body touch and movement sensations

association areas

areas of the cerebral cortex that are not involved in primary motor or sensory functions; involved in higher mental functions like learning, remembering, thinking, speaking

plasticity

brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience

neurogenesis

formation of new neurons

corpus callosum

large band of neural fibers connecting the two brain hemispheres and carrying messages between them

split brain

condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers connecting them

consciousness

our subjective awareness of ourselves and our environment

cognitive neuroscience

interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memoroy, and language)

dual processing

principle that information is often simultaneously processed on separate conscious and unconscious tracks

blindsight

condition where a person can respond to a visual stimulus without consciously experiencing it

parallel processing

processing many aspects of a problem simultaneously; generally used to process well-learned information or to solve easy problems

sequential processing

processing one aspect of a problem at a time; generally used to process new information or to solve difficult problems

behavior genetics

study of the relative power and limits of genetic and environmental influences on behavior

heredity

the genetic transfer of characteristics from parents to offspring

environment

every non-genetic influence, from prenatal nutrition to the people and things around us

chromosomes

threadlike structures made of DNA molecules that contain the genes

DNA

complex molecule containing the genetic information that makes up chromsomes

genes

biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins

genome

complete instructions for making an organism, consisting of all the genetic material in that organism’s chromosomes

identical (monozygotic) twins

develop from a single fertilized egg that splits in two, creating two genetically identical organisms

fraternal (dizygotic) twins

develop from separate fertilized eggs; genetically no closer than ordinary siblings but share a prenatal environment

heritability

proportion of variation among individuals in a group that we can attribute to genes; can vary depending on the range of populations and environments studies

interaction

interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity)

molecular genetics

subfield of biology that studies the molecular structure and function of genes

molecular behavior genetics

the study of how the structure and function of genes interact with our environment to influence behavior

epigenetics

“above” or “in addition to” genetics; the study of environmental influences on gene expression that occur without a DNA change

evolutionary psychology

the study of the evolution of behavior and the mind, using principles of natural selection

natural selection

the principle that inherited traits that better enable an organism to survive and reproduce in a particular environment will most likely be passed on

mutation

a random error in gene replication that leads to a change

sleep

periodic, natural loss of consciousness

circadian rhythm

our biological clock; regular bodily rhythms that occur on a 24 hour cycle

REM sleep

rapid eye movement sleep; a recurring sleep stage during which vivid dreams commonly occur; muscles are relaxed but other body systems are active

alpha waves

relatively slow brain waves of a relaxed, awake state

NREM sleep

non-rapid eye movement sleep encompasses all sleep stages except for REM sleep

hallucinations

false sensory experiences such as seeing something in the absence of an external visual stimulus

hypnagogic sensations

bizarre experiences, such as jerking or a feeling of falling or floating weightlessly, while transitioning to sleep

delta waves

large, slow brain waves associated with the deep sleep of NREM-3

suprachiasmatic nucleus

pair of cell clusters in the hypothalamus that controls circadian rhythm; in response to light, causes pineal gland to adjust melatonin production and modify our feelings of sleepiness

insomnia

recurring problems in falling or staying asleep

narcolepsy

sleep disorder characterized by uncontrollable sleep attacks; sufferer may lapse directly into REM sleep often at inopportune times