AP Psych Unit 2

Neuron

a nerve cell; the basic building block of the nervous system

Dendrite

a neuron's often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell 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 the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next

Action potential

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

Refractory Period

(1) in neural processing, brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state. (2) in human sexuality, a resting period that occurs after orgasm, during which a person cannot achieve another orgasm

Threshold

the level of stimulation required to trigger a neural impulse

All-or-none response

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

Synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons. when released by the sending neuron, it travels 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

Endorphins

"morphine within" - natural, opiate-like neurotransmitters linked to pain control and to pleasure

Agonist

a molecule that increases a neurotransmitter's action

Antagonist

a molecule that inhibits or blocks a neurotransmitter's action

Nervous system

the body's speedy, electrochemical communication network, consisting of all the nerve cells

Central nervous system (CNS)

the brain and spinal cord

Peripheral nervous system (PNS)

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

Nerves

bundled 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 (skeletal nervous system)

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

Autonomic nervous system

automatically regulates the functions of the body system outside of voluntary control

Sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy

Parasympathetic nervous system

the division of the automatic nervous system 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. A naturally or experimentally caused destruction of brain tissue.

Electroencephalogram (EEG)

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

CT (computed tomography) (CAT scan)

a series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain's structure

PET (position emission tomography)

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

MRI (magnetic resonance imaging)

a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. Show brain anatomy

fMRI (functional MRI)

a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. Show brain function as well as structure

brainstem

the 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

the base of the brainstem; controls heartbeat and breathing

thalamus

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

reticular formation

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

cerebellum

the "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 (including the amygdala hypothalamus and hippocampus) located below the cerebral hemispheres; associated with emotions and drives

amygdala

two limba-bean-sized neural clusters in the limbic system; linked to emotion/processing fear and threatful stimuli

hypothalamus

it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

cerebral cortex

the intricate fabric of interconnected neural cells that covers the cerebral hemispheres

glial cells

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

frontal lobes

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

parietal lobes

the 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

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

temporal lobes

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

motor cortex

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

somatosensory cortex

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

association area

areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking

plasticity

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

neurogenesis

the formation of new neurons

Corpus callosum

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

Split brain

a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.

Consciousness

our subjective awareness of ourselves and our environment

Dual processing

the principle that information is often simultaneously process on separate conscious and un conscious tracks

Environment

every nongenetic influence, from prenatal nutrition to the people and things around us.

Chromosomes

threadlike structures made of DNA molecules that contain genes

DNA

a complex molecule containing the genetic information that makes up the chromosomes

Genes

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

Genome

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

Identical twins (monozygotic twins)

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

Fraternal twins (dizygotic twins)

develop from separate fertilized eggs. They are genetically no closer than ordinary siblings, but they share a prenatal environment

Molecular genetics

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

Heritability

the proportion of variation among individuals in a group that we can attribute to genes. The (term) of a trait may vary, depending on the range of populations and environments studied

Interaction

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

Epigenetic

"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 selection

Natural selection

the principle that inherited traits that better enable an organism to survive and reproduce in a particular environment will (in competition with other trait variations) most likely be passes on to succeeding generations

Mutation

a random error in gene replication that leads to a change

Resting potential

neuron waiting for signal; natural state

Depolarization

ions moving/mixing up, making it more prone to firing an action potential

Excitatory signal

the physical input to a neuron that signals it to activate

Inhibitory signal

when the transmission of neuron signals are prevented by neurotransmitters

Synaptic gap/cleft

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.

Acetylcholine (ACh)

a neurotransmitter involved in learning, memory, and muscle contraction

Dopamine

a neurotransmitter involved in mood, movement, attention, and learning

Serotonin

a neurotransmitter that regulates sleep, mood, appetite, and body temperature.

GABA (Gamma-aminobutyric acid)

the primary inhibitory neurotransmitter in the nervous system

Glutamate

the main excitatory neurotransmitter in the central nervous system; important for learning and memory

Spinal cord

carries messages from sensory receptors in the body to the CNS and more messages from the CNS to skeletal muscles

Epinephrine (adrenaline)

Secreted by the adrenal medulla; increases heart rate and blood pressure and dilates airways (sympathomimetic). It is part of the body's "fight or flight" reaction.

Norepinephrine (Noradrenalin)

helps control alertness and arousal

Pons

a part of your brainstem, a structure that links your brain to your spinal cord. relays sensory information to the cerebellum. regulates breathing, involved in the control of sleep cycles.

Hippocampus

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

Cerebrum

made up of two cerebral hemispheres that are separated by a large groove. The hemispheres can share information with each other through a thick bundle of nerves running between them called corpus callosum

Prefrontal cortex

primarily responsible for the "higher" brain functions of the frontal lobes, including decision-making, problem-solving, intelligence, and emotion regulation

Broca's cortex (Paul Broca)

helps control language expression - an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech

Wernicke's area (Carl Wernicke)

a brain area involved in language comprehension and expression; usually in the left temporal lobe

Roger Sperry

studies split brain patients; showed that left/right hemispheres have different functions

Michael Gazzaniga

1939-present; Field: cognition; studies the neural basis of mind with primary responsibility for initiation human split-brain research. In his subsequent work, he has made important advances in our understanding of functional lateralization in the brain and how the cerebral hemispheres communicate with each other

Consciousness

our subjective awareness of ourselves and our environment

Hypnosis

a social interaction in which one person suggests to another (the subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur.

Posthypnotic suggestion

a suggestion, made during a hypnosis session, to be carried out after the subject is no longer hypnotized; used by some clinicians to help control undesired symptoms and behaviors

Dissociation

a split in consciousness, which allows some thoughts and behaviors to occur simultaneously with others

Circadian rhythm

our biological clock; regulate bodily rhythms (for example, temperature and wakefulness) that occur on a 24-hour cycle

REM sleep (rapid eye movement)

a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active