ap psych brain and bio

biological psychology

A branch of psychology concerned with the links between biology and behavior.

neuron

A nerve cell; the basic building block of the nervous system.

sensory neurons

Neurons that carry incoming information from the sensory receptors to the brain and spinal cord.

motor 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 that communicate internally and intervene between the sensory inputs and motor outputs.

dendrite

The bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body.

axon

The extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands.

myelin sheath

A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

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.

synapse

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

neurotransmitters

Chemical messengers that cross the synaptic gaps 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.

endorphins

"Morphine within"—natural, opiatelike neurotransmitters linked to pain control and to pleasure.

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 (CNS)

The brain and spinal cord.

peripheral nervous system (PNS)

The sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

nerves

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

somatic nervous system

The division of the peripheral nervous system that controls the body's skeletal muscles. Also called the skeletal nervous system.

autonomic nervous system

The part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.

sympathetic nervous system

The division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.

parasympathetic nervous system

The division of the autonomic 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, the pituitary regulates growth and controls other endocrine glands.

electroencephalogram (EEG)

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

CT (computed tomography) scan

A series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body. Also called CAT scan.

PET (positron emission tomography) scan

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. They scans show brain anatomy.

fMRI (functional MRI)

A technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. These scans show brain function.

brainstem

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

medulla

The base of the brainstem; controls heartbeat and breathing.

reticular formation

A nerve network in the brainstem that plays an important role in controlling arousal.

thalamus

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

cerebellum

The "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance.

limbic system

Doughnut-shaped neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.

amygdala

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

hypothalamus

A neural structure lying below (hypo) the thalamus; 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 covering the cerebral hemispheres; the body's ultimate control and information-processing center.

glial cells (glia)

Cells in the nervous system that support, nourish, and protect neurons.

frontal lobes

Portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments.

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

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

association areas

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.

aphasia

Impairment of language, usually caused by left hemisphere damage either to Broca's area (impairing speaking) or to Wernicke's area (impairing understanding).

Broca's area

Controls language expression—an area, usually in the left frontal lobe, that directs the muscle movements involved in speech.

Wernicke's area

Controls language reception—a brain area involved in language comprehension and expression; usually in the left temporal lobe.

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 awareness of ourselves and our environment.

cognitive neuroscience

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

dual processing

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

behavior genetics

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

environment

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

chromosomes

Threadlike structures made of DNA molecules that contain the genes.

DNA (deoxyribonucleic acid)

A complex molecule containing the genetic information that makes up the chromosomes.

genes

The biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing a protein.

genome

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

identical twins

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

fraternal twins

Twins who develop from separate fertilized eggs. They are genetically no closer than brothers and sisters, but they share a fetal environment.

heritability

The proportion of variation among individuals that we can attribute to genes. This 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).

molecular genetics

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

evolutionary psychology

The study of the roots of behavior and mental processes using the principles of natural selection.

natural selection

The principle that, among the range of inherited trait variations, those contributing to reproduction and survival will most likely be passed on to succeeding generations.

mutation

A random error in gene replication that leads to a change.

Cell body

part of a nerve cell that contains the nucleus

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 a full-strength response) or not firing.

Agonist

a molecule that increases a neurotransmitter's action

Antagonist

a molecule that inhibits or blocks a neurotransmitter's action

Reflex

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

Lesion

tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue

MEG (magnetoencephalography)

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

Hippocampus

A neural center located in the limbic system that helps process explicit memories for storage.

somatosensory cortex

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

Conciousness

our awareness of ourselves and our environment

Blindsight

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

parallel processing

the processing of many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision. Contrasts with the step-by-step (serial) processing of most computers and of conscious problem solving.

sequential processing

the processing of one aspect of a problem at a time; used when we focus attention on new or complex tasks

Heredity

the genetic transmission of characteristics from parents to their offspring

Epigenetics

the study of environmental influences on gene expression that occur without a DNA change

pineal gland

produces melatonin

thyroid gland

produces hormones that regulate metabolism, body heat, and bone growth

Parathyroid Gland

Controls the body's calcium level

Melatonin

hormone that is produced by the pineal gland in humans and animals and regulates sleep and wakefulness

Dopamine

Neurotransmitter that influences movement, learning, attention and emotion.

Serotonin

Neurotransmitter that influences mood, hunger, sleep, and arousal

Norepinephrine

neurotransmitter that helps control alertness and arousal

Glutamate

A major excitatory neurotransmitter; involved in memory

Endorphins

Neurotransmitters that influence the perception of pain or pleasure

Pons

A brain structure that relays information from the cerebellum to the rest of the brain

Acetylcholine

A neurotransmitter that enables learning and memory and also triggers muscle contraction

social script

culturally modeled guide for how to act in various situations