Unit 2 Part 1 Myers' Psychology for the AP Course

Neuron

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

Sensory (afferent) Neurons

Neurons that carry incoming information from the sense receptors to the central nervous system.

Motor (efferent) Neurons

Neurons that carry outgoing information from the central nervous system to the muscles and glands.

Interneurons

CNS neurons that internally communicate 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

Layer of fatty tissue segmentally encasing the fibers of many neurons, speeds up 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 cleft.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons.

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--all the nerve cells of the peripheral and central nervous systems.

Central Nervous System

The brain and the spinal cord.

Peripheral Nervous System

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.

Somatic Nervous System

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

Autonomic Nervous System

The part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands.

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, inborn 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, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another.

Adrenal Glands

A pair of endocrine glands just above the kidneys. They secrete the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline), which help to 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.

Lesion

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

Electroencephalogram (EEG)

Amplified tracing of brain activity--electrodes positioned over the scalp transmit signals about the brain's electrical activity to an electroencephalograph machine.

CT Computer Tomography

A series of x-rays images are taken in multiple views (especially cross section).

PET (Positron 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)

Technique that uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of soft tissue; allows us to see structures within the brain

fMRI (Functional Magnetic Resonance Imaging)

Technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. MRI scans show brain anatomy; fMRI 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; the brainstem 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" attached to the rear of the brainstem; it helps coordinate voluntary movement and balance.

Limbic System

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 that are components of the limbic system and are linked to emotion.

Hypothalamus

Neural structure lying below the thalamus; directs eating, drinking, body temperature; helps govern the endocrine system via the pituitary gland, and is linked to emotion.

Cerebral Cortex

The fabric of interconnecting cells that blankets the brain hemispheres; the brain's center for information processing and control.

Glial Cells

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

Frontal Lobes

Portion of the cerebral cortex 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; includes the sensory cortex.

Occipital Lobes

Portion of the cerebral cortex at the back of the head; includes the visual areas, which receive visual information from the opposite visual field.

Temporal Lobes

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

Motor Cortex

An area of the brain, near the rear of the frontal lobes, that controls voluntary movement.

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; 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

Condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers (mainly those of the corpus callosum) between them.

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 come from one fertilized egg; twins having the same heredity.

Fraternal Twins

Twins who come from two different eggs fertilized by two different sperm.

Heritability

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

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.

Mutation

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

Cell Body

The part of the neuron that contains the nucleus, which directs the manufacture of substances that the neuron needs for growth and maintenance.

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

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 (conscious) memories of facts and events for storage.

Consciousness

our subjective 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

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; generally used to process well-learned information or easy to solve problems..

Sequential Processing

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

Heredity

the genetic transfer of characteristics from parents to offspring

Molecular Behavioral Genetics

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

Epigenetics

"above" or "in addition to" (epi) genetics; the study of environmental influences on gene expression that occur without 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 (in competition with other trait variations) most likely be passed on to succeeding generations.

Social Script

culturally modeled guide for how to act in various situations

Broca's Area

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

Wiernicke's Area

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