AP Psych

Biological psychology: the scientific study of the links between biological (genetic, neural, hormonal) and psychological processes. (Some biological psychologists call themselves behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists

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

Dendrites: a neuron's bushy, branching extensions that receive messages and conduct 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 sausage-like node to the next

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

Refractory period: a period of inactivity after a neuron has fired

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. 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, neurotransmitters transmitters 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 opiate-like neurotransmitters linked to pain control and to pleasure

Agonist: a molecule that, by binding to a receptor site, stimulates a response

Antagonist: a molecule that, by binding to a receptor site, inhibits or blocks a response

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 the 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

Sensory (afferent) neurons: neurons that carry incoming information from the sensory receptors to the brain and the 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 that communicate internally and intervene between the sensory inputs and motor outputs

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 (ANS): the part of the peripheral nervous system that controls the glands and the muscle of the internal organs (such as the heart). Its sympathetic division arouses, its parasympathetic division calms

Sympathetic nervous system: the division of 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 gland 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): 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 (computer tomography) 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 (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. MRI scans show brain anatomy

fMRI (functional MRI): a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show how brain function as well as its structure

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

Thalamus: the brain’s sensory control center, 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

Reticular formation: a nerve network that travels through the brainstem and thalamus and plays an important role 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 hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives

Amygdala: 2 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; they may also play a role in learning and thinking

Frontal lobes: portion of the cerebral cortex lying just behind the forehead, involved in speaking and muscle movements and in making plans and judgment

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 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: 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 influence on behavior

Environment: every external 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 chromosomes

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

Genome: the complete instructions for making an organism, consisting of all the genetic material in that organisms chromosomes

Identical twins(monozygotic): twins who develop from a single fertilized egg that splits in two, creating 2 genetically identical organisms

Fraternal twins(dizygotic): twins who develop from separate fertilized eggs. They are genetically no closer than brothers and sisters, but they share a fetal environment

Molecular genetics: the subfield of biology that studies the molecular structure and function of genes

Heritability: the properties of variation among individuals that we can attribute to genes. The heritability 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)

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