AP Psychology Chapter 3

Dendrite

A branched fiber that extends outward from the main cell body and carries information into the neuron.

Hormone

A chemical messenger used by the endocrine system. Many hormones also serve as neurotransmitters.

Electroencephalogram (EEG)

A device for recording brain waves, typically by electrodes placed on the scalp. The record produced is known as an electroencephalogram.

somatic nervous system

A division of the peripheral nervous system that sends communications between the central nervous system and the internal organs and glands

DNA

A long, complex molecule that encodes genetic characteristics.

Interneuron

A nerve cell that relays messages between nerve cells, especially in the brain and spinal cord.

Neuroscience

A relatively new interdisciplinary field that focuses on the brain and its role in psychological processes.

Reflex

A simple, unlearned response triggered by stimuli- such as the knee-jerk reflex set off by tapping the tendon just below your kneecap.

Synaptic vesicle

A small "container" holding neurotransmitter molecules that then connects to the presynaptic membrane, releasing the neurotransmitter into the synapse.

peripheral nervous system

All parts of the nervous system lying outside the central nervous system. The perioheral nervous system includes the autonomic and somatic nervous system

Genotype

An organism's genetic makeup

Phenotype

An organism's observable physical characteristics.

Neural pathway

Bundle of nerve cells that follow generally the same route and employ the same neurotransmitter.

Neuron

Cell specialized to receive and transmit information to other cells in the body-also called a nerve cell. Bundles of many neurons are called nerves.

Glial cells

Cells that bind the neurons together. Glial cells also provide an insulating covering (the myelin sheath) of the axon for some neurons, which facilitates the electrical impulse.

Nuerotransmitters

Chemical messengers that relay neural messages across the synapse. Many neurotransmitters are also hormones

Agonist

Drug or other chemical that enhances or mimics the effects of neurotransmitters.

Antagonist

Drug or other chemical that inhibits the effects of neurotransmitters.

Axon

In a nerve cell, an extended fiber that conducts information from the soma to the terminal buttons. Information travels along the axon in the form of an electric charge called the action potential.

Motor neuron

Nerve cell that carries messages away from the central nervous system toward the muscles and glands. Also called an efferent neuron.

Sensory neuron

Nerve cell that carries messages from sense receptors toward the central nervous system, also called an afferent neuron.

All-or-none principle

Refers to the fact that the action potential in the axon occurs either full-blown or not at all.

Gene

Segment of a chromosome that encodes the directions for the inherited physical and mental characteristics of an organism. Genes are functional units of a chromosome

Pituitary gland

The "master gland" that produces hormones influencing the secretions of all other endocrine glands, as well as a hormone that influences growth. The pituitary is attached to the brain's hypothalamus, from which it takes its orders

Sex chromosomes

The X and Y chromosomes that determine our physical sex characteristics

Central nervous system

The brain and the spinal chord

Natural selection

The driving force behind evolution, by which the environment "selects" the fittest organisms.

Resting potential

The electrical charge of the axon in its inactive state, when the neuron is ready to "fire"

Nervous system

The entire network of neurons in the body, including the central nervous system, the peripheral nervous system, and their subdivisions.

Endocrine system

The hormone system - the body's chemical messenger system, including the endocrine glands: pituitary, thyroid, parathyroid, adrenals, pancreas, ovaries, and testes.

Synapse

The microscopic gap that serves as a communications link between neurons. Synapse also occur between neurons and the muscles or glands they serve

Action potential

The nerve impulse caused by a change in the electrical charge across the cell membrane of the axon. When the neuron "fires," this charge travels down the axon and causes neurotransmitters to be released by the terminal buttons.

Plasticity

The nervous system's ability to adapt or change as the result of experience. Plasticity may also help the nervous system adapt to physical change

Soma

The part of a cell (such as neuron) containing the nucleus, which includes the chromosomes, also called the cell body.

parasympathetic nervous system

The part of the autonomic nervous system that monitors the routine operations of the internal organs and returns the body to calmer functioning after arousal by the sympathetic division

Sympathetic division

The part of the autonomic nervous system that sends messages to internal organs and glands that help us respond to stressful and emergency situations.

Synaptic transmission

The relaying of information across the synapse by means of chemical neurotransmitters.

Biopsychology

The specialty in psychology that studies the interaction of biology, behavior, and mental processes.

Chromosome

Tightly coiled threadlike structure along which the genes are organized, like beads on a necklace. Chromosomes consist primarily of DNA

Terminal buttons

Tiny bulblike structures at the end of the axon, which contain neurotransmitters that carry the neuron's message into the synapse.

Evolution

the gradual process of biological change that occurs in a species as it adapts to its environment