AP Psych - Chapter 3: Biopsychology and the Foundations of Neuroscience

Biopsychology

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

Neuroscience

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

Evolution

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

Natural selection

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

Genotype

An organism's genetic makeup (the "blueprint").

Phenotype

An organism's observable physical characteristics.

Deoxyribonucleic acid (DNA)

A long, complex molecule that encodes genetic characteristic.

Gene

Segment of a chromosome that encodes the directions for the inherited physical and mental characteristics of an organism; the functional units of a chromosome (the "words").

Chromosomes

Tightly coiled threadlike structure along which the genes are organized (the "paragraphs"); consists primarily of DNA.

Sex chromosomes

The X and Y chromosomes that determine our physical sex characteristics.

Neuron

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

Sensory/afferent neuron

Nerve cell that carries messages from sense receptors toward the central nervous system.

Motor/efferent neuron

Nerve cells that carries messages away from the central nervous system toward the muscles and glands.

Interneuron

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

Dendrite

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

Soma/cell body

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

Axon

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

Resting potential

The electrical charge of the axon in its inactive state, when the neuron is ready to "fire;" has a small negative charge.

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.

All-or-none principle

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

Synapse

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

Terminal buttons

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

Synaptic transmission

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

Synaptic vesicle

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

Neurotransmitters

Chemical messengers that relay neural messages across the synapse; many are also hormones.

Plasticity

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

Glial cells

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

Nervous system

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

Central nervous system

The brain and spinal cord; serves as the body's "command center.

Reflex

A simple, unlearned response triggered by stimuli; does not require brain power.

Peripheral nervous system

All parts of the nervous system lying outside the central nervous system; connects the CNS with the rest of the body ("pick-up-and delivery system"); includes the autonomic and somatic nervous systems.

Somatic nervous system

A division of the peripheral nervous system that carries sensory information to the central nervous system and also sends voluntary messages to the body's skeletal muscles.

Autonomic nervous system

The portion of the peripheral nervous system that sends communications between the central nervous system and the internal organs and glands.

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.

Parasympathetic division

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.

Endocrine system

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

Hormone

A chemical messenger used by the endocrine system; many also serve as neurotransmitters.

Pituitary gland

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

Agonist

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

Antagonist

Drug or other chemical that inhibits the effects of neurotransmitters.

Neural pathway

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

Electroencephalograph (EEG)

A device for recording brain waves, typically by electrodes placed on the scalp.

Computerized tomography (CT scanning)

A computerized imaging technique that uses X-rays passed through the brain at various angles and then combined into an image.

Positron emission tomography (PET scanning)

An imaging technique that relies on the detection of radioactive sugar consumed by active brain cells.

Magnetic resonance imaging (MRI)

An imaging technique that relies on cells' responses in a high-intensity magnetic field.

Functional magnetic resonance imaging (fMRI)

A type of MRI that reveals which parts of the brain are most active during various mental activities.

Brain stem

The most primitive of the brain's three major layers; includes the medulla, pons, and reticular formation.

Medulla

A brain-stem structure that controls breathing and heart rate. The sensory and motor pathways connecting the brain to the body cross here.

Pons

A brain-stem structure that regulates brain activity during sleep and dreaming.

Reticular formation

A pencil-shaped structure forming the core of the brian stem; arouses the cortex to keep the brain alert and attentive to new stimulation.

Thalamus

The brain's central "relay station," situated just atop the brain stem; nearly all messages going into or out of the brain go through the thalamus.

Cerebellum

The "little brain" attached to the brain stem; responsible for coordinated movements.

Limbic system

The middle layer of the brain, involved in emotion and memory; includes the hippocampus, amygdala, hypothalamus, and other structures.

Hippocampus

A component of the limbic system, involved in establishing long-term memories.

Amygdala

A limbic system structure involved in memory and emotion, particularly fear and aggression.

Hypothalamus

A limbic structure that serves as the brain's blood-testing laboratory, constantly monitoring the blood to determine the condition of the body.

Cerebral cortex

The thin gray-matter covering of the cerebral hemispheres, consisting of a 1/4 inch layer dense with cell bodies of neurons; carries on the major portion of our "higher" mental processing, including thinking and perceiving.

Frontal lobes

Cortical regions at the front of the brain that are especially involved in movement and in thinking.

Motor cortex

A narrow vertical strip of cortex in the frontal lobes, lying just in front of the central fissure; controls voluntary movement.

Parietal lobes

Cortical areas lying toward the back and top of the brain; involved in touch sensation and in perceiving spatial relationships (the relationships of objects in space).

Somatosensory cortex

A strip of the parietal lobe lying just behind the central fissure; involved with sensations of touch.

Occipital lobes

The cortical regions at the back of the brain, housing the visual cortex.

Visual cortex

The visual processing areas of cortex in the occipital and temporal lobes.

Temporal lobes

Cortical lobes that process sounds, including speech; probably involved in storing long-term memories.

Association cortex

Cortical regions throughout the brain that combine information from various other parts of the brain.

Cerebral dominance

The tendency of each brain hemisphere to exert control over different functions, such as language (left hemisphere) or perception of spatial relationships (right hemisphere).

Corpus collosum

The band of nerves that connects the two cerebral hemispheres.