Refractory period
The minimum length of time after an action potential during which another action potential cannot begin.
Action potential
A brief change in a neuron's electrical charge.
Adoption studies
Research studies that assess hereditary influence by examining the resemblance between adopted children and both their biological and their adoptive parents
Afferent nerve fibers
Axons that carry sensory information inward to the central nervous system from the periphery of the body.
Agonist
A chemical that mimics the action of a neurotransmitter.
Antagonist
A chemical that opposes the action of a neurotransmitter.
Autonomic nervous system (ANS)
The system of nerves that connect to the heart, blood vessels, smooth muscles, and glands.
Axon
A long, thin fiber that transmits signals away from the neuron cell body to other neurons, or to muscles or glands.
Central nervous system (CNS)
The brain and the spinal cord.
Cerebral cortex
The outer layer of the cerebrum - humans have largest
Chromosomes
Threadlike strands of DNA (deoxyribonucleic acid) molecules that carry genetic information.
Corpus callosum
The structure that connects the two cerebral hemispheres.
Dendrites
Branchlike parts of a neuron that are specialized to receive information.
Efferent nerve fibers
Axons that carry information outward from the central nervous system to the periphery of the body.
Electroencephalograph (EEG)
A device that monitors the electrical activity of the brain over time by means of recording electrodes attached to the surface of the scalp.
Endocrine system
A group of glands that secrete chemicals into the bloodstream that help control bodily functioning.
Fraternal twins
Twins that result when two eggs are fertilized simultaneously by different sperm cells, forming two separate zygotes. Also called dizygotic twins.
Glia
Cells found throughout the nervous system that provide various types of support for neurons.
Hypothalamus
A structure found near the base of the forebrain that is involved in the regulation of basic biological needs.
Identical twins
Twins that emerge from one zygote that splits for unknown reasons. Also called monozygotic twins.
Lesioning
Destroying a piece of the brain.
Mirror neurons
Neurons that are activated by performing an action or by seeing another monkey or person perform the same action. Frontal lobe
Neurotransmitters
Chemicals that transmit information from one neuron to another.
Parasympathetic NS
The branch of the autonomic nervous system that generally conserves bodily resources - calm
Peripheral nervous system
All those nerves that lie outside the brain and spinal cord.
Phenotype
The ways in which a person's genotype is manifested in observable characteristics (hair color, eye color, height, etc)
Pituitary gland
The master gland of the endocrine system; it releases a great variety of hormones that fan out through the body, stimulating actions in the other endocrine glands.
Resting potential
The stable, negative charge of a neuron when it is inactive.
Reuptake
A process in which neurotransmitters are sponged up from the synaptic cleft by the presynaptic membrane.
Soma
The cell body of a neuron; it contains the nucleus and much of the chemical machinery common to most cells.
Somatic NS
The system of nerves that connect to voluntary skeletal muscles and to sensory receptors.
Split-brain surgery
A procedure in which the bundle of fibers that connects the cerebral hemispheres (the corpus callosum) is cut to reduce the severity of epileptic seizures.
Sympathetic NS
The branch of the autonomic nervous system that mobilizes the body's resources for emergencies.
Synapse
A junction where information is transmitted from one neuron to the next.
Terminal buttons
Small knobs at the end of axons that secrete chemicals called neurotransmitters.
Transcranial magnetic stimulation (TMS)
A technique that permits scientists to temporarily enhance or depress activity in a specific area of the brain.
Twin studies
A research design in which hereditary influence is assessed by comparing the resemblance of identical twins and fraternal twins with respect to a trait.
Dopamine
Excitatory - responsible for pleasure, movement, learning, attention - low levels, Parkinson's
Serotonin
Inhibitory - Mood, hunger, sleep, arousal - low levels, depression and anxiety
GABA
Balances excitatory messages - Contributes to regulation of anxiety
Glutamate
Excitatory - Thinking, memory, learning - strengthening neural connections, high levels - agitation and memory loss
Norepinephrine
Excitatory - Alertness & arousal Increasing heartbeat, arousal, memory, learning, and eating
Acetylcholine
Excitatory - Muscle action/contractions; learning/memory - Messenger at every junction between motor neuron & skeletal muscle - low levels, paralysis, Alzheimers
Endorphins
Inhibitory - "morphine within" - natural opiates, pain control and pleasure
Frontal Lobe
planning, judgment, memory, reasoning, abstract thinking, movement (motor cortex) *mirror neurons
Parietal Lobe
Important area governing spatial awareness and navigation - information about touch (sensory cortex), Left hemisphere involved in mathematics, reading, writing and understanding symbols.
Temporal Lobe
hearing (auditory cortex), Wernicke's for language
Occipital Lobe
visual information (visual cortex)
Broca's Aphasia
Damage that makes speech very slow, slurred and labored, no comprehension problems
Wernicke's Aphasia
Damage where speech is incomprehensible - patients have great difficulty understanding - Speech is NOT slurred
Lateralization/contralateral control
hemispheres control the opposite sides of the body
hippocampus
creates, integrates, consolidates memories
Amygdala
Damage to this region leads to decrease in fear, aggression, and sexual desire
hypothalamus
Helps to govern endocrine system and controls maintenance functions - eating and drinking
Cerebellum
enables nonverbal learning, coordinates voluntary movements
Pons
Helps control/regulate sleep, respiration, swallowing
Reticular formation
regulates sleep, wakefulness, and levels of arousal - damage would lead to coma
Medulla
Controls heartbeat and breathing
CT Scan
Provides structural imaging using Xrays
fMRI
Provides functional imaging of active brain areas using magnetic fields
PET Scan
Functional imaging - injected with radioactive substance and detects movement of blood
Plasticity
the ability of the brain to form and reorganize synaptic connections, compensate for damage
General Adaptation Syndrome
Physiological adaptation - alarm, resistance, exhaustion
Prolonged Stress
Can reduce immune functioning and lead to heart disease
Problem focused coping
attempting to directly change the stressor or change the way we interact with it