Biological Perspective in Psychology — Neuroscience Key Terms

Neuron

The specialized cell in the nervous system that receives and sends messages within that system.

Nervous system

A network of cells that carries information to and from all parts of the body.

Neuroscience

The branch of life sciences dealing with the structure and functioning of the brain, neurons, nerves, and nervous tissue.

Glial cells

Cells that hold neurons in place, provide nutrients, clean up dead neurons, and provide insulation.

Myelin

A layer of fatty substance generated by glial cells that speeds neural transmission.

Oligodendrocytes

Glial cells that generate myelin in the central nervous system.

Schwann cells

Glial cells that generate myelin in the peripheral nervous system.

Multiple Sclerosis (MS)

A disease in which the myelin sheath is destroyed, impairing neural functioning.

Dendrites

Tree-like parts of a neuron that receive messages from other cells.

Soma

The cell body containing the nucleus that keeps the neuron alive and functioning.

Axon

The fiber extending from the soma that carries messages out to other cells.

Axon terminals (presynaptic terminals, terminal buttons, synaptic knobs)

End branches of the axon that communicate with other neurons at synapses.

Synapse

The fluid-filled gap between presynaptic and postsynaptic neurons across which neurotransmitters travel.

Synaptic vesicles

Presynaptic sacs that store neurotransmitters ready for release.

Vesicle (Latin: ‘little blister’)**

A small fluid-filled sac; the term reflects the vesicles that carry neurotransmitters.

Neurotransmitters

Chemicals suspended in fluid that act as messengers to transmit signals across synapses.

Receptor sites

Proteins on the postsynaptic membrane that fit specific neurotransmitters like a key fits a keyhole.

Diffusion

Movement of ions from areas of high concentration to low concentration.

Electrostatic pressure

Electrical charges influencing ion movement, driving ions toward or away from each other.

Resting potential

The state of a neuron when it is not firing; negatively charged inside, positively charged outside.

Action potential

A rapid rise and fall in membrane potential that propagates along the axon.

Excitatory neurotransmitters

Neurotransmitters that increase the likelihood that the postsynaptic neuron will fire.

Inhibitory neurotransmitters

Neurotransmitters that decrease the likelihood that the postsynaptic neuron will fire.

Excitatory synapses

Synapses with receptor sites that promote postsynaptic activation.

Inhibitory synapses

Synapses with receptor sites that suppress postsynaptic activation.

Acetylcholine (ACh)

A neurotransmitter involved in motor control and arousal.

Dopamine (DA)

A neurotransmitter involved in movement and feelings of pleasure.

GABA (gamma-aminobutyric acid)

The major inhibitory neurotransmitter, involved in sleep and movement inhibition.

Glutamate

The major excitatory neurotransmitter, involved in learning and memory formation.

Endorphins

Inhibitory regulators involved in pain relief.

Norepinephrine (NE)

A neurotransmitter involved in alertness, mood, sleep, anxiety, and appetite.

Serotonin (5-HT)

A neurotransmitter involved in sleep, mood, appetite, and other functions.

Nervous system divisions

Central nervous system (brain and spinal cord) and Peripheral nervous system (transmits to/from CNS).

Central nervous system (CNS)

Brain and spinal cord.

Peripheral nervous system (PNS)

Transmits information to and from the CNS.

Autonomic nervous system

Regulates glands, internal organs, and involuntary functions.

Somatic nervous system

Carries sensory information and controls voluntary movement of skeletal muscles.

Parasympathetic division

Maintains body functions under ordinary conditions; conserves energy.

Sympathetic division

Prepares the body to react and expend energy in times of stress.

Sensory system (afferent)

Carries messages from senses to the CNS.

Motor system (efferent)

Carries messages from the CNS to muscles and glands.

Endocrine glands

Glands that secrete hormones directly into the bloodstream.

Pineal gland

Gland that secretes melatonin and helps track day length.

Pituitary gland

The master gland that regulates other endocrine glands.

Pancreas

An organ that secretes insulin and glucagon to regulate blood sugar.

Thyroid gland

Gland that secretes thyroxin and regulates metabolism.

Adrenal glands

Glands that secrete cortisol, a hormone involved in stress responses.

Gonads (Ovaries and Testes)

Sex glands regulating sexual behavior and reproduction.

Melatonin

Hormone produced by the pineal gland that helps track day length.

Cortisol

Hormone released during stress (physical or psychological).

Thyroxin

Hormone from the thyroid that regulates metabolism.

Cerebral cortex

Outer rind of the brain involved in higher mental functions and processing.

Corpus callosum

Band of nerve fibers connecting the left and right hemispheres.

Thalamus

Relays information from sensory organs to the cerebral cortex.

Hypothalamus

Regulates fear, thirst, sexual drive, and aggression.

Hippocampus

Involved in learning, memory, and comparing sensory information to expectations.

Amygdala

Influences motivation, emotional control, fear responses, and interpretation of emotions.

Medulla

Hindbrain structure that controls heartbeat and breathing.

Cerebellum

Hindbrain structure that controls balance and coordination.

Pons

Relays messages between the cerebellum and the cortex.

Reticular formation

System of nerves controlling arousal and attention from hindbrain through midbrain to cortex.

Occipital lobe

Brain region at the back that processes visual information.

Parietal lobe

Lobe involved in processing touch, temperature, and body position.

Temporal lobe

Lobe involved in hearing and language processing.

Frontal l