BBB

cell body/stoma

The part of a neuron that contains the nucleus; the cell’s life-support center.

dendrites

A neuron’s often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body.

axon

The neuron extension that passes messages through its branches to other neurons or to muscles or glands.

neuron

A nerve cell; the basic building block of the nervous system.

myelin sheath

A fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next.

glial cells (glia)

Cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory.

action potential

rapid change in the voltage across a neuron's membrane that allows neurons to communicate with each other

threshold

The level of stimulation required to trigger a neural impulse.

refractory period

A brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state.

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.

neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons.

reuptake

A neurotransmitter’s reabsorption by the sending neuron.

endorphins

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

agonist

A molecule that increases a neurotransmitter’s action.

antagonist

A molecule that inhibits or blocks a neurotransmitter’s action.

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 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 neurons

Neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord.

motor 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; they communicate internally and process information between the sensory inputs and motor outputs.

somatic nervous system

The division of the peripheral nervous system that controls the body’s skeletal muscles.

autonomic nervous system (ANS)

The part of the peripheral nervous system that controls the glands and the muscles of the internal organs.

sympathetic nervous system

The division of the autonomic nervous system that arouses the body, mobilizing its energy.

parasympathetic nervous system

A division of the autonomic nervous system responsible for rest-and-digest functions, promoting relaxation and energy conservation

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.

adrenal glands

A pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress.

pituitary gland

The endocrine system’s most influential gland; regulates growth and controls other endocrine glands.

lesion

Tissue destruction; a brain lesion is a naturally or experimentally caused destruction of brain tissue.

MRI (magnetic resonance imaging)

A technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue.

fMRI (functional MRI)

A technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans.

brainstem

The oldest part and central core of the brain, responsible for automatic survival functions.

medulla

The base of the brainstem; controls heartbeat and breathing.

thalamus

The brain’s sensory control center, directing messages to the sensory receiving areas.

reticular formation

A nerve network that travels through the brainstem into the thalamus and plays an important role in controlling arousal.

cerebellum

The 'little brain' at the rear of the brainstem; involved in processing sensory input and coordinating movement output.

limbic system

Neural system located below the cerebral hemispheres, associated with emotions and drives.

amygdala

Two lima-bean-sized neural clusters in the limbic system linked to emotion.

hypothalamus

controls various autonomic functions, including temperature regulation, hunger, thirst, and circadian rhythms. It also plays a crucial role in hormone release and the regulation of the pituitary gland.

hippocampus

A neural center located in the limbic system; helps process and store explicit memories.

cerebral cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information-processing center.

frontal lobes

The portion of the cerebral cortex involved in speaking, muscle movements, and making plans and judgments.

parietal lobes

The portion of the cerebral cortex that receives sensory input for touch and body position.

occipital lobes

The portion of the cerebral cortex that includes areas receiving information from the visual fields.

temporal lobes

The portion of the cerebral cortex that includes the auditory areas.

motor cortex

An area at the rear of the frontal lobes that controls voluntary movements.

somatosensory cortex

An area at the front of the parietal lobes that registers and processes body touch and movement sensations.

association areas

Areas of the cerebral cortex involved in higher mental functions such as learning, remembering, thinking, and speaking.

plasticity

The brain’s ability to change, reorganizing after damage or adjusting based on experience.

neurogenesis

The formation of new neurons.

corpus callosum

The large band of neural fibers connecting the two brain hemispheres.

split brain

A condition resulting from surgery that isolates the brain’s two hemispheres.

cognitive neuroscience

The interdisciplinary study of the brain activity linked with cognition.

blindsight

A condition in which a person can respond to a visual stimulus without consciously experiencing it.

behavior genetics

The study of the relative power and limits of genetic and environmental influences on behavior.

heredity

The genetic transfer of characteristics from parents to offspring.

environment

Every nongenetic influence impacting us.

chromosomes

Threadlike structures made of DNA molecules containing genes.

DNA (deoxyribonucleic acid)

A complex molecule containing genetic information.

genes

The biochemical units of heredity that make up chromosomes.

genome

The complete instructions for making an organism, consisting of all genetic material in chromosomes.

identical (monozygotic) twins

Twins that develop from a single fertilized egg that splits in two.

fraternal (dizygotic) twins

Twins that develop from separate fertilized eggs.

interaction

The interplay that occurs when the effect of one factor depends on another factor.

molecular genetics

The subfield studying the molecular structure and function of genes.

molecular behavior genetics

The study of how genes interact with the environment to influence behavior.

epigenetics

The study of environmental influences on gene expression without a DNA change.

evolutionary psychology

The study of the evolution of behavior and the mind.

natural selection

The principle that inherited traits that better enable survival and reproduction are passed on.

mutation

A random error in gene replication that leads to a change.

Broca's area

A region in the frontal lobe of the dominant hemisphere (usually the left) associated with the production of speech; damage to this area can result in difficulties in speech production.

Wernicke's area

A region in the brain's left temporal lobe that is crucial for language comprehension; damage to this area can result in difficulties understanding spoken or written language.

social script

a culturally modeled guide for how to act in various situations.

longitudinal fissure

is the deep groove that separates the two cerebral hemispheres in the brain.

Reflex arc

The simplest neural pathway that mediates reflex actions, consisting of a sensory neuron, an interneuron (in some cases), and a motor neuron.

hindbrain

The back part of the brain, consisting of the cerebellum, pons, and medulla; responsible for regulating important functions such as breathing, heart rate, and motor control.

Forebrain

The forward part of the brain that controls complex behaviors, sensory processing, and emotions, which includes structures such as the thalam

midbrain

The part of the brain located between the hindbrain and forebrain, responsible for functions such as vision, hearing, motor control, sleep and wakefulness, arousal, and temperature regulation.

old reptilian brain

the oldest part of the brain responsible for basic survival functions and instincts

old mammalian brain

the part of the brain that’s responsible for basic emotions, survival instincts, and fundamental behaviors like feeding, mating, and fighting

new mammalian brain

The modern part of the brain responsible for planning, decision making, complex emotions, and self control

dopamine

involved in pleasure and rewards, motor control, motivation, and cognitive functions

serotonin

involved in regulation of mood and sleep patterns, sexual desire, appetite, and happiness

acetylcholine

involved in muscle action, learning, and memory

glutamate

involved in major excitatory neurotransmitters, oversupply can cause migraines and seizures

substance P

pain

GABA

involved in inhibitory, calming effect, undersupply can lead to seizures, migraines, and insomnia

norepinephrine

involved in sleep/wake cycle, fight or flight, and alertness

temporal lobe

parietal lobe

cerebellum

where is the auditory cortex

temporal lobe

where is the somatosensory cortex located

parietal lobe

where is the motor cortex

frontal lobe