acetylcholine
neurotransmitter released by neurons in the central nervous system and peripheral nervous system
action potential
self-propagating momentary change in the electrical potential of a neuron (or muscle) membrane
Alzheimer’s disease
neurodegenerative disorder characterized by problems with memory and thinking
amygdala
structure within the limbic system that processes fear
arachnoid mater
spiderweb-like middle layer of the meninges that cover the central nervous system
astrocyte
glial cell in the central nervous system that provide nutrients, extracellular buffering, and structural support for neurons; also makes up the blood-brain barrier
attention deficit hyperactivity disorder (ADHD)
neurodevelopmental disorder characterized by difficulty maintaining attention and controlling impulses
autism spectrum disorder (ASD)
neurodevelopmental disorder characterized by impaired social interaction and communication abilities
autonomic nervous system
part of the peripheral nervous system that controls bodily functions
axon
tube-like structure that propagates a signal from a neuron’s cell body to axon terminals
axon hillock
electrically sensitive structure on the cell body of a neuron that integrates signals from multiple neuronal connections
axon terminal
structure on the end of an axon that can form a synapse with another neuron
basal ganglia
interconnected collections of cells in the brain that are involved in movement and motivation; also known as basal nuclei
basal nuclei
see basal ganglia
brainstem
portion of the brain that connects with the spinal cord; controls basic nervous system functions like breathing, heart rate, and swallowing
cerebellum
brain structure involved in posture, motor coordination, and learning new motor actions
cerebral cortex
outermost sheet of brain tissue; involved in many higher-order functions
cerebrospinal fluid (CSF)
clear liquid that surrounds the brain and spinal cord and fills the ventricles and central canal; acts as a shock absorber and circulates material throughout the brain and spinal cord.
choroid plexus
spongy tissue within ventricles that produces cerebrospinal fluid
cingulate gyrus
helps regulate emotions and pain; thought to directly drive the body’s conscious response to unpleasant experiences
corpus callosum
thick fiber bundle that connects the cerebral hemispheres
cranial nerve
sensory and/or motor nerve that emanates from the brain
dendrite
structure that extends away from the cell body to receive messages from other neurons
depolarization
change in the membrane potential to a less negative value
dura mater
tough outermost layer that covers the central nervous system
ependymal
cell that lines fluid-filled ventricles of the brain and the central canal of the spinal cord; involved in production of cerebrospinal fluid
epilepsy
neurological disorder characterized by recurrent seizures
excitatory postsynaptic potential (EPSP)
depolarization of a postsynaptic membrane caused by neurotransmitter molecules released from a presynaptic cell
frontal lobe
part of the cerebral cortex that contains the motor cortex and areas involved in planning, attention, and language
glia
(also, glial cells) cells that provide support functions for neurons
gyrus
(plural: gyri) ridged protrusions in the cortex
hippocampus
brain structure in the temporal lobe involved in processing memories
hyperpolarization
change in the membrane potential to a more negative value
hypothalamus
brain structure that controls hormone release and body homeostasis
inhibitory postsynaptic potential (IPSP)
hyperpolarization of a postsynaptic membrane caused by neurotransmitter molecules released from a presynaptic cell
limbic system
connected brain areas that process emotion and motivation
long-term depression (LTD)
prolonged decrease in synaptic coupling between a pre- and postsynaptic cell
long-term potentiation (LTP)
prolonged increase in synaptic coupling between a pre-and postsynaptic cell
major depression
mental illness characterized by prolonged periods of sadness
membrane potential
difference in electrical potential between the inside and outside of a cell
meninge
membrane that covers and protects the central nervous system
microglia
glia that scavenge and degrade dead cells and protect the brain from invading microorganisms
myelin
fatty substance produced by glia that insulates axons
neurodegenerative disorder
nervous system disorder characterized by the progressive loss of neurological functioning, usually caused by neuron death
neuron
specialized cell that can receive and transmit electrical and chemical signals
nodes of Ranvier
gaps in the myelin sheath where the signal is recharged
norepinephrine
neurotransmitter and hormone released by activation of the sympathetic nervous system
occipital lobe
part of the cerebral cortex that contains visual cortex and processes visual stimuli
oligodendrocyte
glial cell that myelinates central nervous system neuron axons
parasympathetic nervous system
division of autonomic nervous system that regulates visceral functions during rest and digestion
parietal lobe
part of the cerebral cortex involved in processing touch and the sense of the body in space
Parkinson’s disease
neurodegenerative disorder that affects the control of movement
pia mater
thin membrane layer directly covering the brain and spinal cord
proprioception
sense about how parts of the body are oriented in space
radial glia
glia that serve as scaffolds for developing neurons as they migrate to their final destinations
refractory period
period after an action potential when it is more difficult or impossible for an action potential to be fired; caused by inactivation of sodium channels and activation of additional potassium channels of the membrane
saltatory conduction
“jumping” of an action potential along an axon from one node of Ranvier to the next
satellite glia
glial cell that provides nutrients and structural support for neurons in the peripheral nervous system
schizophrenia
mental disorder characterized by the inability to accurately perceive reality; patients often have difficulty thinking clearly and can suffer from delusions
Schwann cell
glial cell that creates myelin sheath around a peripheral nervous system neuron axon
sensory-somatic nervous system
system of sensory and motor nerves
somatosensation
sense of touch
spinal cord
thick fiber bundle that connects the brain with peripheral nerves; transmits sensory and motor information; contains neurons that control motor reflexes
spinal nerve
nerve projecting between skin or muscle and spinal cord
sulcus
(plural: sulci) indents or “valleys” in the cortex
summation
process of multiple presynaptic inputs creating EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential
sympathetic nervous system
division of autonomic nervous system activated during stressful “fight or flight” situations
synapse
junction between two neurons where neuronal signals are communicated
synaptic cleft
space between the presynaptic and postsynaptic membranes
synaptic vesicle
spherical structure that contains a neurotransmitter
temporal lobe
part of the cerebral cortex that processes auditory input; parts of the temporal lobe are involved in speech, memory, and emotion processing
thalamus
brain area that relays sensory information to the cortex
threshold of excitation
level of depolarization needed for an action potential to fire
ventricle
cavity within brain that contains cerebrospinal fluid