Appendix Flashcards
cell
basic biological unit of life, defined by a membrane or wall that encloses cytoplasm and, in eukaryote organisms (including all plants and animals), a nucleus
neuroglial cells
several types of non-neural cells found in the peripheral and central nervous systems that carry out a variety of functions that do not directly entail signalling
cell body/soma
portion of a neuron that houses the cell’s nucleus; axons and dendrites typically extend from the neuronal cell body
organelle
subcellular component visible in a light or electron microscope (e.g., nucleus, ribosome, endoplasmic reticulum)
axon
extension of a neuron that carries the action potential from the nerve cell body to a target
dendrite
extension of a neuron that receives synaptic input; usually branches near the cell body
neural circuit
collection of interconnected neurons mediating a specific function
axon hillock
initial portion of an axon, closest to the cell body; the point where action potentials are typically initiated
ion channels
membrane protein that uses the passive energy of concentration gradients (created by ion pumps) to allow the passage of ions across the cell membrane
ion pump
membrane protein that uses metabolic energy to create ion concentration gradients across neuronal membranes
chemical synapse
synapse that uses a chemical transmitter agent; the most common type of synapse in the mammalian brain
synaptic cleft
small space between a presynaptic and postsynaptic element across which neurotransmitters must diffuse when released
neurotransmitter receptor
molecule embedded in the membrane of a postsynaptic cell that binds a neurotransmitter
synaptic vesicle
organelle at a synaptic ending that contains neurotransmitter agents
afferent neuron
axon that conducts action potentials from the periphery to more central parts of the nervous system
efferent neuron
axon that conducts information away from the central nervous system
interneuron
neuron in a circuit that lies between primary sensory and primary effector neurons;
neuron that branches locally to innervate other neurons
spinal reflex arc
circuit that includes the afferent to efferent components of a response at the level of the spinal cord
sensory neuron
nerve cell that is involved in sensory processing
motor neuron
nerve cell that innervates skeletal or smooth muscle
excitatory
pertaining to a synaptic effect that brings the membrane of the postsynaptic cell closer to threshold, thereby making firing of the postsynaptic cell more likely
inhibitory
pertaining to a synaptic effect that makes the firing of the postsynaptic cell less likely
electrophysiological recording
various methods of recording electrical activity in the nervous system
synaptic potential
membrane potential change (or a conductance change) generated by the action of a chemical transmitter agent. Synaptic potentials allow the transmission of information from one neuron to another