Neurobiology definitions Flashcards
Afferent neuron
Pathways that carry sensory information from body to central nervous system.
Axon
A typically long extension, or process, of a neuron that carries nerve impulses away from the cell body towards target cells.
Axon (nerve) terminal
Enlarged, club shaped endings of axon by which axons make synaptic contacts with other nerve or effector cells. They also contain neurotransmitters.
Axon hillock
Specialized part of the cell body of a neuron that connects it to the axon.
Cell body
Nucleus - containing central part of the neuron that is the major structural element of grey matter in the brain and spinal cord.
Central canal (spinal canal)
Filled with CSF that runs through spinal cord Connected to ventricular system of brain.
Dendrites
One of usually numerous, short, highly branched extensions of a neuron that receive signals from other neurons.
Dorsal
On or reaching to the upper side or back of an animal, plant, or organ.
Dorsal (posterior) horn
Longitudinal subdivision of grey matter in dorsal part of each lateral half of the spinal cord that receives terminals from fibres of dorsal roots of spinal nerves.
Dorsal fissure
A shallow vertical groove in the closed part of the medulla oblongata, continuous with the posterior median fissure of the spinal cord.
Dorsal root
The one of the two roots of a spinal nerve that passes posteriorly to the spinal cord separating the posterior and lateral funiculi and that consists of sensory fibres.
Effector
An organ or cell that responds to stimulus.
Efferent neuron
Conducting cells that carry information from central nervous system to muscles and organs throughout the body.
Endoneurial sheath (endoneurium)
Protective sheath around each nerve fibre.
Epineurial sheath (epineurium)
Outermost layer of dense irregular connective tissue surrounding a peripheral nerve.
Epithelial cells
Layers of cells that line hollow organs and glands. It is also those cells that make up the outer surface of the body.
Grey matter
Neuronal cell bodies, neuropil (dendrites and unmyelinated axons), glial cells (astroglia and oligodendrocytes), and capillaries.
Interneuron
Transmit signal nerves within the CNS.
Muscle
A band or bundle of fibrous tissue in a human or animal body that can contract, producing movement in or maintaining the position of parts of the body.
Nerve (neuron)
A specialized cell transmitting nerve impulses.
Neurilemmal / Schwann cell
Outermost nucleated cytoplasmic layer of Schwann cells that surround axon of the neuron serving a protective function for peripheral nerve fibres.
Neuroglia / glial cells
Cells of the nervous system that support, regulate, and augment the functions of neurons.
Neuromuscular junction
Neuromuscular junction, also called myoneural junction, site of chemical communication between a nerve fibre and a muscle cell.
Node of Ranvier
Gaps between myelin sheath which contains voltage- gated sodium channels allowing for the action potential to jump from one node to another, increasing speed of transmission of signal.
