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.
Nucleolus
A small dense spherical structure in the nucleus of a cell during interphase.
Nucleus
The central dense organelle in eukaryotic cells that contains genetic material.
Receptor
An organ or cell able to respond to light, heat or other external stimulus and transmit a signal to a sensory nerve.
Sensory neurons
A type of neuron that transmits sensory nerve impulses.
Spinal cord
A column of nerve tissue that runs from the base of the skull down the centre of the back. It is covered by three thin layers of protective tissue called membranes.
Taste bud
Any of the clusters of bulbous nerve endings on the tongue and in the lining of the mouth which provide the sense of taste.
Taste pore
Any of the small openings in the tongue epithelium that allow dissolved food to meet the taste receptors.
Transduction
The action or process of converting something, especially energy or a message into another form.
Ventral
On or relating to the underside of an animal, plant, or organ.
Ventral (anterior) root
One of two roots of a spinal nerve that passes anteriorly from the spinal cord.
Ventral fissure
A groove along the anterior midline of the spinal cord that incompletely divides it into symmetrical halves.
Ventral horn
Front column of grey matter in the spinal cord.
White matter
Myelin sheath becomes myelinated axons.
