Nervous System (General) Flashcards
(113 cards)
What are ganglion?
Clusters of cell bodies in the peripheral nervous system
What is a nucleus?
a cluster of cell bodies in the central nervous system; is post-mitotic, therefore cannot replicate itself; connected to synapses, not cytoplasm
What are nerves?
A collection of neuron axons in the PNS
What are tracts?
Collections of neuron axons in the CNS
How would you describe sensory nerves that are directed towards the brain?
afferent
What would you consider tracts that move away from the brain?
efferent
What is grey matter?
Nervous tissue that has unmyelinated neuronal cell bodies and axons (such as the neocortex)
What is white matter?
Myelinated axons with neuronal tracts
What are layers or nuclei?
well-defined group of neuronal cell bodies (many, vs. nucleus of neuron)
What is the parenchyma?
the tissues/cells associated with brain function e.g. neurons and glia)
What is, and what does a neuron do?
an individual cell that is ‘electrically irritable’ communicating and computing cells of nervous system
What is, and what is the function of glia?
Supporting cells for immune and structural support (prevents infections, etc.) which aid in the transfer of materials from blood to neurons, etc.
What are the 3 main types of functional cells?
Sensory, motor, and interneurons
What are sensory neurons?
Afferent neurons that carry info. from receptors in the PNS to the brain
What are motor neurons?
efferent neurons that carry signals from the brain (CNS) to the muscles
What are interneurons?
Those which are not connected only to other neurons, not muscles or receptors
What is the morphologic diversity of neurons
the shape of neurons, and their arborization
What is described as a highly-arborized neuron?
Those which are densely-branched, and therefore with many dendrites for a multitude of channels, as opposed to highly-specialized neurons in low-arborization
What would you consider s neuron that has two facets?
bipolar neuron
What is an astrocyte?
a star-shaped glia cell which regulates the transmission of electrical impulses within the brain
What are microglia?
Tiny cells in the brain (roughly encompassing 10 - 15% of brain cells) which are macrophages of foreign bodies, acting as a main defense in CNS
What are macrophages?
cells which takeover foreign cells, etc. by ‘eating’ them; usually a process of immunal support
What are ependymal cells?
Cells which line the cerebrospinal fluid-filled ventricles in the brain, and central canal of the spinal cord; nervous tissue cells with ciliated simple columnar form like mucosal or epithelial cells
What are oligodendrocytes?
Cells which wrap around a select few cells, which cannot regenerate if damaged (in the CNS); provide support and insulation to axons in CNS of some vertebrates