Nervous System Unit Lesson 1: Nervous Tissue Flashcards
what is the nervous system responsible for
your sight, hearing, smell, touch and taste (the 5 senses). it is also responsible for regulating and performing many bodily functions
what is the nervous system composed of
specialized tissues/cells that perform many functions
how can the specialized cells be grouped
to neurons and neuroglia
what are neurons
cells that transmit nerve impulses
what are neuroglia
cells that support and nourish neurons
how can neurons be further separated
it can be separated based on their function and position relative to the central nervous system(CNS) and the peripheral nervous system(PNS). it can be separated into sensory neurons, interneurons, and motorneurons
what are sensory neurons and what is their function
sensory neurons are neurons that take messages from the peripheral nervous system to the central nervous system. it often uses specialized structures that detect changes in the environment(pressure, light, heat, vibrations, etc.)
what are interneurons, where are they located, and what is their function
these are neurons within the central nervous system that transport messages to other neurons in the central nervous system
what are motor neurons and what is their function
motor neurons are neurons that take messages from the central nervous system to an effector(a portion of the body that performs a function such as a muscle, a gland, an organ, etc.)
describe the basic structure of a neuron
it has a cell body, a dendrite, and an axon
what is the cell body
a portion of the neuron containing the nucleus and organelles
what is the dendrite
tree-like extensions that lead toward the cell body
what is the axon
long, singular extensions that lead away from the cell body
what is the function of the dendrite
they receive stimuli and send signals toward the cell body
what is the function of the axon
they send signals away from the cell body towards other neurons or effectors
what is myelin sheath and what is it used for
it is a lipid-heavy substance that encircles portions of the axon. it is used to accelerate signal transmission
in the peripheral nervous system, what produces myelin sheath
it is produced by neuroglia called Schwann cells
in the central nervous system, what produces myelin sheath
it is produced by neuroglia called oligodendrocytes
go into detail about how myelin sheath works
it insulates portions of the axon so that signal transmission can “jump” along the axon instead of having to run along its entire length
what types of nervous TISSUE is the central nervous system composed of
grey matter and white matter
describe grey matter
tissue containing neurons with short axons that lack myelin.
describe white matter
tissue containing neurons with longer myelinated axons that run in bundles called tracts
describe the white and grey matter in the brain
grey matter exists in the surface layers and white matter is held deeper within the brain
describe white and grey matter in the spinal cord
grey matter exists deep within and white matter makes out the outer layer
