Nervous system, neurons and supporting cells Flashcards
What are the two communication and control systems of the body?
the nervous system and the endocrine system
What connects the nervous system and the endocrine system?
hypothalamus
What are the chemical messengers of the nervous system and what are they produced by?
neurotransmitters, neurons
Neurotransmitters travel only very short distances, across spaces between nerve cells called what? And what do these spaces allow?
synapses, the system to react quickly
What are the chemical messengers of the endocrine system and where are they secreted?
hormones, directly into the bloodstream
What are the two divisions of the nervous system and what are they composed of?
central nervous system - brain and spinal cord
peripheral nervous system - cordlike nerves that link the central nervous system with the rest of the body
What are the three functions of the nervous system and how do they work?
sensory - senses changes from within the body or from outside the body and conveys this info to the spinal cord and brain
integrating - sensory info is received, analyzed, stored and INTEGRATED to produce a response
motor - instructs the body to do something, such as contract a muscle or cause a gland to secrete product(s)
What are nerve cells called?
neurons
What do neurons require and can only live minutes without it?
oxygen
Shortly after birth, neurons lose their ability to what?
reproduce
Neurons can regenerate cell processes if what remains in tact?
the cell body
What structurally and functionally supports and protects neurons?
neuroglia
How are the structures of the neuron divided?
central cell body and two different types of processes
What is the central cell body of a neuron called?
soma
What are the two different processes of a neuron?
dendrites and axons
Which neuron cell process receives stimuli or impulses from other neurons and conducts this stimulation to the cell body?
dendrite
Means to conduct impulses toward the cell body
afferent
Dendrites can be modified into _____, that receive, or sense stimuli from inside or outside of the body?
sensory receptors
Which neuron process is short, numerous and have many branches?
dendrites
Which neuron process conducts nerve impulses away from the cell body, toward another neuron?
axon
What is another term for axon?
effector cell
Means to conduct impulses away from the cell body
efferent
Which neuron process is singular and may be very long
axon
Bundles of axons that make up cord like nerves
nerve fibers
Protective fatty substance that covers axons
myelin
nervous tissue containing many myelinated axons is called what (because of the color of myelin grossly)
white matter
nervous tissue that is made up largely of neuron cell bodies is called what
gray matter
Where are oligodendrocytes found
myeline sheath of the brain and spinal cord (CNS)
Where are Schwann cells found
myeline sheath of the nerves outside of the brain and spinal cord (PNS)
what is the myelin sheath made up of
cell membranes of specialized glial cells
small gaps in the the myelin sheath of adjacent glial cells
nodes of Ranvier
What kind of axons conduct nerve impulses faster
myelinated axons
