Chapter 12 – Introduction to the Nervous System. Organization Cell Types. Review. What 3 parts make up the nervous system? Brain Spinal cord Nerves. http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/19588.jpg. Functions of the Nervous System.
What 3 parts make up the nervous system?
Goal – maintain homeostasis
What does this remind you of??
Nervous pathways are organized into division based on the direction they carry information
(Efferent = Exit)
Nervous pathways are also organized according to the type of effectors (organs) they regulate
What are the two main cell types in the nervous system?
(Hint: we talked about this when we covered tissue types)
Answer: neurons and glia
Neurons: excitable cells that conduct information
Glia (also neuroglia or glial cells): support cells, do not conduct information
Five major types:
All neurons have 3 parts:
How does myelin sheaths affect the speed of an action potential?
Electrical synapses: two cells joined end to end by gap junctions
Ex: btwn cardiac muscle cells, smooth muscles cells
Chemical synapses: use neurotransmitter to send a signal from a presynaptic cell to postsynaptic cell