Ch.13- The Peripheral Nervous System Flashcards
What is the nervous system?
a message system which controls and regulates the body
maintains equilibrium within an organism = homeostasis
maintains equilibrium by negative feedback
 what are the two types of nervous system?
Central nervous system and the peripheral nervous system! Central is for the brain and spinal cord and peripheral is for autonomic nerves and somatic nerves.
What is the peripheral nervous system?
There’s two parts of the peripheral nervous system and that is somatic nervous system and autonomic nervous system.
What is the somatic nervous system?
-Somatic Nervous System***
voluntary control of muscles
ex) writing your biology notes, weightlifting (contract biceps)
What are neurons? 
-special cells with excitable membranes that produce an electrical impulse
1. dendrite
2.cell body
very Complicated can’t grow new one
3. axon
- glial cells - provide support and protection for neurons
Schwann cells - type of glial cell - form sheaths around the axons
neurons communicate with other neurons or with other cells by passing a chemical message across a gap
called a synapse
How is a message/impulse transmitted?
Through dendrites, cell body, Axon, nodes of Ranvier and neurilemma
What is a Autonomic nervous system?
-Autonomic Nervous System***
autonomic = involuntary
controlled by the y hypothalamus, medulla, and spinal cord
two branches
What is the difference between stamatic and Parasympathetic?
- sympathetic =”speed up”
- stimulates the body by releasing nor/epinephrine - parasympathetic
- inhibits the body by returning it back to normal (resting)
What are dendrites?
-receive incoming signals (stimulus)
-deliver signal to cell body
-one neuron can have many dendrites
What is the function of a cell body?
-incoming impulses from dendrites meet at cell body (impulse sent down the axon from the cell body
-cell body makes energy for the neuron
What is axon?
-long arm that conducts nerve impulses away from cell body
-usually polarized with Na* and K* channels and protein pumps along the membrane
-axons of neurons can be coated with a fatty protein called myelin
*acts as an insulator
*wraps around axon
*made by Schwann cells
*by wrapping the axon, it allows the nerve impulse to pass over the wrapped parts faster
*myelinated axons - messages travel 50x faster then no myelin
-grey matter - unmyelinated neurons
found on the inner spinal cord and the outside of the brain
-white matter - myelinated neurons
found on the inside of the brain and the outside of the spinal cord
What is the Nodes of Ranvier?
-gaps between myelin wrapping
-impulse “jumps” from gap to gap and passes over the myelinated areas
What is Neurilemma?
-delicate membrane
-found only on neurons in the peripheral nervous system (not in CNS)
-works to regenerate (heal) a damaged neuron
Be able to draw and label a neuron!!!!
Nucleus, cell body, Swan cell, myelin shaft, actin, dendrites, terminal branches, and plates, and node of Ranvier
What are the different types of neurons?
Sensory neurons, inner neurons, and motor neurons
