Card Set Information
Cells of the nervous system
Which system is referred to as the communicating system of the body?
What type of information is sensory input?
what type of information is motor output?
what 2 structures make up the central enrvous system?
What is the peripheral nervous system?
-cranial and spinal nerves
what are 2 subdivisions of motor division (efferent)?
-autonomic nervous system
-somatic nervous system
What arethe 2 subdivisions of autonomic nervous system?
description of autonomic nervous system (2)
-conducts impulses from CNS to cardiac muscles,smooth, and glands
description of somatic nervous system (2)
-conducts impulses from the CNS to skeletal muscles
description of sympathetic division
-mobilizes body systems during emergency situations
description of parasympathetic division (2)
-promotes nonemergency functions
what are neurons?
excitable cells that transmit an electrical signal or action potential
What are the supporting cells in the CNS called?
what are the supporting cells in the PNS called? (2)
schwann cells and satalite cells
do neurons replicate?
Are neurons highly metabolic or not?
yes, require abundant supply of oxygen and glucose
What does myelin sheeth do?
insulates the axon to speed up transmission
What are the spaces between schwann cells called?
nodes of ranvier
where does the axon arise from?
Do neurons contain mitotic spindles?
no, bc they do not replicate
Which type of structural neuron is the most common?
Where are unipolars located?
where are mulitpolar ususally lcoated?
Do supporting cells conduct an AP?
Neurons and SUpporting cells: which is there more?
(neuroglia in CNS) fucntions of Astrocyte (3)
-exchange between capillaries and neurons
-control chemical environment
*maintain ion concentration
-take up NTs
(neuroglia in CNS) fucntions of Microglial cell (2)
-monitor health of neurons
(neuroglia in CNS) functions of ependymal cells (2)
-help form cerebrospinal fluid
-help circulate cerebrospinal fluid
(neuroglia in CNS) function of Oligodendrocyte
form myelin sheath in the CNS
Supporting cells in PNS) function of satellite cells (2)
-surround the cell bodies of neurons in ganglia
-supportive to neurons
*take care of neurons health and environment
Supporting cells in PNS) fucntion of schwann cells?
form the myelin sheath in the PNS
factors affecting conduction velocity) axon diameter
-the larger the diameter of the axon the faster it will conduct a current
factors affecting conduction velocity) myelin sheath
-myelinated axons conduct impulses faster than unmyelinated axons
What is continuous conduction? (2)
-AP are generated at sites immediately adjacent to each other
-conduction is relatively slow
what is saltatory conduction? (2)
-prescence of myelin sheath allows AP to be generated only nodes of ranvier
-speeds up conduction
What are nodes of ranvier?
spaces between adjacent schwann cells
What does the myelin sheath wrap around?
classification of nerve fibers) description of group A (4)
-somatic sensory and motor fibers
-largest degree of myelination
classification of nerve fibers) description group B (2)
-innervate the viscera and pain fibers from the skin
classification of nerve fibers) group C (4)
-visceral and some pain and touch
-slowest conducting from the other 3
layers of connective tissue which cover nerve processes) description of epineurium? (2)
-covers the entire nerve
layers of connective tissue which cover nerve processes) description of perineurium (2)
- covers fasiscles
*covers a bundle of nerve processes
layers of connective tissue which cover nerve processes) description of endoneurium (2)
-covers individual processes of a neuron
*within each endoneurium there is a myelin sheath and axon