Flashcards in Exam 2: Nervous System I Deck (35):
1
Central Nervous System
-brain and spinal cord
-control center
-president
2
Peripheral Nervous System (PNS)
-cranial nerves, spinal nerves and ganglia
-ganglion=group of neuron cell bodies located outside CNS
-workers
3
Sensory (afferent) Division
receives information FROM body and transmits it TO CNS for processing
-has both CNS and PNS parts
4
Somatic Sensory
-part of sensory division
-receives sensory information from skin, joints, muscle, special senses (vision, hearing, balance, smell, taste)
5
Visceral Sensory
-part of sensory division
-receives sensory info from blood vessels and viscera
6
Motor Division
transmits info FROM the CNS To muscles and glands
-has both CNS and PNS parts
7
Somatic Motor
-part of motor division
-innervate skeletal muscle
-voluntary
8
Autonomic Motor
-part of motor division
-innervates smooth muscle, cardiac muscle, and glands of viscera (organs)
-involuntary
9
Neurons
-respond to stimuli and conduct nerve impulses
-primarily amitotic
10
Glial Cells
-support and protect neurons
-many more glial cells than neurons
-divide by mitosis
11
Cell Body of Neuron
-function: neuron's control center or head
12
Nucleus
--houses DNA
-contains nucleolus for protein synthesis
13
Chromatophilic substances (Nissl bodies)
-rough ER inside cell body
-function: protein synthesis
-look like darkened clumps within cytoplasm
-no chromatophilic substance in axon hillock
14
Dendrites
-short nerve cell process
-function: receive input (incoming nerve impulses)
-send nerve cells to cell body
-neuron can have 1 or many dendrites
15
Axon
-long nerve cell process
-function: send output (outgoing nerve impulses
-one axon per neuron
16
Axon Hillock
-portion of the cell body from where the axon originates
-no chromatophilic substance here
17
Multipolar Neuron
-one axon and many dendrites
-most common
-ex: motor neurons, interneurons
18
Bipolar Neuron
-two processes: one axon and one dendrite
-limited in location (rare)
-ex: retina of eye, olfactory neurons in nose
19
Unipolar (Pseudounipolar) Neuron
-Single process comes off of the cell body and divides into two branches
-common
-most (not all) sensory neurons
20
Sensory (afferent) Neuron
-brings information TO CNS
-either unipolar or bipolar neurons
21
Motor (efferent) Neuron
-takes information FROM CNS to other parts of the body
-all are multipolar
22
Interneuron
-help coordinate and integrate info between sensory and motor neurons
-located solely in CNS
-"translator/mediator"
-multipolar in form
23
Neuron Classification
-by structure or by function
24
Satellite Cells
-In PNS
-surround neuron cell bodies in spinal ganglia
-protect the cell bodies
-regulate nutrient exchange and waste removal
25
Neurolemmocytes (Schwann Cells)
-myelinate axons in PNS
-myelin is a protective covering around axon that insulates axon and helps produce faster nerve impulses
-can also help regenerate damaged PNS axons
26
Astrocytes
-in CNS
-regulate transfer of materials from blood to the brain, help workings of BBB
-helps make blood vessels less leaky
27
Blood Brain Barrier
-keeps harmful substances away from brain
-selectively permeable
-bust some needed substances can't pass this barrier either like chemotherapy drugs
28
Astrocytes and the BBB (Parkinsons)
-caused by a decrease of a dopamine
-dopamine can't pass the BBB but a related drug, L-dopa, can.
-Cocaine and methamphetamine pass through and damage BBB
29
Oligodendrocytes
-myelinates multipe axons in CNS
-to CNS as neurolemmocytes are to PNS
30
Microglia
-phagocytize damaged neurons in CNS
-replicate when there is CNS damage and need to clean up an area
31
Ependymal Cells
-line central canal and ventricles of CNS
-help circulate CSF
-central canal and ventricles are spaces within the spinal cord and brain respectively
32
Myelination
-process of wrapping an axon with myelin
-myelin insulates axon, produces a faster nerve impulse
-dendrites are not myelinated
33
Myelination Procedure in PNS
-Neurolemmocyte wraps around a 1 mm portion of an axon successively
-Cytoplasm and nucleus of neurolemmocyte gets "squeezed" to the outside
-inner successive layers of cell membrane make up the myelin sheath of neurolemocyte
34
Neurofibril Nodes (Nodes of Ranvier)
-separate neurolemmocytes
-axon unmyelinated here
-nerve impulse is generated at these nodes
35