Ch 12: Nervous System Overview Flashcards
Nervous system
Control hub
CNS
Brain and spinal cord
PNS
Nerves and ganglia outside brain and spinal column
PNS sensory division
Afferent division; Carries signals from dif receptors to CNS
Sensory division of PNS is divided into:
Visceral sensory division and
Somatic sensory division
Viscera
Body organs
Somatic
Skin, skeletal muscles, joints
PNS Motor division is divided into
Visceral motor division or autonomic nervous system which divides into sympathetic division and parasympathetic division
Somatic motor division
ANS
Aka: Visceral motor division
Carries signals from CNS to effector;
Involuntary control
Sympathetic or parasympathetic
PNS sympathetic division
Fight or flight
PNS parasympathetic division
Rest and digest
PNS somatic motor division
Response to stimuli ; carry signal from CNS to gland/muscle
Voluntary muscle contraction
Nerves
Bundle of nerve fibers axons that are wrapped in fibrous connective tissues
Ganglia
Knot-like swelling And nerve weather cell bodies of peripheral neurons are located
Function of the nervous system
Stimuli—>Sensory—>CNS—>Effector—> until homeostasis 
Neuron
Major cell of nervous system; Response to environmental changes by transmitting signals in passing on electrical activity
Glial cells function
Maintain integrity of neural tissue
Provide protection
Increase conduction of nerves
Anatomy of neuron
Cell body/soma
Dendrites
Axon
Axon hillock
Terminal
Myelin sheath
Note of Ranvier
Dendrites
Tree like projections by cell body where receive signals from stimuli
Axon
long tail like extension of cell where electrical signal passes
Axon hillock
End of soma where action potential is triggered
Axon terminal
End of axon where neurotransmitters are stored
Myelin sheath
We are glial cells wraparound axon to insulate an increase Conductivity
Node of Ranvier
Gap in myelin sheath
Ratio of glial to neural cells
10 to 1
Glial cells of the CNS
Oligodendrocytes
Ependymal cells
Astrocytes

Oligodendrocytes
Octopus like; arms wrapped around multiple CNS neurons: provide insulation and speed up conductivity
Ependymal cells
Production and secretion of cerebral spinal fluid
Microglia
Tiny macrophages; Get rid of debris/dead tissue/foreign Matter
Astrocytes
Most abundant glial cell in CNS
-Has Periovascular feet that create blood/brain barrier
-monitors
Regulates blood flow
Provides nutrients
Removes waste
Regulatory composition
Protection and maintenance of environment
Which glial cell helps create the blood brain barrier?
Astrocytes and their perioVascular feet that wrap around vasculature
Glial cells of PNS
Schwann cells
Satellite cells
Schwann cells
Wrap around one axon To make myelin sheath and neurilemma
Satellite cells
Provide protection to someone in ganglia; regulate environment
Axonal transport
Neuro transmitters get to terminals on microtubules carried by motor proteins:
Anterograde transport protein= kinesins
Retrograde transport protein=
Dyneins
Afferent neuron
Sensory neurons that Send signals to CNS
Interneurons
Intermediate communication in CNS
Efferent neurons
Relay signal to effector from CNS
Neural transmitters get to axon terminals on ______ Carried by____ _____
Microtubules
Motor proteins
Motor proteins that carry cargo with Anterograde transport
Kinesins
Anterograde transport
Away from CNS
Motor proteins that carry cargo with retrograde transport
Dyneins
Retrograde transport
back to CNS
Presynaptic neuron
Neuron releasing neurotransmitter
Postsynaptic neuron
Neuron receiving signal
What percentage of neurons died during development?
70%
Plasticity
Allows neurons to continue to make new connections, memories, and learning (Prune, modify, and strengthen)
Regeneration of damaged PNS nerve fiber can occur if:
- Soma is intact
- At least some neurilemma remains
Steps of neural regeneration
- Exxon distal to injury degenerates
- Soma swells; Endoplasmic reticulum breaks up a nucleus moves off-center
- Axonstump sprouts
- Regeneration tube guides regrowth
How long does neural regeneration take?
Slow; two years; may not be perfect or possible. 
Can neurons in the CNS regenerate?
No, because they do not have Schwann cells