Ch. 8 Neurons Flashcards
Glial cells of PNS
Schwann cells
Satellite cells
Schwann cells
Form myelin
PNS
Satellite cells
Non-myelinated cells, cluster around cell body
PNS
Glial cells of CNS
Oligodendrocytes
Astrocytes
Microglia
Ependymal cells
Microglia
Immune cells
Keep out infection
CNS
Oligodendrocytes
Form myelin
CNS
Astrocytes
Branched cells, communicate via gap junctions
CNS
Ependymal cells
Create epithelial barriers
Source of stem cells
CNS
Structural Classes of Neurons
Psuedounipolar
Bipolar
Anaxonic
Multipolar
Psuedounipolar
Dendrites fused with axon
Structural class
Axon Hillock
Region where the axon originates from
Bipolar Neuron
2 fibers extending from 1 cell body
Structural class
Anaxonic
No apparent axon
Structural Class
Multipolar Neuron
Branched but no long extensions
Structural Class
Functional Classes
Sensory Neurons
Interneurons
Efferent Neurons
Sensory Neurons
Collect info from the body
-Afferent
Functional class
Interneuron
Sensory reflexes
Functional class
Efferent neurons
Communicate from CNS to body tissues
Functional class
Graded Potential
small stimulus that may only travel a short distance but may become an action potential
Subthreshold and suprathreshold action potential
- Fades and dies
2. Causes action potential
Depolarization
Cell becomes more positive
Hyperpolarization
Cell becomes less than -70mV
Start of action potential
-55mV
Non-myelinated axons
Signal travels as a wave
Myelinated axons
Signal jumps b/w nodes of Ranvier
Hyperkalemia
Depolarizes membrane
Easier to reach threshold (nerves respond to lesser stimuli)
Hypokalemia
Hyperpolarizes membrane
Harder to reach threshold
Chemical Synapses
Connected via adhesion junctions
Neurotransmitters
Can stimulate or inhibit post synaptic cell
-CA entry into cell triggers exocytosis of synaptic vesicle content
