Cells Of The Nervous System Flashcards
Define Glial Cell
Out number neurons by a factor of 10 to 50.
Provide physical and metabolic support
Assist in neuron repair, growth and protection
There are many types
Define Neuron
Cells that can transmit electrical signals
Neurons can have various morphologies
Axons of a single neuron can be quite long
Name two type of glial cells
Neurolemmocytes and oligodendrocytes
Neurolemmocyte
Are the glial cell of the PNS that produce myelin
Oligodendrocytes
Glial cells of the CNS that produce myelin
Neuron morphology:
What neurons are located in the CNS?
Multipolar and anaxonix
What type of neurons are located in the Efferent PNS?
Multipolar
What neurons are located in the Afferent PNS?
Bipolar and pseudounipolar
What do multipolar neurons look like?
Has multiple axons from one cell body with many dendrites.
What is an anaxonic neuron?
A neuron with no axon. And many dendrites come from the cell body.
What is the equilibrium potential for K+?
-94mV
What is the equilibrium potential for Na+?
-60mV
The Nernst equation at 37*C
E(ion)=(61mV/z)*log([ion out]/[ion in])
Z is charge of the ion
Out=ECF
In=ICF
What is he equilibrium potential of Ca++ ?
+99mV
What is the equilibrium potential of Cl-?
-89mV
What is resting membrane potential?
Has electrical potential of -70mV
Why is resting membrane potential negative?
Because k+ is 25 times more permeable to to the cell membrane. And flows out of the cell (efflux) such that it exceeds the influx on Na+ and a steady state is reached at -70mV.
Depolarize
Happens when the charge goes more positive from resting state
Hyperpolarize
Happens when the cell becomes more negatively charged from resting position
EPSP (Excitatory Postsynaptic Potential)
Equivalent to a depolarizing Graded Potential
Conduction velocity is dependent on what 2 characteristics of the neuron?
Presence of myelinated motor axons and diameter of axons (increased/fat increase velocity)
What are 2 demyelination diseases? And how do they effect the body?
Multiple sclerosis: autoimmune destruction of oligodendrocytes. And adrenoleukodystrophy: loss of neuronlemmocytes from somatic motor neurons. (Only boys)
Anatomy of a synapse
Presynaptic membrane Postsynaptic membrane Synaptic cleft Neurotransmitters Receptors on Postsynaptic membrane
ACh is degraded by what enzyme?
Acetylcholinesterase (AChE)
Why are neurotransmitter half lives small?
They must be short because they I control muscle contractions and other parts of the body that must quickly act and react?
What are the 3 types of synapse?
Neuron-neuron
Neuron-muscle (neuromuscular)
Neuron-gland junction
What is synesthesia?
Confusion of senses
What are the 4 characteristics of sensory?
Nature
Location
Duration
Intensity
