Neural Transmission Flashcards
1
Q
Cells of NS
A
- Ramon y Cajal was the first to demonstrate that individual cells comprising the NS remained separate
- neurons contain membrane, nucleus, mitochondria, ribosomes, and endoplasmic reticulum
- sensory = afferent
- specialized at one end to be highly sensitive to a particular type of stimulation
- pseudo unipolar
- motor = efferent
- soma in spinal cord and receives excitation from other neurons and conducts impulses to muscles
-interneuron: dendrites and axons completely contained within a structure
2
Q
Glia
A
- major component of NS
- astrocytes: help synchronize activity of axon by rapping around presynaptic terminal and taking up chemicals released by axon
- microglia: remove waste material and other microorganisms that could prove harmful to neuron
- oligodendrocytes/schwann: build myelin sheath around axons
- radial glia: guide the migration of neurons and growth of axons and dendrites
3
Q
Ions and resting potential
A
-resting potential (-70mV) exists because ions are concentrated on different sides of the membrane
- Na+ and Cl- outside cell
- K+ and organic anions on inside
-forces of voltage and concentration are balanced for K+ and Cl- but not Na+
4
Q
Sodium-potassium pump
A
- membrane protein
- actively transports Na+ out of cell
- exchanges 3 Na+ for 2 K+
- maintains electrical gradient
5
Q
Anesthetic drugs
A
-block sodium channels and therefor prevent action potentials from occurring
6
Q
Saltatory conduction
A
- myelinated regions of axon are electrically insulated
- electrical charge moves along axon rather than across membrane
- action potentials occur only at unmyelinated regions: nodes of ranvier
- jumping of AP from node to node
- conserves energy
7
Q
Nerve anatomy
A
-every spinal and cranial nerve is surrounded and protected by connective tissue
- endonerium: wraps each neuron
- perineurium: covers nerve bundles called fascicles
- epineurium: covers fascicles
