Exam 1 Flashcards
what is the basic division of labor in NS function
stimulus (sensory receptors) —->
Response (effector muscles)
what are the principle functions of glial cells
- Provide NS structure
- Produce myelin
- Maintain extracellular fluid
- BBB via endothelial cells
- repair and regeneration (microglia)
- NS development
- NS signaling
how do glial cells maintain extracellular fluid
a. regulate conc. of major ions
b. NT reuptake
how do glial cells help NS development
- guide neuronal migration
- secreting growth factors
- helping with axon pathfinding
how do glial cells participate in NS signaling
a. sense neuron activity via NT receptors
b. release NT and neuromodulators
c. pass signals to other glial cells
What is the Reticular theory
NS is a syncytium
Cytoplasm of nerve cells is continuous from one nerve to the next; Info not communicated between cells; Camillo Golgi
What is the Neuron Doctrine
Distinct cells
each neuron fully surrounded by its membrane; mechanism needed for info transfer; Santiago Ramon y Cajal
how did the golgi stain prove the neuron doctrine to be correct
Stain showed spacing in between cells
how is the inside vs outside of a cell defined
lipid bilayer
what are the requirements for an electrode for neuron recording
- Conducting tip
- Tip must be small
- Measure Vm only at tip
- material must not damage membrane; membrane must seal to it
- electrode should be filled with conducting solution
why is the membrane a good capacitor
cell membrane separated two conducting solutions making it a capacitor and the cell membrane is extremely thin giving it high capacitance (ions are closer together)
why is the cell membrane a good resistor
internal hydrophobic environment can resist movement of chrages
does thickness affect capacitance
no, only surface area and distance between plates
what are the two fundamental ion properties
- Regulated gating (voltage, ligand)
- Selective permeability
what is primary protein structure
linear sequence
what is secondary protein structure
local, repetitive spatial arrangements
what is tertiary protein structure
three dimensional of native fold
what is quaternary protein structure
non covalent oligomerization of subunits into protein complexes
what are the fundamental properties of Na(V) channels
gating regulated by Vm; Depolarization induces channel activation and delayed inactivation; selectively permeable to sodium ions
What is the physiological importance of Na(V) channels
generate depolarizations during action potentials
Describe sodium channels
permeable to sodium, AP depolarization, Excitability regulation; 1 subunit 4 domains; 6 TMR per domain; 1 p loop per domain
describe calcium channels
permeable to Calcium, transmitter release, enzyme activation, muscle contraction, 1 subunit 4 domains; 6 TMR per domain; 1 p loop per domain
describe potassium channels
permeable to potassium; AP repolarization, Excitability regulation; 4 subunits, 6 TMR per subunit, 1 p loop per subunit
what is the fundamental properties of nAChRs
gating is regulated by binding of ligands nicotine or acetylcholine; binding required after activation; permeable to cations
what is the physiological importance of nAChR
muscle nAChR mediate synaptic excitation at the NMJ; neuronal nAChR mediate synaptic excitation at some neuronal synapses
what are the fundamental properties of iGluRs
gating is regulated by binding of ligands such as Glu; required for channel activation; permeable to cations; composed of 4 subunits
what is the physiological importance of iGluRs
mediate vast majority of excitatory neurotransmission in vertebrates
