Exam 1 Lecture 3/4 Flashcards
Resting membrane potential
-70mV
K: More intracellular (pumping in)
Na+: More extracellular (pumping out)
Cl-: More extracellular (Pumping out)
Energy sources of cells
-Fat/Glucose
-ATP
-Ion gradient (utilizes fastes)
Graded potentials
-Changes in membrane potential in response to incoming signals
-Changes can be depolarizing or hyperpolarizing
-Localized events
-Temporary/time specific
-Multiple neurons can add up
Eion K, Na, Cl
K: -90mV
Na: +60mV
Cl: -63 mV
Depolarizing
-Less negative
-Excititory (EPSP)
Hyperpolarizing
-More negative
-Inhibitory (IPSP)
Action potential
-Brief, rapid, and large depolarization of M.P
-Opening of voltage-gated ion channels
-55mV
Voltage gated Na+ channels
-Activation and inactivation gate
-Fastest responding channel
-Gate opens, Na in, Gate closes
Voltage gates K+ channels
-Activation gate (takes a while to close)
-Gate opens, K exits, Gate closes
Refractory period
-Time when A.P can’t fire
-Ensures A.P moves in one direction and non stop firing
Action potenital propagation
-A.P can only go from hillock to axon terminal direction
Permeability
-How easy it is for an ion to pass through membrane
-K highest (105)
-Cl (10)
-Na (5)
Axon hillock
-Location where it determines if A.P is fired
Synapse
-Place where both cells builds connection between neurons (chemical and electrical)
Electrical synapse
-Jump from 1 cell to another
-Little modification
-Less common
Chemical synapse
-2 cells close together
-Releases neurotransmitters
Neuron parts
-Dendrites
-Cell body (soma)
-Axon hillock
-Myelin
-Nodes of ranvier
Axon terminal
Voltage gates Ca2+ channels
-Open when A.P reaches synapse
-Ca2+ flows into cell
-Cause vesicles move to edge of membrane
NT release (after V.G Ca channels)
-Vesicles fuse to membrane and release NT into synaptic cleft
-NT bind to receptors
-Receptors activated
-Graded potential in new cell
-NT gets pumped out/inactivated
-NT sent back into cell to reuse
Myelination
-Increases speed of neural impulses
-Jumps to nodes of Ranvier
