Exam 2 Flashcards
Nerve Fascicle
Many axons bundleed in connective tissue
What does a nerve consist of
A group of fascicles enclosed by a connective tissue covering
Nerves
A tissue; collections of neurons and associated cells (Glial cells)
Action potentials
Are rapid series of membrane depolarization events that move down the length of the neuron.
A membrane potential
is the seperation of charges across the plasma membrane.
What permits ion movement across a membrane?
ion Channels
What does electro-chemical gradient dictate
The tendency for an ion to flow across a membrane
Membrane potentials
Voltage differences that exist across a cell membrane.
What is the resting membrane potential.
The average neuron is about -70 mV
The membrane potential is established by what
Potasium and Sodiums leakiness across the membrane.
The membrane potential is maintained by what?
Na/K ATPase pumps
What is the Ration of Na/K pumps
3 Na out of the cell
2 K brought into the cell
Graded potential
Are localized changes in a cell’s membrane potential.
What does a depolarizing stimulus do?
Raises the membrane potential toward 0
What does hyperpolarizing do?
Lowers the membrane potential
