Chapter 3 Flashcards
What is neurophysiology
study of life processes of neurons
What is an ion?
atom or molecule that has an electrical charge by gaining or losing one or more electrctrons
What is an anion?
negatively charged ion (protein or chloride)
What is a cation?
a postivitively charged ion (potassium or sodium)
Explain the intracellular fluid and extracellular fluid
Intracellular is watery and found within cells; extracellular the fluid in the spaces between cells and in the vascular system
What is a cell membrane?
a lipid bilayer that ensheathes a cell
Whats a microelectrode?
small electrode used to record electrical potentials in cells
What is resting potential?
a difference in electrical potential across the membrane of a nerve cell
What is a millivolt?
a thousandth of a volt
What is an ion channel?
a pore in the cell membrane that alllows certain ions through
What is potassium K+
a potassium atom that carries a positive charge because it lost one electron
What is selective permeabilty
property of membrane that allows substances to pass through but not others
What is diffusion
Spontaneous spread of molecules until uniformed concentration is achieved
What is electrostatic pressure?
charged molecules or ions to move via diffusion toward areas with the opposite charge
What is a sodium potassium pump?
expensive mechanism that pushes sodium ions out of a cell and potassium in
What is a sodium ion Na+
sodium atom that carries a positive charge because it lost one electron
What is equilibrium potential?
movement of icons across the cell membrane is balanced, as the electrostatic pressure is pulling ions in one direction is offset by the diffusion force by pushing them in the opposite direction
What is the axon hillock?
area on the cell which the axon originiates
What is hyperpolorization/ depolarization?
increase in membrane potential (interior of of neuron)/ decrease in membrane potential
What is local potential?
electrical potential initiaed by stimulation at a specific site, decreasing with strength in time
What is threshold?
stimulus intenstiy that is adequate to trigger an action potentialat the axon hillcock