Lectur 3,4 Flashcards
What are the 2 primary functions of neurons?
1.) rapid transmission of information from specific sources to selected targets: done via action potentials
2.) The integration of information / electrical activity from many sources
Anatomical structure of neurons?
Basis structure →
- cell body
- dendrites
-Axon
-Axon terminal
Define dendrites?
Receive info from other neurons
Define cell body
Contain nucleus & most cell organelles
Define axon hillock?
Information is collected by dendrites is integrated generating an action potential
Define axon ?
Conducts action potentials away from the cell body
Define axon terminal
Synapses with target cell
Define neurotransmitters?
The release of chemicals substances
The neuronal membrane at ‘rest’?
Cell is at rest = not generating an impulse / AP
Resting neurone →cytosolic side of plasma membrane has a negative electrical charge
Steady difference in electrical charge across membrane is called resting membrane potential ( RMP)
Define solutes?
Dissolved materials that con move across cell membrane and epithelia
Electrolytes → charged species: Na t k+ .
Conc of potassium ions is higher inside the cell vs outside whereas sodium & chionde Ians are more concentrated..
What does the phospholipid bilayerdo?
Separates ICF from ECF: forms a barrier
Water soluble ions
Membranes are selectively permeable to water, small molecules and ions pass through “special “ proteins
Define channel protein?
Ion channels: proteins assemble to form a pore
Ion selectivity
Gating
Ion pumps → nat/ki atlases
What does a carrier protein?
Used for glucose transport
Molecule binds to carrier
Carrier changes shape & molecule passes through
What is passive transport mechanism?
Transport ↓ the concentration gradient, or facilitated diffusion ( via channel/ carrier protein )
Can carry material only in direction of equilibrium
Define active - transport mechanism?
Transport against conc gradient; requires energy
→ primary & secondary
→ can carry material in direction opposing eqm
Movement of ions across membrane?
Direction of movement →
1.) concentration of gradient
Net movement of ions from a , region of high to a region of low concentration (down a conc gradients )
2.) charge of ions or molecule ( electrical gradient)
“Opposite charges attract like charges repel “
Electrical potential (V) reflects diff in charges
3.) The membrane potential (mv )
Inside surface of cell membrane is always negative compared to outside
What is neuronal resting membrane potential (RMP)?
Membrane potential: voltage across the national membrane.at rest inside neuron surface is electrically negative vs outside
Equilibrium potential: potential at which tendency of an ion to move ↓ its conc gradient is exactly balanced by the membrane potential0
Result: net movement of ion ceases → when electrochemical forces are equal & opposite
The Nernst equation?
Con calculate the equilibrium potential for a given ion