Exam 1 - Neurophysiology

Question 1

Na+/K+ pump

Answer 1

3 Na+ molecules out for every 2 K+ molecules in

Requires ATP

Question 2

3 types of transport across membrane and functions

Answer 2

Passive: moves on its own concentration gradient

Gated: chemically gated, voltage gated

Active: requires energy to move ions against concentration gradient

Question 3

What is overshoot?

Answer 3

Inside of cell is positively charged relative to outside bc of depolarization

Question 4

What is undershoot?

Answer 4

Inside of cell is more negatively charged than resting membrane potential because of hyperpolarization

Question 5

What is absolute refractory period?

Answer 5

Na+ channels are closed for a period of time to prevent another action potential

Question 6

What is relative refractory period?

Answer 6

Na+ channels closed and K+ channels remain open causing further hyperpolarization. This makes it harder to generate action potential since the new potential is more than resting potential (afterhypolarization)

Question 7

Saltatory conduction

Answer 7

AP regenerated at Nodes of Ranvier

Question 8

Difference between spatial and temporal summation

Answer 8

Spatial - summation of potentials from different physical locations on cell

Temporal - summation of potentials closer in time

Question 9

Life cycle of synaptic vesicle

Answer 9

Budding -> filled with neurotransmitter -> docking/priming -> fusion -> NT release -> budding

Question 10

Ionotropic receptors

Answer 10

(ligand-gated channel receptors) have 4-5 subunits and at least 1-2 receptor-binding sites

Very fast speed of action

Question 11

Metabotropic receptors

Answer 11

(G-protein coupled receptor) have 1 subunit

Can alter G-protein gated ion channel or stimulate/inhibit an effector enzyme that synthesizes/degrades a second messenger

Very slow speed of action and long-lasting response