Neuro

Question 1

how many pairs in sympathetic chain ganglia

Answer 1

21-23 pairs

Question 2

local potential

Answer 2

localised change in voltage across a membrane that doesn’t propogate an action potential. The magnitude of the voltage change is related to the strength of the stimulus. Therefore these events are regarded as both local and graded

Question 3

local potentials summation

Answer 3

The effect of local potentials on cell membrane potential is summed over both time (temporal summation) and space (Spatial summation)

Question 4

What are two types of refractory periods

Answer 4

absolute refractory period and relative refractory period

Question 5

absolute refractory period

Answer 5

another action potential cannot be propogated no matter how large the stimulus

Question 6

relative refractory period

Answer 6

another action potential can be propogated, provided the stimulus is large enough

Question 7

cause and purpose of refractory periods

Answer 7

caused by voltage channel inactivation and purpose is to stop APs from propogating backwards

Question 8

action potential definition

Answer 8

An action potential is a very brief increase in the permeability of the membrane to Na, followed by the termination of Na permeability and the brief increase in K permeability

Question 9

where does the spinal cord end

Answer 9

it ends at the inferior border of the 1st lumbar vertebrae

Question 10

how many segments in the spinal cord

Answer 10

31 segments