mod 5

Question 1

types of transport

Answer 1

simple diffusion, facilitated diffusion w carrier and w channel and active transport

Question 2

channel proteins

Answer 2

selective, many Na and K, moves down gradient.

Question 3

dendrites

Answer 3

receive signals, located at the branching tips

Question 4

axons

Answer 4

transmit signals, long part, does not contain organelles

Question 5

synaptic bouton

Answer 5

gap that connects to others, the end of axon that branches

Question 6

Nernst equation

Answer 6

for single ion, for relationship b/w an ion gradient and the equilibrium potential when membrane is only permeable to one ion.

Question 7

goldman equation

Answer 7

combined effects of ion on membrane potential

Question 8

goldman, lloyd and Katz

Answer 8

researchers describe how gradients of several diff ions contribute to membrane potential (goldman equation)

Question 9

depolarizing phase

Answer 9

Na channels open and action potential begin when neuron is depolarized by about 20mV. channels open from the helix S4 moving in an up position bc the inside is now more positive charged

Question 10

repolarizing phase

Answer 10

Na channels are inactive and k channels open

Question 11

hyperpolarizing phase

Answer 11

k channels remain open and Na close, and goes past resting (undershoots)

Question 12

what causes depolarization?

Answer 12

when dendrites receive a signal and spreads to the axon, action potentials only arise at nodes of Ranvier.

Question 13

myelination of axons

Answer 13

produced by schwann cells and olgiodendrytes, it acts as an electrical insulator, a cover. it reduces the membrane capacitance allowing Na to spread more down the membrane.

Question 14

how signal is transmitted

Answer 14

calcium channels open during depolarization and causes the fusion of secretory vesicle and release of neurotransmitter