Ch. 4, 5, 7, 8 based on slides

Question 1

Define Net Diffusion

Answer 1

Difference between 2 opposing movements

Question 2

Define Steady State

Answer 2

Equal movement of molecules in 2 opposite directions

Question 3

How do chemical messengers interact with cells & exert their effects?

Answer 3

Receptors that either open or close specific ion channels or generate a second messenger to trigger a series of intracellular responses

Question 4

Why does an AP flow in a unidirectional manner?

Answer 4

Because of the refractory period

Question 5

Latrotoxin (black widow spider venom)

Answer 5

Causes an explosive release of AcH thus sustaining contractions

Question 6

Botulinum Toxin

Answer 6

blocks the release of aCH leading to no muscle contractions

Question 7

Curare

Answer 7

Blocks nicotinic ach receptors preventing the activation of skeletal muscle

Question 8

Alpha- Bungarotoxin (Krait Snake Venom)

Answer 8

Binds to the ACH receptor sites (competitive inhibition) No contraction

Question 9

Organophosphates & Prostigmine

Answer 9

Inhibits acetylcholinesterase not allowing acH to be broken down and causing sustained muscle contractions. PREVENTS ACH BREAKDOWN

Question 10

Myasthenia Gravis

Answer 10

autoimmune disease, the body produces antibodies against ach receptors causing the muscle to not respond to ACH released

Question 11

Tetrotodotoxon (puffer fish)

Answer 11

Blocks the VG Sodium channels blocking AP’s in the axon

Question 12

Omega Conotoxin GVIA and Omega Agatoxin IVA

Answer 12

Both block VG CA channels in the presynaptic neuron not allowing for synaptic transmission