Lecture 5: Neuromuscular Junction

Question 0

Synaptic Gutter (Trough)

Answer 0

Groove on surface of sarcolemma where axon terminal makes contact

Question 1

Dense Bars

Answer 1

Anchored to presynaptic membrane and tethered to synaptic vesicles by short filaments

Question 2

Subneural Cleft

Answer 2

Smaller grooves in the bottom of the gutter to increase surface area

Question 3

How is an end-plate potential created?

Answer 3

Through large numbers of Na+ ions passing into the muscle fiber

Question 4

What drugs have the same effect on muscle fiber as Ach, but are not broken down and cause spasms

Answer 4

Nicotine, Metacholine, & Carbachol

Question 5

What drugs inactivate Ach-esterase and cause spasms?

Answer 5

Neostigmine, Physostigmine, & Diisopropyl Fluorophosphates

Question 6

What does Curare do?

Answer 6

Prevents the passage of impulses from nerve to muscle

Question 7

What is Myasthenia Gravis?

Answer 7

An autoimmune disease that attacks Ach receptors that doesn’t allow a strong enough end plate potential to be created to initiate an action potential