Neuromuscular Junction

Question 1

Neuromuscular junction:

Answer 1

WHERE AN AXON MEETS A MUSCLE FIBER

Question 2

Synaptic knob:

Answer 2

EXPANDED TIP OF AN AXON; LOOKS LIKE A FAN; HAS CALCIUM PUMPS

Question 3

Synaptic cleft:

Answer 3

NARROW FLUID-FILLED SPACE SEPARATING THE SYNAPTIC KNOB AND MOTOR END PLATE

Question 4

Motor end plate:

Answer 4

REGION OF SARCOLEMMA THAT HAS FOLDS TO INCREASE MEMBRANE SURFACE AREA COVERED BY THE SYNAPTIC KNOB

Question 5

Synaptic vesicles:

Answer 5

VESICLE THAT CONTAINS ACh

Question 6

Understand the sequence of events that occur at the neuromuscular junction that result in muscle contraction.

Answer 6

A) EXCITATION OF A SKELETAL MUSCLE FIBER: VOLTAGE CAUSES Ca2+ CHANNELS TO OPEN, RELEASING CALCIUM INTO THE PRESYNAPTIC TERMINAL, CAUSING VESICLES TO RELEASE ACh.
B) IN THE SYNAPTIC CLEFT, ACh BINDS TO ACh RECEPTORS, ALLOWING SODIUM TO ENTER SARCOPLASM, RESULTING IN DEPOLARIZATION.