Functional Classification of Joints

Question 1

Synarthroses

Answer 1

Immovable

Question 2

Amphiarthroses

Answer 2

Slightly movable

Question 3

Diarthroses

Answer 3

Freely movable joints

Question 4

Step 1

Answer 4

Action potential arrives at axon terminal motor neuron

Question 5

Step 2

Answer 5

Voltage-gated Ca2+ channels open. Ca2+ enters the axon terminal, moving down its electrochemical gradient

Question 6

Step 3

Answer 6

Ca2+ entry causes Ach (neurotransmitter) to be released by exocytosis

Question 7

Step 4

Answer 7

Ach diffuses across the synaptic cleft and binds to its receptors on the sarcolemma

Question 8

Step 5

Answer 8

Ach binding opens ion channels in receptors that allow simultaneous passage Na+ into muscle fiber and K+ out of the muscle fiber; more Na+ ions enter K+ ions exit (local change in membrane potential — end plate potential)

Question 9

Step 6

Answer 9

Ach effects are terminated by its breakdown the synaptic cleft by acetylcholinesterase and diffusion away from the junction