Blepharoptosis is drooping of the eyelids. Indicate whether ...

[Metfan725]

Blepharoptosis is drooping of the eyelids.
 
  Indicate whether the statement is true or false

Question 2

Explain how a muscle fiber contracts.
 
  What will be an ideal response?

[stillxalice]

Answer to Question 1

TRUE

Answer to Question 2

Each muscle fiber is connected to a single nerve cell at the neuromuscular junction. When the electrical impulse reaches the end of the nerve cell, the nerve cell releases the neurotransmitter acetylcholine. Acetycholine is a chemical messenger that moves across the neuromuscular junction and acts as a key to unlock receptors on the muscle fiber. This changes the permeability of the cell membrane and allows calcium ions to flow into the muscle fiber. Calcium ions cause the thin filaments to slide between the thick filaments, shortening the muscle and producing a muscle contraction.

[Metfan725]

Thank you

[stillxalice]

Happy to help you