Lecture 19 - motility of GI Tract

Question 1

Where is skeletal muscle found in GI?

Answer 1

only in upper 3rd of oesophagus and lower large intestine

Question 2

How is skeletal muscle stimulated

Answer 2

motor neurons action potential leads to a release of ACh at cleft causing depolarisation of membrane, signal is propagated. Excitation caused by action potential will cause an influx in Ca2+, allowing further release of calcium from stores. It can then bind to contractile proteins to cause contractions. Calcium removed from cytosol for relaxation. The neurotransmitter is causing a change in excitation causing the cell to be excited.