esophagus

Question 1

esophagus function

Answer 1

Moves food from pharynx through the esophagus to the stomach using peristalsis
Secretes mucus to help move food

Question 2

esophagus epithelium lining

Answer 2

Lined with folded stratified squamous epithelium – stretches when food goes down.
Stratified squamous epithelium also protects esophagus from wear and tear by food

Question 3

muscle layers of the esophagus

Answer 3

Muscularis layer consists of two muscle layers in different directions (longitudinal and circular) – for peristalsis
First third of esophagus is skeletal muscle (not voluntary!) to move food quickly.
Last two thirds smooth muscle – contracts slower

Question 4

what is peristalsis

Answer 4

Peristalsis is a process which occurs to move food (bolus) along the alimentary canal.

Question 5

steps of peristalsis

Answer 5

Behind the bolus the circular muscle contracts to form a constriction.
Circular muscle around and in front of the bolus relaxes.
By contraction of successive bands of circular muscle, the constriction moves in a wave along the oesophagus, pushing the bolus in front of it.
Movement of the bolus is lubricated by mucus secreted by the lining of the oesophagus.