The rhythmic contractions of the esophagus that moves food forward is

The sphincter between the stomach and the small intestine is the

The following structure is involved in equalizing pressure in the middle ear

The islets of Langerhans are the endocrine portion of the 

If an elastic ball is thrown horizontally and bounces off of a wall, it travels straight back due to a change in momentum of

The prominent folds of the mucosa that nearly disappear when the stomach expands are the ______________.

The muscle which changes the shape of the lens by pulling on the ligaments

A structure that has lost its original function through evolution but provides history of the ancestor that needed that structure to function is known as ______

All of the following are extraembryonic membranes except 

A person with blood type A+ has the following _________.