This is a muscular tube through which food passes, aided by peristaltic contractions, from the pharynx to the stomach.

The rh factor identifies the presence of the rhesus protein in blood. the rh factor can be represented by a + or – sign. it is important to know the rh factor because just like how the antigens on the blood must be compatible, the rhesus protein in blood must also be compatible. if a person has rh+ blood they can blood. answer c. rh+ or rh-