i think its mucus or something similar
Cells and muscles.
Smooth muscle lines most of the digestive system, especially the intestine.
The stomach has the greatest protection against acid due to a thick mucous layer that lines its walls, which helps protect the stomach lining from being damaged by the acidic digestive juices.
digestive system is lined inside by non-keratinised stratified squamous epithelium some of which are ciliated
The bacteria that lines the inner stomach breaks down and makes the foods digestive, regardless of the acid it contains.
PeristalsisPeristalsis
The membrane that covers the organs of the digestive system like a curtain is called the peritoneum. It lines the abdominal cavity and helps support and protect the digestive organs.
Anatomy starts at the cellular level. (I'm going to use the digestive track for this example) First there are cells. Cells make up tissues (such as the tissue that lines the inside of your stomach). An accumulation of different tissues then makes an organ (ie. your stomach). An organ system would be a group of organs that work together, in this example it would be the digestive track: esophagus ...stomach...small intestine...colon..etc. And then finally, a group of organ systems makes up an organism, which would be you or me, a human!
The integumentary system includes your skin, and mucus that lines your stomach, intestines, and rectum.
Peristalsisis a radially symmetrical contraction and relaxation of muscles which propagates in a wave down the muscular tube, in an anterograde fashion. In humans, peristalsis is found in the contraction of smooth muscles to propel contents through the digestive tract. Earthworms use a similar mechanism to drive their locomotion.[1] The word is derived from New Latin and comes from the Greek peristallein, "to wrap around," from peri-, "around" +stallein, "to place".
The serous membrane in the digestive tract is known as the peritoneum. It lines the abdominal cavity and covers abdominal organs, providing protection and support while allowing for movement and flexibility in the digestive system.
The epiglottis covers the esophagus. The epiglottis is a small flap that covers the epiglottis when breathing and covers the trachea, or windpipe, when you are eating to prevent food from entering the lungs.