The stomach and the cells that comprise it have a three-part protection system to protect from the acid contained in the stomach, comprised mostly of compact cell unions.
The stomach is one of the main digestive tract organs. Its job is to break down the food we ingest and pass it along to the rest of the digestive tract. To perform this action, the stomach secrets hydrochloric acid. However, the stomach itself is not damaged by this acid due to a three-part protective system comprised of:
Tight epithelial cell lining
Mucose Barrier
Bicarbonate secretion
The cells present in the epithelial lining of the stomach join one another via compact cell unions to form a closed barrier which is then covered by a thick Mucose barrier. This along with the secretion of bicarbonate which works to break up the acids present in the stomach and ingested, form a sealed barrier that protects the stomach from harm.
Plants show immediate growth, animals do not at first. The cells of plants differ immediately, whereas this is not the case with animals. Animals bend inwards and make a body cavity and plants do not form an inner space.