Herbivorous mammals don't secrete the enzymes required to digest cellulose. They sub-contract the work of cellulose digestion to guest bacteria. The bacteria are provided with a home and lots of food in exchange.
Humans don't do this. We have no capacity to digest cellulose. The appendix is the remnant of the Caecum in the human.
Stomach acid
Is it true that intestinal villi contains capillaries and lacteals important for chemical digestion?
Nope
No. An uncooked or undercooked burger contains microorganisms, but the burger itself is made from cattle, which are definitely not microorganisms.
Lysosomes
Lysosomes
Lysosomes
saliva is the substance in the mouth that contains enzymes to help with digestion before the food is swallowed.
Digestion is basically brought about by Enzymes, HCl, acid helps in killing bacteria :)
stomach
abdominal cavity
Digestion of food starts in the mouth. Saliva contains an enzyme that helps breakdown food.