2. In the human digestion process, solid food is broken down to smaller pieces by chewing and then is digested by various digestive enzymes (eg: amilase, pepsin, lipase) when food is moved through the alimentary canal by peristalsis.
3. Absorption of the digested food occurs in the ileum. Digested is also completed in the ileum
4. Products of digestion, such as simple sugars, vitamin B and C, amino acids and minerals are absorbed into the blood capillaries by diffusion.
5. These substances are transported by the hepatic portal vein into the liver and then are distributed by the circulatory system to the whole body.
6. Other products of digestion (fatty acids, glycerol, vitamins A, D, E and K) are absorbed into the lacteal (lymphatic vessel) in the illus.
7. These substances are transported through the thoracic duct and return to the bloodstream via the left shoulder vein.
8. Undigested materials form faeces. This is then egested through the anus. This process is called defecation.
9. Humans cannot digest cellulose. Ruminants have a four-chambered stomach and rodents have a large caecum ; both of which contain microorganisms that secrete the enzymes cellulose to digest cellulose.
10. List of organs involved in the digestion of food.
-Tooth : organ set in the jaws and used to cut and crush food.
-Tongue : organ of taste.
-Pharynx : part of the digestive tract between the mouth and the esophagus.
-Esophagus : part of the digestive tract between the larynx and the cardia of
the stomach.
-Stomach : pocket-like part of the digestive tract, where food is mixed and
stored.
-Pancreas (tail) : gland connected to the digestive tract which produces digestive
enzymes.
-Duodenum : beginning of the small intestine.
-Small intestine : part of the digestive tract between the stomach and the large
intestine.
-Descending colon : part of the large intestine in which food travels downward.
-Sigmoid : last part of the descending colon.
-Anus : end of the large intestine, through which the human body expels
solid waste.
-Rectum : last part of the large intestine, between the sigmoid colon and the
anus.
-Appendix : hollow diverticulum fastened to the caecum.
-Cecum : blind gut formed by the part of the large intestine between the
small intestine and the ascending colon.
-Ascending colon : part of the large intestine where food travels upward.
-Transverse colon : part of the large intestine where food travels horizontally.
-Gallbladder : small sac that contains the bile.
-Liver : digestive gland that produces bile.
