The Digestion System Diagram Answers/Notes
1. Teeth: help chew food. Physical breakdown of food is mechanical digestion.
2. Tongue: helps mix food with saliva and pushes food down throat when swallowing.
3. Liver: Makes bile, a thick, mucus-like liquid that helps break down fats and lines the
small intestine (duodenum) to protect the small intestine from the stomach acid as food is
passed from the stomach into the intestines.
4. Gallbladder: stores the bile and secretes it into the duodenum.
5. Large intestine (colon): The large intestines compacts food particles and removes extra
water from the waste (feces). Attached to the Large intestines is the appendix, a vestigial
organ that has virtually no use for the human body anymore.
6. Small intestine: the longest part of the digestive system. It breaks down and absorbs fats
(lipids) and any other nutrients that have not already been absorbed into the blood stream.
Food passes from the stomach into the small intestine and then travels into the large
intestine.
7. Anus: The exit point for waste. Humans have a sphincter muscle here that controls when
waste is released. Humans and some other animals, such as dogs, pigs, and cats, have a
sphincter muscle. Farm animals such as horses, goats, cows, sheet, rabbits, and deer do
not have a sphincter muscle and cannot control their bowel movements. This is why they
do not make for a good house pet.
8. Mouth: the first part in digestion.
9. Salivary glands: glands are a part of the endocrine system, but they produce saliva that
mixes with food in the mouth making it easier to swallow. Saliva begins breaking down
food which is chemical digestion. Most of the sugar is absorbed through the mouth and
stomach.
10. Esophagus: The tube that travels from the mouth to the stomach.
11. Stomach: The stomach has hydrochloric acid that is about a pH 2 (very acidic). This acid
helps further break down food into much smaller, microscopic, pieces (chemical
digestion). Through peristalsis (churning of the stomach), the stomach contracts to help
further break down food (mechanical digestion). When the stomach passes food to the
small intestine (duodenum is the part where the small intestine and stomach meet), bile
lines to small intestine to prevent the stomach acid from burning the small intestine.
12. Pancreas: this is one of the largest glands in the body which is a part of the endocrine
system (hormones). The pancreas creates a hormone called insulin which controls the
blood glucose levels (sugar levels). The pancreas aids in digestion.