Digestive system review key:

Describe the digestive system?

Includes the mouth, esophagus, stomach and intestines which break down food mechanically and chemically into molecules to be absorbed into the blood stream and distributed to the cells.

Describe functions of the digestive system.

  • Digestion starts in the mouth where teeth rip, tear, and mash food into smaller pieces (mastication) and mix it with the first digestive secretion, saliva.
  • Saliva is produced in the salivary glands and is an enzyme that chemically changes starches and sugars into smaller particles.
  • Stomach receives food it is mixed with gastric juices and digested into a fluid, chyme, a mixture of food and digestive juices. Some nutrients are absorbed in the stomach and into the bloodstream (alcohol).
  • Peristalsis moves the digested fluid past the pyloric sphincter muscle at the bottom of the stomach and into the duodenum, the beginning of the small intestine.
  • Small intestine absorbs nutrients into the blood stream. Chyme leaves the stomach through the pyloric sphincter, enters at the top, duodenum, where it is mixed with more digestive juices (bile form the gallbladder and pancreatic juices from the pancreas) that enter through the bile duct. The small intestine walls excrete enzymes that further the digestion so nutrients enter the blood stream through the villi.
  • Undigested and unabsorbed materials move from the small intestine to the colon that absorbs water, salts, vitamins, iron, and eliminates the waste (unabsorbed material left), which is stored in the rectum and eliminated through the anus..

Parts and functions

Match the words in the word bank to the function and label the diagram.

  1. ___ epiglottis _________ prevents food from entering the respiratory system.
  2. ___ peristalsis ________ muscle movement that moves food through the entire digestive tract.
  3. ___ saliva ___________ discharge into the mouth that begins digestion.
  4. ___ heartburn ________ a burning discomfort in the upper abdomen, chest, or below the breast bone.
  5. ___ tongue ___________ helps move food in the chewing swallowing process.
  6. ___ esophagus _________ connects the mouth to the stomach.
  7. ___ small intestine ______ undigested and unabsorbed materials move through and into the colon.
  8. ____ liver ____________ makes bile that breaks down fats for absorption.
  9. ____ rectum __________ stores solid waste until it is eliminated.
  10. ___ villi ______________ small projections in the small intestine lined with capillaries that absorb nutrients and minerals from food.
  11. _____ mucus __________ substance secreted by the stomach walls that somewhat protects the stomach wall from gastric juices digesting it.
  12. ___ gall bladder _________ stores bile.
  13. ___ uvula _____________ tissue at the top back of the mouth that keeps food from entering the nasal cavity.
  14. ___ esophageal sphincter ___ muscle at the entrance of the stomach that keeps gases and liquids from moving up the esophagus.
  15. ___ gastric juices ________ liquid secreted from the stomach walls to digest food.
  16. ___ stomach ___________ digestive organ between the esophagus and small intestine.
  17. ___ salivary glands _______ produce saliva.
  18. ___ anus ______________ the end of digestion.

Label parts on the diagram


Digestive system diagram

Word bank

anus, gastric juices, heartburn, villi, blood vessels, esophagus, tongue, saliva, salivary glands, esophageal sphincter, rectum, small intestine, colon, uvula, epiglottis, peristalsis, mucus, stomach, liver, gall bladder,

Describe ways to care for the digestive system.

  • Eat slow and chew food well.
  • Drink at least 64 ounces of water daily (8-8 ounces or 5 1/2-12 ounces).
  • Eat healthy, low fat, high fiber.
  • Wash your hands.
  • Use safe food preparation and storing techniques (cool, clean, cook, & separate).
  • Visit a health professional regularly or as a need may arise.

Describe health related care issues for the digestive system.

  • Heartburn is a burning discomfort in the upper abdomen, chest, or below the breast bone. The lower esophageal sphincter (LES) opens when belching or to let food move from the esophagus to the stomach and closes to keep stomach acid in the stomach. However, if it opens too often or does not close tightly, stomach acid can reflux, or seep, into the esophagus and cause a burning sensation. Heartburn can be caused by too much food in the stomach (overeating), too much pressure on the stomach (being over weight, pregnant, or constipated) or foods that relax the lower esophageal sphincter (tomatoes, citrus fruits, garlic, onions, chocolate, coffee, alcohol, caffeinated products, and peppermint). Foods with a high percentage of fats and oils and some medications can increase discomfort. Stress and lack of sleep can increase acid production and can cause heartburn. Smoking, both relaxes the sphincter and stimulates stomach acid. Reduce stress, control diet by not eating foods that contribute to increased acid or relaxes the LES. Medication or in serious cases surgery.
  • Constipation is when the solid waste (feces) becomes hard and dry making bowel movements difficult. Exercise, drink sufficient water to soften, and eat sufficient fiber to move waste through the digestive system. Consult with medical experts to review the use of medication (antidepressants), vitamin supplements (large doses of calcium, iron), or diet (too much dairy ... not enough fiber) that may be the cause constipation.
  • Indigestion is the feeling of discomfort in the upper abdomen sometimes with nausea and gas. Can be caused by eating too much, too fast, too much fat, spicy foods, or stomach disorders or stress. Change eating habits and if problem continues, consult a medical professional.
  • Stomach ache and nausea can be caused by gas, motion sickness, bacteria, virus, medication, and dehydration.
  • Diarrhea is frequent watery feces. Can be caused by medication, stress, bacteria, virus, lactose intolerance, parasite, or nutritional deficiencies. Dehydration can occur along with it. Drink plenty of fluids and if there is a high fever, sever pain, black or bloody stool, or it persists consult a medical professional.
  • Appendicitis is inflammation of the appendix caused by blockage or bacterial, viral, or fungal infection. Symptoms may include dull or sharp pain anywhere in the upper or lower abdomen, back, or rectum, fever, nausea, and vomiting. Consult a medical professional. Lack of timely treatment can result in death if the infection spreads.


Dr. Robert Sweetland's notes
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