Upon Completion of This Unit the Student Will

Name______Date______

Key Idea #2 – Outline 1Living Environment: Mrs. Abrigo

Upon completion of this unit the student will:

1. define the terms nutrition, ingestion, digestion, autotroph, and heterotroph.

2. define the terms micronutrient and macronutrient.

3. list four categories of macronutrients and explain their chief functions in the body.

4. list two categories of micronutrients.

5. list four factors which influence the nutritional requirements of humans.

6, explain the composition of roughage (fiber) and list some reasons the body needs this.

7. recognize that carbohydrates should provide at least 50% of the energy needs of

the body.

8. list the hydrolytic breakdown products of complete carbohydrate, protein, and lipid

digestion, as well as the enzymes facilitating this process.

9. state two other names for the GI (gastrointestinal) tract.

10. state the chief role(s) of the following in the human digestive process; mouth, oral cavity,

tongue, teeth, and salivary glands.

11. define the term peristalsis and recognize that it begins in the esophagus in humans.

12. describe the role of the epiglottis and esophagus in human digestion.

13. describe the appearance and role of the stomach in human digestion.

14. describe the roles of pepsin (gastric protease) and HCl in the stomach.

15. recognize it is the job of the liver to make bile and the gall bladder to temporarily

store bile.

16. recognize the function of bile is to emulsify lipids in the small intestine.

17. define the term emulsification.

18. describe the role of pancreatic juice in the digestive process in the small intestine.

19. explain how bile and pancreatic juice are carried to the small intestine.

20. describe the role of intestinal juice in the small intestine.

21. discuss the role of the folding of the small intestine and the villi which line its surface.

22. recognize that the appendix is a vestigial structure in humans.

23. state the chief function of the large intestine, rectum, and anus in humans.

24. define the term defecation.

25. given a diagram of the human digestive system, label the major organs of the system.

26. list the chief symptom(s) and/or cause of the following digestive disorders; ulcer,

appendicitis, gallstones, constipation, and diarrhea.

I. Nutrition--process by which organisms obtain and utilize their food

2 Parts:

1. ingestion-

2. digestion-

Terms to know:

Autotrophs-

Heterotrophs-

nutrients-

micronutrients-

macronutrients-

** Water, vitamins, and minerals are small molecules that can be absorbed without digestion. (hydrolysis)

** Large molecules like carbohydrates (starches), lipids, and proteins require digestion.

-Carbohydrates (sugars and starches) should constitute 50% of the energy for the body. They provide the major source of energy for the body.

-Carbohydrates are found in fresh fruits and vegetables as well as whole grains.

-Complex carbohydrates provide a source of nondigestible materials which increase the amount of ROUGHAGE (also called "fiber"--stimulates the muscles of the alimentary canal or food tube)

-calorie --

Obviously the calorie value of different types of food varies.

** Nutritional requirements, including energy (caloric needs), vary with the human:

1.)

2.)

3.)

4.)

5.)

** Fats contain more potential energy per each unit of their mass then any other major nutrient.

MECHANISM FOR CHEMICAL DIGESTION

Hydrolysis--the splitting of large, insoluble molecules into small, soluble molecules with the addition of water

** In organisms, this process is regulated by hydrolytic (digestive) enzymes and is illustrated by the following:

1. Maltose + water ----> simple sugars (glucose for instance)

2. Proteins + water ---> amino acids

3. Lipids + water ---> 3 fatty acids + glycerol

** In a similar fashion, polysaccharides such as starch, are completely hydrolyzed to simple sugars.

Human digestive tract = GI (gastrointestinal) tract = alimentary canal

peristalsis-

Mouth-

Oral cavity-

Teeth-

Salivary glands-

2 Facets of Saliva:

Tongue--

Secretion of saliva is stimulated automatically. (conditioned reflex)

Esophagus--

Stomach—

Gastric juice--components and their functions

1. Water--

2. Mucus--

3. Hydrochloric acid (HCl)—

4. Pepsin--

Pyloric sphincter—

** Food is usually held 2-4 hours in the stomach.

Small intestine:

--accessory structures, the gall bladder and the pancreas, empty their secretions into the SI

LIVER--

Gall bladder--

Bile duct--.

Bile emulsifies lipids--

Pancreas—

** Pancreatic juice digests all major nutrient types.

Nearly all digestion occurs in the small intestine & all digestion is completed in the SI.

Intestinal glands—

(Absorption in the SI)

Much absorption is thought to occur directly through the wall without the need for special adaptations.

villi—

Large Intestine

appendix--

** Undigested food and water enter the large intestine where water is absorbed. Strong peristaltic action forces feces out through the rectum and

the anus.

defecation--

The Human Digestive System (diagram)

(Some Digestive Homeostais Disorders)

Ulcers—

Constipation—

Diarrhea—

Appendicitis—

Gallstones—