Do NowDo Now: Homeostasis is the maintenance of relatively stable internal physiological conditions (as body temperature or the pH of blood) in higher animals under fluctuating environmental conditions. How can homeostasis be disrupted in the human digestive system?

AimAim: What are the causes and effects of some disorders of the human digestive system?

I. Digestive System DisordersDigestive System Disorders

Think about the main function of the large intestine. What would happen if the large intestine did not perform its main function properly?

A. DiarrheaDiarrhea - loose, watery stools occurring more than three times in one day.

1. Causes include viral, bacterial, or parasitic infections; food intolerance (ex: lactose in milk); and reactions to medicine. All of these may cause the large intestine not to reabsorb enough water back into the body.

How can chronic (of long duration) diarrhea affect someone?

B. ConstipationConstipation - constipation means hard stools, difficulty passing stools (straining), or a sense of incomplete emptying after a bowel movement.

1. Theoretically, constipation can be caused by the slow passage of digesting food through any part of the intestine, (mostly the colon) causing more water than usual to be absorbed.

C. UlcerUlcer – an open sore that can occur in the lower esophagus, stomach, and most often in the upper portion of the small intestine (duodenum).

Ulcer locations

Why do ulcers hurt?

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hint

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1. Today, research shows that most ulcers develop as a result of infection with bacteria.

a. Bacteria damage the protective lining of the stomach.

2. Lifestyle can also fuel an existing ulcer.

a. smoking, drinking alcohol, stress, and consuming caffeine can increase the chances of getting an ulcer.

D. AppendicitisAppendicitis - is an inflammation of the appendix.

1. Appendicitis occurs when the interior of the appendix becomes filled with something that causes it to swell, such as mucus, stool, or parasites. The appendix then becomes irritated and inflamed. It can become deadly if not treated immediately.

Inflamed appendix

If the appendix has no true life function, why is it dangerous if it is inflamed or ruptured?