Digestive system: Anatomy and Disorders Part 3 Flashcards
What is the small intestine and its anatomy?
Main site for nutrient absorption
Structural modifications; increases surface area
-Circular folds in mucosa
-Villi (villus) cover the mucosa
-Microvilli cover the apical side of the epithelial cells (brush border)
How does the small intestine participate in chemical digestion?
Glands found in the intestinal walls; intestinal juice (water and mucus)
What are the enzymes on microvili?
-Peptidases (peptides –> amino acids)
-Maltase (maltose –> 2 glucose molecules)
-Sucrase (sucrose –> glucose + fructose)
-Lactase (lactose –> glucose +galactose)
What is the state in which carbohydrates are absorbed?
Monosaccharides
What is the state in which proteins are absorbed?
Amino acids
What is the state in which lipids are absorbed?
Free fatty acids & monoglycerides
Where do the macromolecules go after absorption?
-Monosaccharides and amino acids –> blood
-Glycerol and fatty acids enter lymphatic circulation; eventually blood
-Once in the ileum; chemical digestion is completed, and most nutrients are absorbed
What are the parts of the large intestine?
-Cecum
-Colon (ascending colon, transverse colon, descending colon)
-Rectum
-Anus
Smooth mucosa
What are the roles of the large intestine in absorption and defecation?
Absorption:
-Water
-Electrolytes (salts)
-Some vitamins
Indigestible remnants form the feces that enter the rectum:
-Nervous reflex causes defecation
-Involuntary and voluntary sphincters
What are the disorders of the large intestine?
-Diarrhea
-Constipation
-Appendicitis
-Colorectal cancer
What is constipation and its treatment?
Too much water absorption
Solutions:
-increase water and fibers intake; exercise
-laxative in last resort
What is diarrhea and its treatment?
Too little water absorption
Caused by:
-Bacterial or viral infections (e.g.: cholera)
-Stress (increases peristalsis)
Solution:
-decrease water and fibers intake
What is appendicitis and its treatment?
Appendix:
-role in community
-intestinal bacteria storehouse
Infection of the appendix:
-causes swelling and pain, may rupture
Solution:
-removal of the appendix
What is colorectal cancer and its treatment?
-Detected using colonoscopy
-Polyps (small tumors) can be cancerous or not
Colon cancer treatment:
-Colostomy (remove parts of the large intestine)
