Functions of the Large Intestine

Causes of Obesity

• Heredity, eating habits, inadequate exercise, and poor diet contribute to obesity.
• Excess kilocalories are stored as fats in adipose tissue.
• Consuming fewer kilocalories than needed helps mobilize and break down stored fat.
• Exercise increases energy needs, helping to burn fat more rapidly.

Glucagon-like Peptide-1 (GLP-1)

• Produced by cells of the small intestine.
• Stimulates insulin secretion and inhibits glucagon secretion.
• Slows gastric emptying and reduces food intake.
• Receptors are expressed in many brain regions.
• Semaglutide is a GLP-1 receptor agonist.

Inflammatory Disorders

• Periodontal disease: inflammation, bleeding gingivae, and degeneration of gingivae, cement, periodontal ligaments, and dental alveoli.
• Peritonitis: acute inflammation of peritoneum due to bacterial contamination.

Noninflammatory Disorders

• Constipation: difficult defecation due to hard, dry feces.
• Diarrhea: production of watery feces due to rapid peristalsis in the colon.
• Eating disorders: obsessive concern about weight control, including anorexia nervosa and bulimia.

Obesity

• Results from consuming more kilocalories than needed to meet energy needs.
• GLP-1 stimulates insulin secretion, inhibits glucagon secretion, and slows gastric emptying.
• Semaglutide is a GLP-1 receptor agonist.

Large Intestine

• Chyme enters the large intestine through the ileal orifice.
• Consists of four segments: cecum, colon, rectum, and anus.
• The anus is kept closed except during defecation by the internal and external anal sphincters.
• Taeniae coli are three longitudinal bands of muscle running the length of the colon.
• Mucosa possesses no villi, and epithelium contains numerous goblet cells.

Absorption of Carbohydrates and Fats

• Simple sugars are absorbed across the epithelium and into capillaries of the intestinal villi.
• Fats are absorbed by simple diffusion, and bile salts interact to form micelles.
• Micelles absorb large fatty acids, monoglycerides, cholesterol, phospholipids, steroids, and lipid-soluble vitamins.

Disorders of the Digestive System

• Inflammatory disorders: appendicitis, diverticulitis, and peritonitis.
• Noninflammatory disorders: constipation, diarrhea, and eating disorders.

Liver

• Largest gland in the body, located below the diaphragm.
• Dark, reddish-brown color, with a falciform ligament that joins it to the diaphragm and anterior abdominal wall.
• Main lobes are the right and left lobes.

Small Intestine

• Mucosa has numerous intestinal villi, increasing surface area.
• Villus anatomy includes a lacteal and a blood capillary network.
• Microvilli increase surface area, with tiny pits at the base of villi opening into intestinal glands that secrete intestinal juice.

Intestinal Juice

• Slightly alkaline, with abundant water and mucus, forming an environment for bile salts and pancreatic digestive enzymes.
• Regulated by mechanical stimulation and neural reflex due to intestinal wall stretch caused by chyme.

Learn about the main functions of the large intestine, including the absorption of water and vitamins, and the production of feces. Discover the types of movements that occur in the large intestine and how often they happen. Test your knowledge of this important part of the digestive system!