The Small Intestine

SMALL INTESTINE Site of digestion and absorption of proteins, fats and carbohydrates. INTESTINAL JUICE AMOUNT: 3L/DAY pH: 7.6 Water: 98% Solids:1.5% Organic and inorganic ions Enzymes: enterokinase Proteolytic enzymes Sucrase Intestinal Lipase Cholesterol esterase Lecithinase Secretion of intestinal juice depends on local and mechanical factors Carbohydrate digestion: Sucrose is split into

Glucose and fructose by sucrase

Lactose is split into glucose and galactose by lactase Fat digestion: FATS →→→Triglycerides→→→→Diglycerides→→→Monoglyceride LIPASE

LIPASE

LIPASE

Protein digestion: Peptones and polypeptides are broken down into aminoacids by enzyme erepsin Movements of small intestine: Rhythmic movements Peristaltic movements Rhythmic movements arise at regular interval along the gut by increase in calcium influx. Initiated by pacemaker cells in second Part of duodenum. Movements are increased by GIT HORMONES. GASTRIN CCK PZ. MOTILIN DECREASED BY: SECRETIN GLUCAGON. PERISTALSIS: Wave like contractions along the length of small intestine. Waves propel chyme towards distal part. Rate of peristalsis: 2-25 cm/sec.

APPLIED ADYNAMIC ILEUS Painless condition due to trauma causing direct inhibition of smooth muscle leading to decreased intestinal motility.