Stomach Anatomy Openings Gastroesophage al To esophagus Pyloric

Stomach Anatomy • Openings – Gastroesophage al: To esophagus – Pyloric: To duodenum • Regions – – Cardiac Fundus Body Pyloric

Stomach Histology: • Layers – Serosa or visceral peritoneum: Outermost – Muscularis: Three layers • Outer longitudinal • Middle circular • Inner oblique – Submucosa – Mucosa

Stomach Histology • Rugae: Folds in stomach when empty • Gastric pits: Openings for gastric glands – Contain cells

Small Intestine anatomy and Histology • Site of greatest amount of digestion and absorption • Divisions – Duodenum – Jejunum – Ileum: Peyer’s patches or lymph nodules • Modifications – Circular folds or plicae circulares, villi, microvilli • Cells of mucosa – Absorptive, goblet, granular, endocrine

Small Intestine Secretions • Mucus – Protects against digestive enzymes and stomach acids • Digestive enzymes – Disaccharidases: Break down disaccharides to monosaccharides – Peptidases: Hydrolyze peptide bonds – Nucleases: Break down nucleic acids • Duodenal glands – Stimulated by vagus nerve, secretin increases water and bicarbonate secretion from duodenal (Brunner's) glands

Duodenum

Liver • Lobes – Major: Left and right – Minor: Caudate and quadrate

Blood and Bile Flow

Pancreas

Small Intestine anatomy

Large Intestine • Cecum – Blind sac, vermiform appendix attached • Colon – Ascending, transverse, descending, sigmoid • Rectum – Straight muscular tube • Anal canal – Internal anal sphincter (smooth muscle) – External anal sphincter (skeletal muscle) – Hemorrhoids: Vein enlargement or inflammation