吉林大学基础医学院：《组织学与胚胎学》课程教学课件（讲稿）小肠 Small intestine

Small intestine Divided into three parts: duodenum jejunum ileum Function: *digestion *absorption secreted certain hormones

Small intestine Divided into three parts: duodenum jejunum ileum Function: *digestion *absorption *secreted certain hormones

Mesentery Plica Mucosa Submucosa Circular- muscle 美集 Longitudinal muscle Serosa Submucosal glands i

Vein carryin hepatic port Muscle layers Lumen Large circular folds Villi (a) Plicae circulares a fold of mucosa and submucosa in the lumen of digestive tract

Plicae circulares : a fold of mucosa and submucosa in the lumen of digestive tract

Intestinal villi *small finger-or lea found only in the s Absorptive cells Lacteal *varying in the forr Goblet ce *being covered by e Blood capillaries *having a core of la capillary network, few smooth muscleestinal crypt iscularis mucosae odenal glands Subn

*small finger- or leaf-like projection of the mucosa, found only in the small intestine; *varying in the form and height in different region *being covered by epith. *having a core of lamina propria with capillary network, a central lacteal and few smooth muscle fibers. Intestinal villi

microvilli: the minute projections (1 um long and about 0.1 um wide)of cell membranes Microvilli The inner surface of small intestine can be greatly enlarged by: plicae circularesX 3. villiX 10. microvilliX 20

microvilli: the minute projections (1 µm long and about 0.1 µm wide) of cell membranes The inner surface of small intestine can be greatly enlarged by: * plicae circularesX 3. * villiX 10. * microvilliX 20

Jejunum H&E lumen villi with simple columnar epithelium jejunum

jejunum

H.E.staining 模式图 Core of villus. epithelium villus Smooth muscle gland Artery Lacteal vein Longitudinal section of small intestine

gland epithelium villus Core of villus Artery Lacteal vein Longitudinal section of small intestine H.E. staining 模式图 Smooth muscle

5.1.1 Epithelium Simple columnar epith. 5.1.2 lamina propria C.T.containing lymphatic tissue,solitary lymphatic nodule,intestinal glands. protrudes into the lumen together with epithelium to form villi

5.1.2 lamina propria * C.T. containing lymphatic tissue, solitary lymphatic nodule, intestinal glands . * protrudes into the lumen together with epithelium to form villi . 5.1.1 Epithelium * Simple columnar epith

Villi Lymphatic Smooth capillary muscle Vein Artery Lymphoid Intestinal nodule glands 小小 Lamina propria Muscularis mucosae Submucosa Submucosal plexus Muscular- layer (inner) Myenteric plexus Muscular- Serosa layer (outer)

Small intestinal gland *infolding the epithelium to the lamina propria at the base of villus *types of cells: Goblet c. Absorptive c. Paneth c Stem c. Endocrine c

Small intestinal gland *infolding the epithelium to the lamina propria at the base of villus *types of cells: Goblet c. Absorptive c. Paneth c Stem c. Endocrine c