billiary apparatus and small intestines

Biliary apparatus

A network of thin ducts that carries bile from the liver and gallbladder to the duodenum.

Destination of bile leaving liver lobes

The left and right lobes drain bile into the left and right hepatic ducts, respectively.

Common hepatic duct formation

Formed by the merging of the left and right hepatic ducts.

Cystic duct function

Connects to the common hepatic duct and allows bile to travel into and out of the gallbladder.

Bile flow to and from the gallbladder

Travels from the common hepatic duct → cystic duct → gallbladder for storage; stored bile returns through the cystic duct toward the small intestine.

Common bile duct formation

Formed by the joining of the cystic duct and common hepatic duct.

Common bile duct path

Extends inferiorly toward the duodenum, carrying bile toward the small intestine.

Bile pathway through the biliary apparatus

Liver → hepatic ducts → common hepatic duct → cystic duct → gallbladder → cystic duct → common bile duct → duodenum.

Hepatopancreatic ampulla

The site where the common bile duct and main pancreatic duct merge before entering the duodenum.

Major duodenal papilla

The duodenal opening through which bile and pancreatic juice enter.

Main pancreatic duct function

Carries pancreatic juice from the pancreas toward the duodenum.

Accessory pancreatic duct function

Drains a small amount of pancreatic juice into the minor duodenal papilla.

Minor duodenal papilla

The duodenal opening through which a small amount of pancreatic juice enters from the accessory duct.

Hepatopancreatic sphincter

Structure associated with the hepatopancreatic ampulla that regulates the flow of bile and pancreatic juice into the duodenum.

Meeting point of bile and pancreatic juice

The hepatopancreatic ampulla, before entering the duodenum via the major duodenal papilla.

Intestinal villi

Finger-like projections of the intestinal epithelium that increase surface area for nutrient absorption.

Epithelium covering intestinal villi

Simple columnar epithelium with microvilli, specialized for absorbing nutrients.

Microvilli

Tiny cell membrane projections on simple columnar epithelial cells that further increase surface area for nutrient absorption.

Goblet cells

Cells in the small intestine epithelium that produce mucin to form protective mucus.

Intestinal glands

Glandular structures located in the intestinal mucosa between adjacent villi.

Enteroendocrine cells

Intestinal mucosal cells that secrete hormones regulating digestive activities.

Lamina propria (intestinal villus)

The connective tissue core of a villus containing a capillary network, a lacteal, and a lymphatic nodule.

Capillary network (intestinal villus)

Blood vessels within the villus lamina propria responsible for absorbing water-soluble nutrients.

Lacteal

A lymphatic vessel inside an intestinal villus that absorbs dietary fats and lipid-soluble nutrients.

Lymphatic nodule (lamina propria)

An immune system structure located within the connective tissue layer of the intestinal mucosa.

Components of the intestinal mucosa

Epithelium, lamina propria, and muscularis mucosae.

Submucosa (small intestine)

The layer beneath the mucosa that contains lymph vessels, venules, and arterioles.

Plicae circulares

Circular folds of the small intestine wall that increase surface area for absorption.

Small intestine surface area features (largest to smallest)

Circular folds (plicae circulares) → villi → microvilli.