Digestive SystemP3 Gallbladder, Pancreas, and Large Intestine

Flashcards covering the physiology, anatomy, and pathologies of the gallbladder, pancreas, and large intestine based on the lecture transcript.

Gallbladder

A sac-like organ attached to the inferior surface of the liver that stores, concentrates, and releases bile.

Bile Tunics

The three layers of the gallbladder wall: an inner mucosa, a middle muscularis, and an external serosa layer.

Cystic duct

A bidirectional duct that connects the gallbladder to the common bile duct, controlled by a sphincter valve.

Cholelithiasis

A condition known as gallstones, caused by the condensation of cholesterol or calcium and bile salts within the gallbladder or biliary apparatus.

Cholecystokinin (CCK)

A hormone from the small intestines released in response to fatty chyme that stimulates gallbladder contraction and the release of pancreatic juices.

Cholecystectomy

The surgical removal of the gallbladder.

Islets of Langerhans

The endocrine portion of the pancreas (2%) where alpha and beta cells produce insulin and glycogen.

Exocrine Function (Pancreas)

The production of pancreatic juice via acinar cells and duct cells to assist with digestive activities.

Acinar cells

Modified simple cuboidal cells arranged in sac-like acini that produce and release hydrolytic enzymes.

Pancreatic juice

An alkaline fluid containing water, bicarbonate, and enzymes such as pancreatic amylase, pancreatic lipase, inactive proteases, and nucleases.

Secretin

A hormone released from the small intestines in response to increased chyme acidity that stimulates the release of alkaline bicarbonate solutions from the liver and pancreatic ducts.

Large Intestine

A wide tube that absorbs water and electrolytes, compacting watery chyme into feces for elimination.

Cesum

The first part of the large intestines, located as a blind sac in the right lower quadrant of the abdomen.

Veriform appendix

A small, finger-like projection off of the cesum that houses lymphoid tissue and normal microbiota.

Colon Segments

The four segments of the colon: ascending, transverse, descending, and sigmoid.

Right colic flexure

The 90-degree sharp turn the ascending colon makes when approaching the liver; also known as the hepatic flexure.

Rectum

A retroperitoneal muscular tube that expands to store feces, featuring thick transverse folds called rectal valves.

Anal canal

The final few centimeters of the large intestine, featuring anal columns and two sphincters: internal (involuntary) and external (voluntary).

Taenia coli

Thin longitudinal bundles of smooth muscle that act like an elastic waistband to bunch the large intestine into haustra.

Haustra

Small sacs or pouches along the large intestines formed by the contraction of the taenia coli.

Omental appendices

Lobules of fat hanging off the external surface of the haustra, also known as epiploic appendages.

Appendicitis

Inflammation of the appendix, often due to fecal matter obstruction, localized to the lower right quadrant.

Gastrocolic reflex

Mass movements in the large intestine initiated by the distension of the stomach, typically occurring after a meal.

Valsalva maneuver

A technique involved in voluntary defecation that includes the maturation of brain coordination and relaxation of the external anal sphincter.

Diverticulosis

The presence of small bulges in the intestinal lining called diverticula, typically found when the colon narrows due to low fiber diet.

Diverticulitis

Inflammation of the diverticula which can become life-threatening and cause rupture.

Crohn's disease

Inflammation that can develop anywhere in the GI tract from mouth to anus, extending through the entire thickness of the bowel wall.

Ulcerative colitis

Inflammation limited to the innermost lining of the large intestine, appearing in a discontinuous pattern.

Sigmoid volvulus

A condition accounting for $8\%$ of intestinal obstructions where the sigmoid colon twists on itself.

Intussusception

A condition where one part of the bowel slides into another like a telescope, occurring most often in babies aged 5 to 10 months.

Sjogren's syndrome

An autoimmune disorder where immune cells attack and destroy glands producing tears and saliva, often presenting with dry mouth and dry eyes.