Gastrointestinal Tract Flashcards

Study Notes

Large Intestine (Colon)

Lacks villi and plicae, featuring only crypts.
Structured with the same layers: epithelium, lamina propria, and muscularis.
Teniae coli consist of evenly spaced bands of the outer longitudinal layer of muscularis externa.

Teniae coli Functions

Facilitates contraction of the large intestine.
Enables segments of the colon to contract independently.
Contributes to fecal compaction and general peristalsis.

Haustra coli

Sacculations occurring between teniae coli, allowing parts of the colon to function independently.

Function of the Colon

Principal role includes the recovery of water and salts.
Employs Na+/K+ activated ATPase-driven transport system for fat-soluble substances.
Bacterial activity generates vitamins and results in large amounts of white blood cells.
Displays a thin muscularis mucosae and thick muscularis externa.

Hirschsprung's Disease (Mega-colon)

Congenital disorder characterized by the absence of ganglion cells, leading to chronic constipation due to non-migrated neural crest ganglia.

Appendix

A thin, finger-like blind extension of the colon stemming from the embryonic cecum.
Lacks villi; contains crypts of Lieberkuhn with columnar and goblet cells.
Rich in extensive lymphoid tissue and large lymphatic aggregates.
Features a thick submucosa.

Appendicitis

Occurs due to obstruction of the opening between the cecum and the appendix.

Carcinoid Tumors

Arise from enteroendocrine cells; typically found in the gastrointestinal tract.

Peyer's Patches vs. Lymphatic Nodules

Peyer's patches in the ileum are located anti-mesenteric (on one side), while large lymphatic nodules in the appendix surround the entire structure.

Rectum

Features thick mucosa and simple columnar epithelium.
Contains prominent veins and long crypts primarily composed of goblet cells.

Anus

Composed of stratified squamous epithelium and contains prominent veins.
Similar to the rectum, it has long crypts with a predominance of goblet cells.

Summary of Digestive Functions

Digestive processes include absorption, digestion, and waste elimination, with notable roles played by each component of the gastrointestinal tract.

Description

Explore the essential components of the gastrointestinal tract focusing on the colon, appendix, rectum, and anal canal. These flashcards provide concise definitions and key functions, helping reinforce your understanding of anatomy and physiology in this region.