Gastroenterology Flashcards
Describe the rectum
Continuous proximally with sigmoid colon and distally with anal canal
Includes transverse rectal folds, anorectal flexure and ampulla
What are the transverse rectal folds?
Three (superior, intermediate and inferior) internal folds of mucous and Submucosa layers
What is the anorectal flexure?
At the levator ani muscles
Important for fecal continence
What is the ampulla of the rectum?
Holds fecal mass until defecation
What is the anorectal junction?
Between the rectum and anal canal
Superior to the anal columns
Includes the pectinate line
What is the pectinate (anorectal) line?
Separates between divergent embryologically derived regions of anal canal
Superior to anal valves
Defines a divergence in arterial supply, venous and lymph drainage and innervation
What is the anal canal?
Between rectum and external anal orifice/anus
Includes the anal columns, valves and sinuses
What are the anal columns?
Longitudinal ridges which contain terminal branches of the superior rectal A and V
What are anal valves?
Pockets in the mucosa that define the anal sinuses
Exist at the inferior end of the anal columns
What are the anal sinuses?
Small recesses which when compressed exude mucus to aid in evacuation of the anal canal
What is the anus?
External opening of the anal canal
