Appendix and Colon Flashcards
What is the appendix?
a blind pouch on the right side of the body, extending from the colon
What is the surface epithelium of the appendix? What other cells are found there?
simple columnar
surface absorptive cells, goblets, regenerative cells and DNES cells
Does the appendix have a lamina propria?
yes
Describe the muscularis mucosae of the appendix.
poorly developed
What are other important structures found in the appendix?
short crypts
NO villi
infrequent paneth cells
Describe the submucosa of the appendix.
thick layer with large blood vessels
have numerous lymph nodules
What kind of pattern does the muscularis externa of the appendix have?
normal pattern, but it is very thin
Does the appendix have serosa or adventita?
serosa
what is the function of the appendix?
humoral immunity
resevoir for good bacteria
What is the colon composed of?
cecum, colon, rectum and anus
What is another name for the colon?
large intestine
What else does the colon consist of?
ascending, transverse, descending and sigmoid portions
What is the general function of the colon?
primarily absorption of water
compaction, lubrication and elimination of feces
production of some vitamins
What are some examples of vitamins that are produced in the colon?
riboflavin, thamin, vitamin K and vitamin B12 as bacteria by-products
What cells is the surface epithelium of the mucosa of the colon made of?
simple columnar with many goblets and surface absorptive cells, some regenerative cells and a few DNES cells
What is another name for surface absorptive cells in the mucosa of the colon?
colonocytes
Describe the lamina propria of the mucosa of the colon.
typical and has intestinal glands (crypts)
Describe the muscularis mucosae of the colon.
typical
What does the mucosa of the colon lack?
villi and paneth cells
Describe the submucosa of the colon.
typical
What kind of pattern does the muscularis externa of the colon have?
non-normal pattern
outer longitudinal muscle is gathered into bands called teniae coli and is discontinuous
What is the constant tonus of teniae coli result in?
sacculations called haustra
Which parts of the colon have adventita?
ascending and descending colon
Which parts of the colon have serosa?
transverse and sigmoid colon
What is the general function of the rectum?
store fecal material
What is the surface epithelium of the rectum?
simple columnar
What are some notable features of the rectum?
significant luminal wall folds exist called transverse rectal folds
no teniae coli in muscularis externa (longitudinal is more complete)
luminal wall covering includes adventitia
What is similar to the colon and rectum?
straight intestinal glands with goblet cells
What is the surface epithlium of the anal canal?
transition from simple columnar to stratified squamous
Where do the anal glands extend to?
submucousa
What is the function of the anal gland?
lubricate lumen
Where are the circumanal glands?
skin surrounding anus
What do the mucosa and submucosa of the anus contain?
longitudinal folds to create anal columns
What happens to the muscularis mucosa?
it disappears into the anal canal
What is the internal anal canal?
a thick circular layer of smooth muscle within the muscularis externa
What is the external anal canal?
a striated muscle from the pelvic floor, voluntary muscle
What is the lumina wall covering of the rectum?
adventita
