Histology of the Intestines Flashcards
What are the names of the transverse folds with a submucosal fold that cannot lay flat when destended? Hint: They are more visible in the jejunum than in the ileum
Plicae Circularis
The following make-up the core of villi that are found in the small intestines. Which is most critical for fat absorption?
A. Loose CT
B. Microvasculature
C. Lacteal
D. Extensions of lymphatic vessels called
E. C and D
C and D
Lacteal are extensions of lymphatic vessels
T/F: Small intestines are regulated by extrinsics aka preganglionic parasympathetics from (vagus and pelvic splanchnic nn.) and postganlionic sympathetics
True
The simple tubular glands of the intestines are lined with simple columnar epithelium and house what 4 cells?
Enteroendocrine cells
Paneth Cells
M cells (microfold cells)
Intestinal stem cells
Which of the following correctly describes the cell depicted below?
A. Secrete peptide hormones to control gut motility, regulate secretion of enzymes HCl, biles, and other digestive components
B. Participate in innate immunity through secretion of anti-microbe substances like lysozyme or alpha-definsins
C. Houses lymphocytes and macrophages and is found mainnly in ileal mucosa overlying peyer’s patches
D. Daughter cells can move out of the crypts they’re found in and become goblet cells, enterocytes, and enteroendocrine cells
A. Secrete peptide hormones to control gut motility, regulate secretion of enzymes HCl, biles, and other digestive components Enteroendocrine cells
B. Participate in innate immunity through secretion of anti-microbe substances like lysozyme or alpha-definsins
Paneth Cells
C. Houses lymphocytes and macrophages and is found mainnly in ileal mucosa overlying peyer’s patches M cells
D. Daughter cells can move out of the crypts they’re found in and become goblet cells, enterocytes, and enteroendocrine cells Stem Cells
Which of the following cells have apical surface receptors specifc for gram negative bacteria like E. coli?
A. Paneth Cells
B. M cells
C. Enteroendocrine cells
D. Intestinal Stem Cells
M cells
Each of the following helps indicate the transition from Stomach to Duodenum called the Gastroduodenal junction, EXCEPT for what?
A. Change of mucosa layer from simple columnar
B. Decrease in muscular wall thickness
C. Appearance of submucosal glands (Brunner’s glands)
D. Appearance of villi
A. Change of mucosa layer from simple columnar
The epithelium does not really change between stomach and duodenum
Name the Glands depicted in the micrograph below, and then indicate their primary role of their secretions
Brunner’s Glands
Tubular acinar glands that produce alkaline secretion to protect against acidic gastric juices
What two hitological features might help you identify the jejunum?
A. short villi and abundance of submucosal glands
B. long fingerlike villi and abundance of submucosal glands
C. long fingerlike villi and no submucosal glands
D. short villi and no submucosal glands
C. long fingerlike villi and no submucosal glands
- also have well developed lacteal and can find lymphoid follicles in LP
- overall though it’s not a very unique part of the intestine in comparison to duodenum and ileum
Where are we in the GI tract based on the micrograph below?
What is the name of the special feature that tipped you off?
Ileum
Peyer’s Patches
- note, paneth cells can also be found at the base of the patches
Which of the following features do all segments of the small intestine possess?
A. Leaf-like villi
B. Brunner’s glands in the submucosa
C. Peyer’s patches
D. Tubular intestinal glands in the mucosa
Tubular intestinal glands in the mucosa
The ileocecal junction has a thickened extension of what layer?
A. Mucosa muscularis
B. Muscularis Externa
C. Circular Smooth muscle of muscularis externa
D. Longitudinal SM of muscularis externa
Mucosa muscularis
What are the 3 hallmarks of the Large Intestines?
Intestinal Glands
Goblet cells but no intestinal villi
Crypts of Lieberkuhn
Which later of the large intestine forms the Taenieae coli that form the haustra of the Large Intestine?
A. Muscularis mucosae
B. Inner circular layer of muscularis externa
C. Outer longitudinal layer of muscularis externa
D. Lamina porpria and muscularis mucosae
Outer longitudinal layer of muscularis externa
Look at more histology of the Colon
Cool
In the glandular, simple columnar mucosa layer of the colon, what 4 cell types can be found?
Colonocytes
Goblet cells
Stem cells
Enteroendocrine cells
Hirschprung’s Disease is aganglionosis in the distal colon, which of the following is the most common form of Hirschprung’s disease?
A. Short-segment disease meaning it’s confined to rectosigmoid region
B. Long-segment disease meaning it extends past rectosigmoid region to the splenic flexure
C. Total colonic aganglionosis
D. All are equal in incidence
Short-segment disease meaning it’s confined to rectosigmoid region (85%)
Long- 15%
Complete-5%
What is the cause of Hirschprung’s disease?
A. Over transcription of RET gene and resultant overproliferation and migration of NCC into the region
B. Overactivated RET gene and resultant failure of NCC to migrate into the region and differentiate
C. Mut RET gene is unable to signal migration and diffrentiation of NCC into the region
D. Rubella
Mut RET gene is unable to signal migration and diffrentiation of NCC into the region
What are the 3 zones of the anal canal that are found below the rectum proper?
Colorectal Zone
Anal Transitional zone
Squamous Zone
Which of the following correctly describes the colorectal zone of the anal canal? Bonus: Indicate what zones the other options are describing
A. Simple columnar epithelium woth tubular intestinal glands and transverse rectal folds like the rectum proper
B. Simple columnar epithelium transitioning to stratified squamous epithelium
C. Stratified squamous epithelium that continuous with perineal skin
D. None of the above
A. Simple columnar epithelium woth tubular intestinal glands and transverse rectal folds like the rectum proper
- B. Simple columnar epithelium transitioning to stratified squamous epithelium- Anal Transition Zone*
- C. Stratified squamous epithelium that continuous with perineal skin- Squamous Zone*
At all levels of the anus, what layer thickens to form the internal anal sphincter?
A. Muscularis mucosae
B. Outer longitudinal layer of muscularis externa
C. Inner circular layer of muscularis externa
D. Both B and C
