Intestinal pathology (wk 4) Flashcards
List the components of the small intestine
o Duodenums
o Jejunum
o Ilium
List the components of the large intestine
o Caecum o Ascending colon o Transverse colon o Descending colon o Sigmoid Colon o Rectum
What is the function of the digestive system?
Digestion and absorption
What is the function of bile?
It is an emulsifier
Further absorption
What is the function of pancreatic enzymes?
Further breakdown of food into smaller units
What is classified as diarrhoea?
When faeces is more than 500ml
What are some functions of microorganisms?
Assist digestion
Produce vitamins
Compete for space/nutrition/oxygen
What are the 4 general layers seen in the intestine?
Mucosa
Submucosa
Muscle
Serosa
T/F:
Mature B and T cells are found in Peyer’s Patches
False
They are naive
T/F:
B and T cells in the villi are mature
True
T/F:
Intra epithelial lymphocytes are mostly CD4 T cells
False
Mostly CD8
T/F:
Lamina Properia Lymphocytes are mostly CD4 and B cells
True
Which cranial nerve innervates the gut?
Vagus nerve
What is the function of the muscular layer?
Peristalsis
Makes sure contents move from proximal to distal
What predominantly covers villi?
Mature absorptive enterocytes
T/F:
Villi are long lived
False
• Live only for a few days, die and are shed into the lumen to be digested and absorbed
What are crypts?
moat-like invaginations of the epithelium around the villi, and are lined largely with younger epithelial cells which are involved primarily in secretion
• Toward the base of the crypts are stem cells, which continually divide and provide the source of all the epithelial cells
Which part of the villi is most crucial for absorption?
Tip ;)
What is the function of crypts?
o Secrete ions and water,
o Delivery IgA
o Anti-microbial peptides to the lumen,
o Serve as the site for cell division and renewal
T/F:
Plasma cells in the intestine are mostly IgM positive
False
Mostly IgA positive
Then IgG
T/F:
Small intestine is mostly involved in reclaiming luminal water and electrolytes
False
Large intestine is mostly involved in reclaiming luminal water and electrolytes
Small intestine is more focused on absorption of nutrients
T/F:
There are villi in the colonic mucosa
False
No villi
Flat
T/F:
The intestinal mucosa is the most vulnerable site for pathogenic invasion
True
Describe what happens when an antigen enters the area
Antigen is taken to Peyer’s patch by an antigen presenting cell to activate B and T cells
Drains through lymph nodes and through the blood circulation
Lymphocytes come back to the gut using a homing mechanism (express a molecule that matches the mucosa adhesion molecule ligand in the gut)
Why do children experience rotavirus more than adults?
Their immune system isn’t as developed as adults
Therefore more susceptible
T/F:
Rotavirus is a wheel-like virus and is an opportunistic pathogen
True
T/F:
Rota virus is enveloped and unstable in the environment
False
no envelope
Stable in environment
dsRNA