Small and Large Intestine Flashcards
How long is the small intestine in humans?
4-6 meters
What is the primary site of absorption and the compeltion of digestion?
small intestine
Plicae circulares
valves of kerkring
valve-like fold/rings in the small intestine
Plicae circulares increase
the surface area
Plicae circulares contain
submucosal core
the mucosal surface of the small intestine is made up of
villi
Villi contain
a core of lamina propria
How long are vili?
1mm
What is the area between vili called
crypts of
Lieberkuhn
Intestinal villi lined by
simple
columnar epithelium
Celiac disease
gluten
enteropathy or allergy
to the wheat protein
gluten)
Celiac disease causes
villus
blunting, atrophy and
loss
leads to malabsorption & weight loss
What is the presence of lymphocytes
epithelial cells
Intraepithelial
lymphocytes
What are the three functional zones in the epithelium of the small intestine?
- Villi
- Crypts
3.Neck – where the villi and crypts meet
All Cells of the small instestine epithelium
- Enterocytes
- Mucous cells
- Paneth cells
- Endocrine cells
- Stem cells
Mucosal cells of the small
intestine called
enterocytes
enterocytes cover
surface of the villi
enterocytes are
Tall columnar cells with
round/oval nuclei
enterocytes apical surface
highly
folded, modified into 2-3000
microvilli
microvilli =
striated or brush
border
the surface of microvilli are coated with
protective
glycocalyx containing enzymes
important for digestion
Enterocytes are separated from luminal surface by
desmosomes and tight junction
Enterocytes Lateral walls have
complex interdigitations
Muscous cells of the SI are Interspersed among enterocytes
and are
mucus secreting goblet cells
Mucous cells of the SI are usually found
in upper 2/3 of crypts
Mucous cells synthesize
mucinogen = mucus
stored in membrane-bound
granule
Mucinogen
lubricates & protects
epithelium
Where are mucous cells least frequently found
doudenum
where are mucous cells most frequently found
ileum
Number of mucous cell increases from _______ to ______
doudeum, ileum
Where are paneth cells found
base of the crypts
small intestine
paneth cell contain
large eosinophilic
granules
paneth cells produce
- defensins (antibacterial proteins)
- lysozyme
Where do you find enteroendocrine cell in the small intestine?
scattered throughout but mainly in the lower third of the cryp
enteroendocrine cells are
SI
Pale-staining cytoplasm, broad
base & narrow at lumen
enteroendocrine cells examples
- s cell
- i cell
- a cell
- k cell
S cell secrete
secretin
secretin
stimulate release of
bicarbonate from pancreas
i cells secrete
cholecystekinin or CCK
cholecystekinin
CCK
stimulates pancreatic seecretion & contraction of
gallbladder
A cell secrete
glucagon
glucagon
increases blood sugar