Gut L1 Flashcards
what is the function of the mucous neck cell?
- secretes mucus
what is the function of the surface mucous cell?
secretes mucus
what is the function of the parietal cell?
secretes HCl and intrinsic factor
what is the function of the chief cell?
secretes pepsinogen
what is the function of the
G cell?
secretes hormone GASTRIN
what is the length of the small intestine
6m
where is the submucosal plexus located?
between circular muscle and sub mucosa
- controls SECRETION by GI tract
- main sensory neuron for SECRETION is CHEMORECEPTORS
where is the myenteric plexus located
the main sensory neuron for motility is what
between the 2 muscle layers
- controls MOTILITY, FREQ and STRENGTH of GI tract contraction
- the main sensory neuron for motility is DISTENSION
what is the role of Brunner’s gland
where is it
bicarbonate sectretion
in the jejunum
what is the effect of coeliacs disease
- low in microvilli O less absorption (20x)
Crohns disease can lead to what
short bowel syndrome if some of the bowel is surgicallly removed O not enough s.a to absorb nutriets
describe the duodenum
the duodenum is how much
the first 12cm of s. i
- has a high vol of food
- high conc of nutrients
- highly vascularised O appears red
- cont Brunner’s glands
- cont plicae (additional folding)
describe the jejunum
- cont Brunners glands
- highly vascularised O dark appearabce
- long villi, large s.a
describe the ileum
- part of s.i that joins to l. int
- paler appearance
- Peyer’s patches (lymphatics)
- short villi O smaller s.a
enterocytes are what type of cell?
absorbative cells
what are tight junctions?
give exaples of the proteins involded
- cells joined together by projections of cell membrane
- occludin and claudin proteins
- decrease permeability
what is the role of hormones in the gut
- control secretions
- control motility
- feedback to hypothalamus for control
endocrine cells of the gut can be what?
open
- clear connection to gut lumen ( eg for pH, glucose presence)
closed
- no connection to gut lumen but still respons to diet to release hormones
whata re the properties of an endocrine cell in the gut
- highly polarised (hormone containing secretory granules towards basal pole of cell
- close to CAPILLARY network of lamina propria
- close to ENTERIC NS, has receptors for NEURAL MODULATION
hormone secretion in the gut is controlled by what?
1) the contact with nutrients which increases blood levels
2) by triggering the enteric NS
where are Peyer’s patches?
- in the LAMINA PROPRIA
- catch microorganisms and other antigens
- uses DENDRITIC CELLS, B-LYMPHOCYTES & T- LYMPHOCYTES
- covered by MICROFOLD cells which lack microvilli
- M cells sample antigen directly from lumen, deliver ti to antigen presenting cells
- gut associated lymphoid tissue
in the colon longitudinal musc is in how many bands? what is it called?
- 3 bands
which is the only oart of GI that cont skeletal muscle?
- colon (external muscle sphincter)
what kind of folding is found in in the colon
- basolateral folding
