Absorption and transport Flashcards
Initial development of cell-cell contacts via E-cadheren bond rather than paracellular transport
Tight Junction
Adherens Junction
Adherens Junction
Direct relationship between the number of proteins strands and the permeability of the epithelial cells
Tight Junction
Adherens Junction
Tight Junction
Have high levels of E-cadherens
Tight Junction
Adherens Junction
Adherens Junction
dictates the size of pores and ionic permeability of paracellular pores
Claudins
Occludens
Junctional Adherent Molecules (JAMS)
Claudins
No paracellular transport function
Claudins
Occludens
Junctional Adherent Molecules (JAMS)
Occludens
single membrane spanning polypeptide, regulates the sealing and permeability of TJ
Claudins
Occludens
Junctional Adherent Molecules (JAMS)
Junctional Adherent Molecules (JAMS)
TJ overall effect
increase permeability of TJ ->
inc fluid loss
dec fluid loss
inc fluid loss
opens and closes TJ
zono occludens
involves a transporter and ATP hydrolysis
primary transport
secondary transport
primary transport
benifits electrochemical gradient bought by ATP hydrolysis
primary transport
secondary transport
secondary transport
TJ secretes__ to increase barrier function
Na
Cl
K
HCO3
Cl
Intestinal fluid movement is predominatly controlled by active trasnport of
Na
Cl
K
HCO3
Na
Cl
K
HCO3
Different expression of specific transporters at apical and basolateral poles of enterocytes (Apical Pole or Basolaterla POle)
Na-K ATPase
Na Channel
Cl channels
SGLT1
Na-K ATPase - Baso
Na Channel - Apical
Cl channels - baso
SGLT1 - apical
Basolateral, Apical, Bilateral?
- receptors for luminal regulatory factors
- receptors for kinins
- presence of lymphatics and blood circulation for easy coupling
- receptors for adenosine
- apical
- bilateral
- baso;lateral
- bilateral
They are recruited for development of functional polarity
catenins
Spatial location : Transport porteins
Villus surface: ____
Na channels Na nutrient Na pumps SGLT1 NHE1 NHE2 NHE3 CFTR DRA PAT 1
Na channels Na nutrient SGLT1 NHE2 NHE3 PAT 1
Spatial location : Transport porteins
crypts : ___
Na channels Na nutrient Na pumps SGLT1 NHE1 NHE2 NHE3 CFTR DRA PAT 1
CFTR
Spatial location : Transport porteins
Regular distribution: _
Na channels Na nutrient Na pumps SGLT1 NHE1 NHE2 NHE3 CFTR DRA PAT 1
DRA
Na pumps
NHE1
Enterocytes, goblet cells, paneth cells, enteroendocrine, stem cells
a. ) sense changes in luminal environment and adjust correspondingly
b) most common type with absorptive and secretory function
c) mucus secretion
d. )found in the crypts and can develop in to the other four types
e) defense by secretion of anti-bacterial peptides
a. enteroendocrine
b. Enterocytes
c. goblet cells
d. stem cells
e. paneth cells
(inc/dec????) Na+/nutrient-coupled transport opening of TJ - ↑ fluid absorption via TJ
↑ Cl- secretion - (inc /dec????) barrier function
inc
inc
Type of electrogenic transport or eletroneutral transport
- Na/H exchanger
- Na/glucoes transporter
- Na/K/2Cl cotranspoter
eletroneutral
electrogenic
eletroneutral
Transcellular transport, pump usually use ___ bexause pumps needs to be phophorlated during transport
ATP
ATPase pumps heterodimers (alpha and beta subunits) inhibited by ___
Quabain
ATPase pumps heterodimers (alpha and beta subunits?)
- correct assembly and membrane targeting
- contains the ion binding, catalytic and inhibitor sites
beat
alpha
water selective channelsfor absorption of water
aquaporins
basolateral proteins in small intestines and colon
AQP3
AQP4
AQP8
AQP4
surface / villi of jejunums and colon
AQP3
AQP4
AQP8
AQP8
surface / villi of jejunum, ileum and colon
AQP3
AQP4
AQP8
AQP3
aquaporins found in surface / villi of jejunums
AQP3
AQP4
AQP8
AQP3
AQP8
aquaporin in colon
AQP3
AQP4
AQP8
AQP3
AQP4
AQP8
