- Author:
- Shelley Fong <sfon036@UoA.auckland.ac.nz>
- Date:
- 2024-10-16 10:50:21+13:00
- Desc:
- text fixes
- Permanent Source URI:
- https://models.physiomeproject.org/workspace/be9/rawfile/a728649ce6b054ae9f3a1bc974ab71f68347232a/exposure.rst
Intestines
========================
Food and liquid that has been ingested through the mouth passes through the small and large intestine organs of the gastrointestinal tract, which extract the solids that has been broken up by the stomach. Water absorption is primarily facilitated by the large intestine. What is secreted or not absorbed moves towards the anus.
Pictures
===================
.. figure:: exposure/SI_picture.png
:width: 50%
:align: center
:alt: GI
Fig. 1. The small intestine, surrounded by the large intestine
.. csv-table:: Structural abbreviations
:header: Abbreviation, Name
:widths: 5, 9
C, Colon
DC, Descending Colon
Duod, Duodenum
Jej, Jejunum
PC, Proximal Colon
SI, Small Intestine
Solute transport
===================
The following list contains the known membrane transporters along the small and large intestines.
.. csv-table:: Transporters along the small and large intestines
:header: Abbrev, Channel name, Location, Membrane, Direction
:widths: 5,10,5, 4, 8
AE2, Anion Exchanger 2, throughout, B, Cl\ :sup:`-` in/HCO\ :sub:`3`\ :sup:`-` out
bAE3, Anion Exchanger 3 (brain subtype), ileum/colon, B, Cl\ :sup:`-` in/HCO\ :sub:`3`\ :sup:`-` out
Ca-ATPase, Calcium ATPase, Duod/early Jej, B, Ca out
CaT1, epithelial calcium channel (ECaC), Duod/early Jej, A, Ca in
CFTR, Cyastic Fibrosis Transmembrane Regulator, throughout, A, Cl\ :sup:`-` out
ClC2, Chloride channel (isoform 2), throughout, B, ?
ClC4, Chloride channel (isoform 4), throughout, A, Cl\ :sup:`-` out
DRA, downregulated in adenoma, Duod/ileum/C, A, Cl\ :sup:`-` in/HCO\ :sub:`3`\ :sup:`-` out
ENaC, Epithelial sodium channel, DC, A, Na\ :sup:`+` in
GLUT2, Glucose transporter (isoform 2), SI, B, glu fru out
GLUT5, Glucose transporter (isoform 5), SI, A, fru in
H-K-ATPase, Hydrogen/potassium ATPase, DC, A, K\ :sup:`+` in/H\ :sup:`+` out
K, Unknown potassium channel(s), throughout, B, K\ :sup:`+` out
`NBC <https://models.physiomeproject.org/workspace/87f>`_, Sodium bicarbonate cotransporter, Duod/PC, B, NaHCO\ :sub:`3`\ :sup:`-` out
NHE (Cl\ :sup:`-` dep), Sodium hydrogen exchanger (chloride-dependent), DC, A, Na\ :sup:`+` in/H\ :sup:`+` out
`NHE1 <https://models.physiomeproject.org/workspace/880>`_, Sodium hydrogen exchanger (isoform 1), throughout, B, Na\ :sup:`+` in/H\ :sup:`+` out
`NHE2 <https://models.physiomeproject.org/workspace/880>`_, Sodium hydrogen exchanger (isoform 2), SI/DC, A, Na\ :sup:`+` in/H\ :sup:`+` out
`NHE3 <https://models.physiomeproject.org/workspace/880>`_, Sodium hydrogen exchanger (isoform 3), SI/DC, A, Na\ :sup:`+` in/H\ :sup:`+` out
`NKA <https://models.physiomeproject.org/e/bd7>`_, Sodium/potassium ATPase, throughout, B, 3 Na\ :sup:`+` out/2 K\ :sup:`+` in
NKCC1, Sodium/potassium/chloride cotransporter (isoform 1), throughout, B, Na\ :sup:`+` out/K\ :sup:`+` out/Cl\ :sup:`-` out
NaPi-IIb, Sodium-dependent phosphate cotransporter (Npt2b), SI, A, 3 Na\ :sup:`+`/PO\ :sub:`4`\ :sup:`3-` in
PAT1, Putative anion transporter (isoform 1), Duod/ileum/C, A, Cl\ :sup:`-` in/HCO\ :sub:`3`\ :sup:`-` out
SGLT1, Sodium-glucose cotransporter (isoform 1), SI, A, 2 Na\ :sup:`+` in/glu in
?, , ileum/colon, A/P, Mg\ :sup:`2+` in
?, , throughout, P, PO\ :sub:`4`\ :sup:`3-` in
Solutes: Sodium Na\ :sup:`+`, chloride Cl\ :sup:`-`, potassium K\ :sup:`+`, hydrogen H\ :sup:`+`, bicarbonate HCO\ :sub:`3`\ :sup:`-`, phosphate PO\ :sub:`4`\ :sup:`3-`, magnesium Mg\ :sup:`2+`, glu Glucose, fru Fructose.
Membrane: **A** apical (to lumen), **B** basolateral (to blood), **P** paracellular (to interstitial space).
Direction: movement of solute under normal physiological conditions.
Literature
===================
.. csv-table:: For further reading
:header: Title, Author
:widths: 30, 15
`Physiology of Intestinal Absorption and Secretion <https://doi.org/10.1016%2Fj.bpg.2016.02.007>`_, "Kiela and Ghishan"
`Intestinal ion transport and the pathophysiology of diarrhea <https://doi.org/10.1172%2FJCI18326>`_, "Field"
