Page 276 - Color_Atlas_of_Physiology_5th_Ed._-_A._Despopoulos_2003

A. Water and electrolyte absorption in the gut
H 2 O Na + Cl – HCO 3 – K + Ca 2+ Fe 2+
Duodenum
Water and Mineral Absorption
Calcitriol
Jejunum

Ileum
Aldosterone Aldosterone
Colon

+
B. Na and H 2 O absorption in the gut (model)
Intestinal + H 2 O
lumen H 2 O Na Plate 10.19
Na +
See D.

Na + Na +
Mucosa
cells ATP
ATP
H 2 O
+
+
Na -K -ATPase
Blood
Na + H 2 O
+
+
1. Na accumulates 2. H 2 O follows, 3. H 2 O and Na flow to base
between cells and the pressure rises of cell and blood
–
+
+
+
C. Na and K exchange D. Na and Cl absorption in gut
in ileum
Na + Cl – Na + Cl – Na + Lumen
In H 2 O+CO 2
+
+
[Na ] [K ] lumen
150 35 Na + 1 2 3 4 5
Concentration (mmol/L) Glucose, Mucosa cell
140 25 H + HCO 3 –
130 15 K + etc. ATP ATP
120 5
20 40 60
Contact time (min) K + Blood 263
Despopoulos, Color Atlas of Physiology © 2003 Thieme
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