Phys- Absorption Of Water And Electrolytes Flashcards
The tight junctions in intestinal epithelial cells are most leaky where?
Duodenum- get progressively tighter as you move down the tract
What is the passage of ions and water through the tight junctions and lateral intracellular spaces called?
Paracellular transport
What is transport through the cells called?
Transcellular transport
What contributes more to ion conductance of the mucosa?
A. Paracellular transport
B. Transcellular transport
A. Paracellular transport
Little net H2O absorption occurs in the _____ but chyme is brought to _____ here.
Duodenum, isotonicity
Where does the most H2O absorption occur?
Jejunum
Where is sodium absorbed?
Along the ENTIRE length of the intestine
Where is the net rate of absorption of sodium the highest?
In the Jejunum
- enhanced by presence of sugars and AAs
- Na movement is providing the energy for sugar and AA transport
The colon normally pumps sodium ____ a large electrochemical gradient. What is this affected by?
Against
Affected by aldosterone
Chloride and bicarbonate are absorbed in large amounts where?
Jejunum
Most of the bicarbonate from pancreatic and liver secretions has been reabsorbed by the end of the _____.
Jejunum
In the ____ and ____, Cl continues to be _____ but HCO3- is normally _____. This si dude to a brush border exchange protein not found int he jejunum.
Ileum
Colon
Reabsorbed
Secreted
Net flux of potassium is from ____ to the ____ in the jejunum and ileum.
From lumen to blood
What may be absorbed or secreted in the colon depending on the luminal concentration?
Potassium (above or below 25 mM)
Calcium is ____ absorbed by all segments of the intestine, especially the ___ and _____.
Actively
Duodenum
Jejunum
