Consequences of fluid loss
Learning issues.
How loss of fluid can result in: Hypovolaemia, haemoconcentration and ionic
imbalance.
The way in which the body responds to hypovolemia
Recall methods of nausea
Diarrhea
This is characterized by both an increase in frequency and weight of the stool.
This can occur for a variety of reasons
1) Lack of absorption (villus cells. Enterocytes loss ability to reabsorb as
Toxins can bind).
2) Increased secretion (HCO3-, enzymes, Na+) due to crypt cell hyperplasia.
Causes of decreased reabsorption
- Osmotic diarrhea.
This is where an individual consumes an osmotically rich solution, which
increases the osmolality of the tubular fluid. This means there is reduced
reabsorption, as water is drawn into the fluid.
Mannitol, sugary or salty drinks.
However, sometimes there can be a defect in the absorption process, that means
that the water potential is due to reduced absorption.
For example, there can be a Dissacharidase deficiency. This is found in lactose
intolerance.
Due to lack of the brush border enzyme- Lactase, lactose cannot be broken down
Glucose and Galactose.
- Deranged Motility
Where the motility of the small intestine increases, meaning there is reduced
time for reabsorption. This means that the volume of the fecal content will
increase.
- Secretory Diarrhea.
This is where there is increased secretion of ions from the crypt cells.
Secretory Diarrhea is a very common result in cholera. The cholera Toxins result
in increased release of Cl- from the crypt cells and hence, uncontrolled water
secretion.
For example, substances such as; Acetylcholine and Substance P and Cholera act
to increase the rate of secretion (via increasing the intracellular levels of Cl-).
Bacterial: Dysentery (shigella). E-Coli
Viral: Rotavirus and Norovirus.
Learning issues.
How loss of fluid can result in: Hypovolaemia, haemoconcentration and ionic
imbalance.
The way in which the body responds to hypovolemia
Recall methods of nausea
Diarrhea
This is characterized by both an increase in frequency and weight of the stool.
This can occur for a variety of reasons
1) Lack of absorption (villus cells. Enterocytes loss ability to reabsorb as
Toxins can bind).
2) Increased secretion (HCO3-, enzymes, Na+) due to crypt cell hyperplasia.
Causes of decreased reabsorption
- Osmotic diarrhea.
This is where an individual consumes an osmotically rich solution, which
increases the osmolality of the tubular fluid. This means there is reduced
reabsorption, as water is drawn into the fluid.
Mannitol, sugary or salty drinks.
However, sometimes there can be a defect in the absorption process, that means
that the water potential is due to reduced absorption.
For example, there can be a Dissacharidase deficiency. This is found in lactose
intolerance.
Due to lack of the brush border enzyme- Lactase, lactose cannot be broken down
Glucose and Galactose.
- Deranged Motility
Where the motility of the small intestine increases, meaning there is reduced
time for reabsorption. This means that the volume of the fecal content will
increase.
- Secretory Diarrhea.
This is where there is increased secretion of ions from the crypt cells.
Secretory Diarrhea is a very common result in cholera. The cholera Toxins result
in increased release of Cl- from the crypt cells and hence, uncontrolled water
secretion.
For example, substances such as; Acetylcholine and Substance P and Cholera act
to increase the rate of secretion (via increasing the intracellular levels of Cl-).
Bacterial: Dysentery (shigella). E-Coli
Viral: Rotavirus and Norovirus.
