NROSCI-BIOSC-MSNBIO 1070/2070. November 17, 2014 Gastrointestinal 3. Clinical GI Problems. Damage to the Enteric Nervous System
Pigment stones are produced when bilirubin precipitates with calcium to form a stone. Typically, bilirubin is conjugated with glucuronic acid to make it soluble. Thus, the presence of beta-glucuronidase de-conjugates the bilirubin and results in its precipitation into stones. Beta-glucuronidase is released from a number of bacteria, and thus infections of the gall bladder can lead to formation of pigment stones.
• Theories about food consumption fall into two general “camps.”
The first group of theories hold that food intake is triggered by a depletion of energy reserves in one or more tissues. Thus, eating occurs in response to a shortage of appropriate nutrients.
The second group of theories suggest that we are primed to eat unless inhibitory signals associated by meals are released.
This hypothesis suggests that feeding is determined by the net balance of activity in the VMH and VLH, the VLH serving as a hunger center and the VMH serving to inhibit activity of the hunger center. Not surprisingly, this simplistic hypothesis has not explained the results of subsequent experiments.