Ch 1: Nutrient Intake, Digestion, Absorption, & Excretion Flashcards
(37 cards)
Which glycoprotein is secreted by the parietal cells of the stomach?
The Intrinsic Factor (IF)
What is produced in the colon by action of bacteria on fermentable dietary fiber?
Short chain fatty acids (SCFA)
Which substances are absorbed in the stomach?
Aspirin and ETOH
How much volume can a relaxed stomach hold?
A volume of 0.8-1.5 Liters.
In which situations does ASPEN suggest EN be withheld?
- hypoperfusion of the gut splanchnic circulation (often occurs in sepsis/trauma or in pt’s being initiated on catecholamines)
- when catecholamine does are increasing
- when patients require a high level of hemodynamic support including high dose catecholamines (norepinephrine, phenylephrine, or epinephrine, dopamine) to maintain cellular perfusion.
Which are the anorexigenic gut hormones? (appetite suppressing)
Glucagon like peptide 1 & Glucagon like peptide 2 (GLP-1, GLP-2) oxyntomodulin (OXM), Peptide tyrosine tyrosine (PYY), pancreatic polypeptide (PP), & cholecystokinin (CCK)
Which form is most dietary iron in?
Ferric form
Which mineral absorption depend on body stores?
Calcium and Iron
Which patients are at risk for ischemic bowel?
Hyporperfused/hemodynamically unstable; usually have a MAP < 50
Which type of fat does not require formation of micelles or action of bile salts?
MCTs (8-10 carbons long). This type of fat is water soluble, and pass through enterocytes directly into portal circulation.
According to ASPEN guidelines, when should EN initiated for critically ill patients?
Within 24-48 hours when oral intake is not possible
What is the principle metabolic fuel for intestinal cells?
Glutamine; its absence may contribute to mucosal atrophy that accompanies bowel rest
In which form is iron absorbed?
Ferrous form
What part of the brain regulates appetite?
Hypothalamus
What type of fiber should be avoided in critically ill patients?
Insoluble
What is the definition of “trickle feeding”
10-20mL/hour or 10-20 kcals/hours
Trickle feeding can prevent mucosal atrophy in low to moderate risk patents, but will not achieve desired clinical outcomes in high risk patients.
Should C Diff patients be supplemented with probiotics?
Use with caution; evidence for this practice is weak
What is an orexigenic (appetite stimulating) gut hormone?
Ghrelin
During extended periods of fasting (starvation), the main source of energy is from what?
Fatty Acid oxidation
During starvation, glucose utilization is reduced in most tissues and organs because of a reduced supply of glucose and decline in circulating insulin concentration. Higher glucagon concentrations promote fatty acid oxidation. Fat tissue becomes the main energy source for nearly all tissue
Why is Phosphofructokinase (a rate-limiting enzyme of glycolysis) inhibited when ATP is abundant?
Allows the cell to divert glucose to be stored as glycogen
What is the half life of albumin?
20 days
What is the half life of pre-albumin?
2-3 days
Oxidation of fatty acids for adenosine triphosphate (ATP) production occurs where?
In the mitochondria
Where does absorption of large polypeptides, oligopeptides and free amino acids takes place?
Small intestine
