Question

PICK one of them what is contaminated water, contaminated food, hunger malnutrition as the focus to talk about the digestive system include
how structures may change (think organ layers, protein shape, fluid losses, etc)
how the altered structures affect the physiology
how cells and tissues may be affected
new exposure to toxins or carcinogens
what else you find that doesn't fall into the four previous bullet points

Answer 1

Contaminated water :Whether it's food, air, or water, when you contaminate something, you make it impure or hazardous. Contaminate comes from the Latin word contaminat-, meaning “made impure.” You can use the word to indicate that a hazardous substance has been introduced into something else, such as food that is contaminated with mold.

Food contamination refers to the presence of harmful chemicals and microorganisms in food, which can cause consumer illness. The impact of chemical contaminants on consumer health and well-being is often apparent only after many years of processing and prolonged exposure at low levels.

Malnutrition : Digestive system changes

It was recognized many years ago that the wall of the small intestine of malnourished children is very thin. This is probably due to the thinning of the muscular
layers and to depletion of the other wall tissues. Observations in animals show that
the small intestine loses more weight than any other organ during restriction of protein and energy intake .
With the advent of devices enabling peroral biopsies to be obtained, studies of intestinal mucosal histology were started. Stanneld and co-workers investigated
East African infants with kwashiorkor. In the majority of these children, the mucosa was severely altered, either flat or with thick, short villi, reminiscent of the changes observed in celiac disease. Follow-up studies for up to 1 year did not reveal significant improvement of mucosal architecture. They postulated that these findings were a consequence of the long periods during which the patients had been on low-protein
diets. By contrast, histologic changes in the patients studied by Burman were relatively minor and not sufficient to account for the steatorrhea that was frequently found. The controversy about the magnitude of the histologic damage in malnutrition has not been solved, some authors stating that the mucosa is severely altered and others that it is only mildly affected. A probable explanation for this
discrepancy may be the different quality of the diets. Other factors may be the magnitude of the microbiological contamination of the environment and the ease with which microorganisms may gain access to the intestinal lumen in the areas from which the patients originated.We compared the mucosal histology in patients with marasmus and kwashiorkor
and showed that it was more severely altered in the latter, in whom the majority of changes resembled those of celiac disease (Figs. 1 and 2).

This is in agreement with the description by Stanfield. These patients improved considerably after about a
month on a diet containing gluten: They gained weight and grew, and the signs of vitamin deficiencies disappeared rapidly. The jejunal mucosa of marasmic infants looked nearly normal under light microscopy but was thinner and had lower mitotic counts (Figs. 3 and 4).

​​​​​

Marasmic children who had already begun to gain weight at a satisfactory rate had mitotic counts that were intermediate between the controls and those cases in whom weight gain had not yet started.

Fine structural changes in the enterocytes affect three main parts of the cell:

(a)the brush-border area,

(b) the rest of the cytoplasm, and

(c) the junction area where
the epithelium and the lamina propria meet.

Morphologic changes, consisting of
shortening, branching, and sparsity of the microvilli, were present in many but not
all of the mature cells. These alterations may represent the effect of nutrient restriction on the morphogenesis of the brush border in the cells of the crypts of Lieberkiihn , which, because they are undergoing repeated mitosis and differentiation,
are vulnerable to nutrient deprivation. Similar changes have been shown to appear
under the effect of a variety of physical and chemical agents, including inhibitors of
protein synthesis , and in various pathologic conditions . For this reason, they cannot be considered as specific to malnutrition. The most outstanding
finding in the cytoplasm of the mature absorptive cells in human marasmus is the presence of large bodies of up to 1 to 2 |xm in diameter, which are visible under the
light microscope. It is possible to follow their transition from autophagosomes that contain recognizable organelles to somewhat smaller, more compact, dense residual bodies . The appearance of autophagocytosis is associated with starvation in other organs and tissues, as well as with involution and cell injury from various causes . It is remarkable that other organelles in the absorptive cell appear morphologically normal. Thus the Golgi apparatus contains very low density lipoprotein (VLDL) particles, and the mitochondria and the endoplasmic reticulum are normal. Mitochondria became enlarged and packed with cristae during nutritional rehabilitation. Perhaps this is a sign of subclinical nutrient deficiency, which becomes more evident as growth resumes . Beneath the basal lamella there may be deposits of collagen fibers, of dense, finely fibrillar material, and some fat droplets. Comparable changes have been described in other forms of the malabsorption syndrome and in other organs in conditions in which immune reactions occur close to epithelia . According to Martins-Campos et al. , the decreased numbers of plasma cells in the lamina propria of marasmic infants are a morphologic demonstration of a lack of stimulation or response to stimuli. This may be considered as further evidence of the impaired immune function observed in these
patients.

NOTE :

Due to time constraints I am unable to attend all the questions.If you want solution of remaining questions. You can post again.