Who should be on Gluten-Free Diet Anyway?

Digestive System Case Study: Who Should Be on a Gluten-free Diet Anyway?

The abnormal immune response to gluten characterized by celiac disease affects the mucosa, or lining of the small intestinal tract. Which of the following statements about the four histological layers of the alimentary canal is false?

The submucosa consists of a thin layer of connective tissue that protects and accommodates blood vessels, lymphatic vessels, and the submucosal plexus along the respiratory, gastrointestinal, and digestive tracts. The lining of the body's vital organs are essential to prevent lack of nutritional absorption, and provide protection against harmful toxins. The submucosa is positioned deep to the mucosa, and its blood supply goes as far as providing nutrition for the wall of the stomach as well.

In those with celiac disease, the immune response to dietary wheat gluten causes inflammation that affects the mucosal lining of the small intestine.

The mucosa that allow for tissue repair play a very important role within the human body. The lumen of the alimentary tract (also known as the digestive tract) can create harsh environments due to the various substances it comes into contact with such as chyme from digested foods. The lumen happens to be surrounded by a mucosal layer, which contains epithelial tissue. This tissue is quite phenomenal as it is able to quickly repair and replace damaged or dead cells. So, if the lumen of the alimentary tract just so happens to come in contact with a substance that may damage it's tissues, it has the mucosal layer and all of its mucous secretions to protect and repair it if necessary.

Digestion is a process which surprisingly begins with the mouth. We take the first bite of our meal and from there our teeth chew the meal and create a bolus that mixes with our salivary secretions. From there, it flows down the larynx, through the esophagus and into the stomach. Once the contents are in the stomach they are further broken down by digestive enzymes, usually into a liquid form which then goes into the small intestine through the pyloric sphincter. The small intestine proceeds with many further processes to continues with the excreting of the food through defecation in the final process. These processes are important for normal absorption to occur within the body. If any of these processes are not able to function properly, the body will not receive it's vital nutrition for a healthy lifestyle. This can leave a person feeling sick, exhausted, weak, and helpless.

Malabsorption of iron caused by celiac disease can cause a mineral deficiency, which is associated with a condition called atrophic glossitis. The tongue develops a smooth appearance as the filiform papillae atrophy or degenerate. Which statement about filiform papillae correctly describes both their structure and function?

Filiform papillae are found mostly on the tips and sides of the tongue. They are what bestow the rugged appearance of the tongue. Filiform papillae consist of stratified squamous keratinized epithelium and help with mechanical digestion. Mechanical digestion is the term that describes the chewing and breaking of food into tiny pieces to form a bolus.

Dysphagia is defined as difficulty with swallowing. Although rare, severe iron deficiency is associated with dysphagia due to a condition called an esophageal web. These webs are formed by a thin mucosal membrane that occludes or blocks the lumen of the esophagus leading to swallowing difficulty.

There are quite a few phases for the normal swallowing process. Quite obviously it begins with the oral preparation phase. This is when our bodies use mechanical digestion to chew the food into tiny pieces, and create a bolus. From there the bolus goes into the oral transit phase in which the food goes to the back of the tongue and begins the swallowing process. From there the bolus goes into the pharyngeal phase and the soft palate elevates and closes off the nasopharynx stopping food from entering the nasal cavity. From there, it is finally the esophageal phase where food is transferred into the esophagus and transported to the stomach where it prepares for its final stages.

If a person is experiencing dysphagia, it can be very dangerous. Dysphagia can actually cause the muscles from the throat to lose the ability to function properly. If this occurs, the epiglottis may not be working efficiently, and food can enter the trachea causing aspiration which is when food enters the respiratory airways.

If G cells have been damaged by chronic gastritis how will this affect the gastric phase of digestion in          the stomach?

If G cells were damaged by chronic gastritis this would cause gastrin levels to decrease, which would in turn reduce the amount of acid that's secreted by parietal cells. If there were to be a reduction of acid in the stomach, this would cause improper digestion of food, and could possibly lead to malabsorption of nutrition due to the lack of breakdown of the foods by the gastrin secreted by the G cells. This can cause many health issues such as anemia, extreme weight loss, and even osteoporosis.

Inflammation and atrophy of the gastric mucosa that is associated with chronic gastritis would be expected to disrupt the function of the cells found within the gastric pits. A) Discuss the normal function of the gastric glands found within the gastric pits. B) Predict how chronic gastritis might negatively affect the function(s) of each of the following cell types: mucous neck cells; parietal cells; and chief cells.

The gastric glands located in the gastric pits have many functions. They are responsible for the secretion of digestive enzymes and hydrochloric acid into the lumen of the stomach. These digestive enzymes and hydrochloric acid assist in the chemical digestion of food, to be sent to the small intestine where the nutritional components are absorbed, and the toxins are excreted through the process of defecation.

Chronic gastritis can affect many of the important cell types found in the digestive system. Mucous neck cells provide the barrier that protects the stomach lining from harmful components that may damage it, chronic gastritis can decrease the effectiveness of these cells and cause damage to the lining of the stomach. Parietal cells secrete hydrochloric acid, and intrinsic factor. If there is a decrease in the release of intrinsic factor, the body may not be able to absorb vitamin B-12 properly, which can eventually lead to pernicious anemia. Chief cells also secrete gastric juices, and without these gastric juices proper digestion and absorption of nutritional factors may be impaired and lead to malabsorption and nutrition.

Pick the small intestine anatomical feature or cell type whose destruction would directly sever the link       between the digestive system and the lymphatic system?

The loss of lacteals can directly sever the link between the digestive and lymphatic systems. The lymphatic system absorbs fats through lacteals, and transports the fats as chyle. Chyle is a fluid containing free fatty acids and lymph, and gives off the appearance of a milk like substance. Without the lacteals the lymphatic system cannot transport the free fatty acids as chyle, which can decrease lymph production and circulation throughout.

Chronic inflammation disrupts the normal function of the small intestine. A) Discuss how the loss of villi associated with celiac disease leads to nutrient malabsorption in terms of surface area. B) Describe the three types of folding that increase the surface area available for nutrient absorption in the small intestine.

The loss of villi can certainly lead to malabsorption. Considering that these elongated projections increase surface area tremendously, there would be a decrease in the absorption of essential nutrition for the human body. The small intestine may not be able to have the essential surface area to properly intake the nutrition necessary, leading to further complications such as malabsorption.

There is three types of folding that occur in the small intestine that increases the surface area available for nutrient absorption. Plicae circulares are the circular folds that line the mucous membrane of the small intestine. The microvilli are the small projections from the cells that also provide more surface area for nutrient production. Lastly, the villi are projections that are also very close together, and provide surface area to absorb substances especially.

Crohn's disease may cause chronic inflammation of segments of the large intestine. Which of the following physiological processes would be MOST likely affected by Crohn's disease?

Fluid and electrolyte absorption is extremely important for the large intestine, as well as most of the small intestine. If the large intestine can not properly absorb fluids and electrolytes, malabsorption may occur. The effect can be constipation, or even diarrhea in some cases. The gastrointestinal tract must absorb nine liters of fluid daily. If this function is compromised due to the inflammation of the large intestine due to crohn's disease, several of the physiological functions of the body may be compromised.

A patient complaining of fever, chills, nausea, vomiting, and dental pain seeks medical care. The patient is prescribed a two-week course of amoxicillin (an antibiotic in the penicillin family). After 5 days, the patient returns to medical care, complaining of severe diarrhea. Assume that amoxicillin has killed a significant number of the patient's normal gut flora; A) Describe the functions of the normal flora in the large intestine. B) Explain how the loss of normal flora poses a risk of intestinal infections.

The normal flora that reside in the large intestine help to produce certain antibacterial functions, and prevent infections due to pathogens entering the body. These functions range from fermenting indigestible carbohydrates, to synthesizing vitamin K and B complex vitamins, and assisting in the excretion of waste.

The loss of normal flora pose a risk for intestinal infections due to the increased sites pathogens can bind to and replicate, and cause further intestinal infection. The flora are considered the good bacteria that fight these pathogens that float into our systems somehow. If they are eliminated, there will be an extreme increase in the probability of infections occurring due to invading pathogens.

Select the statement that describes how the exocrine pancreas and small intestine work together to increase the efficiency of nutrient absorption? 

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