DH 209 Nutrition Exam

Correct Answer:

B. Vegan

Explanation of the Correct Answer:

Vegans are most at risk for nutrient deficiencies because they avoid all animal products, including dairy, eggs, and meat. This can lead to potential shortages of essential nutrients such as vitamin B12, iron, calcium, omega-3 fatty acids, vitamin D, and protein. These nutrients are often found in animal-based foods, and a vegan diet requires careful planning to ensure that adequate amounts of these nutrients are obtained through plant-based sources or supplements.

Why the Other Options Are Incorrect:

A. Semi-vegetarian

A semi-vegetarian typically follows a mostly plant-based diet but occasionally consumes small amounts of meat or fish. Since they still consume animal products, they are less likely to experience the nutrient deficiencies that vegans might face.

C. Lacto-ovovegetarian

Lacto-ovovegetarians consume both dairy products and eggs, which help provide essential nutrients like calcium, vitamin B12, and protein. This makes them less at risk for nutrient deficiencies compared to vegans.

D. Pollo-vegetarian

A pollo-vegetarian includes poultry in their diet but avoids red meat. The inclusion of poultry provides a source of important nutrients like protein, iron, and vitamin B12, making them less likely to have nutrient deficiencies compared to vegans.

Summary:

Vegans are most at risk for nutrient deficiencies because their diet excludes all animal products, which are key sources of several essential nutrients. Semi-vegetarians, lacto-ovovegetarians, and pollo-vegetarians are less at risk since they still consume some animal-based products.

Correct Answer:

A. Both statements are true.

Explanation of the Correct Answer:

Enzymes are biological catalysts that accelerate chemical reactions in the body. They are crucial for both degradation (catabolism) and biosynthesis (anabolism) of biomolecules, making them essential for metabolism and the overall functioning of life. The first statement correctly describes the broad role of enzymes in metabolism, as they are involved in breaking down molecules for energy and building new molecules for cellular processes.

Proteases, amylases, and lipases are specific types of enzymes:

Proteases break down proteins into amino acids.

Amylases break down carbohydrates (like starches) into simpler sugars (like maltose).

Lipases break down fats into fatty acids and glycerol.

These enzymes are essential for digestion and other metabolic processes, confirming that the second statement is also true.

Why the Other Options Are Incorrect:

B. Both statements are false.

This option is incorrect because both the statements are actually true. Enzymes do perform chemical reactions involved in metabolism, and proteases, amylases, and lipases are specific examples of enzymes involved in degradation and biosynthesis processes.

C. The first statement is false; the second is true.

This option is incorrect because the first statement is actually true. Enzymes are responsible for catalyzing the chemical reactions involved in both the degradation and biosynthesis of biomolecules. The second statement is true as well, so this option is incorrect.

D. The first statement is true; the second is false.

This option is incorrect because the second statement is also true. Proteases, amylases, and lipases are indeed enzymes that help in the breakdown of proteins, carbohydrates, and fats, respectively, which are essential for digestion and metabolism.

Correct Answer: B. Lack of physical activity of host

Explanation of the Correct Answer:

B is correct because lack of physical activity of the host is not typically considered one of the fundamental factors that result in disease processes. While physical inactivity can contribute to certain diseases (such as cardiovascular diseases or diabetes), it is not a direct, essential factor in the initiation of disease in the same way that the other factors are.

Why the Other Options are Incorrect:

A. Resistance of the host

This is incorrect because the resistance of the host refers to the ability of the body’s immune system to prevent or fight off infections and diseases. It is a key factor in disease processes, as it directly affects whether a person will become ill when exposed to an etiologic agent.

C. Presence of an etiologic agent

This is incorrect because the presence of an etiologic agent (such as bacteria, viruses, or fungi) is a critical factor in disease processes. Diseases are often caused by these agents, and their presence is necessary for the disease to occur.

D. Environmental factors

This is incorrect because environmental factors (such as pollution, climate, and sanitation) are important contributors to disease processes. These factors can create conditions that facilitate the spread of disease or make individuals more susceptible to it.

E. Susceptibility of the host

This is incorrect because the susceptibility of the host is another crucial factor in disease processes. The genetic makeup, age, nutritional status, and overall health of an individual determine their susceptibility to disease, making it a key factor in whether or not disease develops.

Correct Answer:

C. Milk

Explanation of the Correct Answer:

Milk contains the most significant level of carbohydrates among the listed animal-derived foods. The primary carbohydrate in milk is lactose, a disaccharide composed of glucose and galactose. Lactose makes up about 4-5% of the composition of milk, making it a significant source of carbohydrates for those who consume dairy products.

Why the Other Options Are Incorrect:

A. Egg:

Eggs are primarily composed of protein and fat, with very little carbohydrate content. The carbohydrate content in eggs is almost negligible, so they do not contribute a significant amount of carbohydrates to the diet.

B. Poultry:

Like eggs, poultry (such as chicken or turkey) is high in protein and fat, but contains very little carbohydrate. Poultry meat does not provide significant carbohydrate content.

D. Beef:

Beef, like poultry, is primarily composed of protein and fat, and contains minimal amounts of carbohydrates. Beef does not contribute a notable amount of carbohydrates.

Correct Answer:

D. Both statements are true.

Explanation of the Correct Answer:

The first statement is true:

The stomach acts as a reservoir that holds food after it enters. The average meal typically stays in the stomach for about 6 to 8 hours before being passed into the small intestine. This time can vary depending on factors such as meal size, composition, and individual factors (e.g., gastric motility). The stomach's role is to store food, start the digestion process, and gradually release food into the small intestine.

The second statement is true:

The rate at which different types of food pass through the stomach varies. In general, the rate of gastric emptying is as follows:

Liquids: Liquids pass through the stomach the fastest, as they are easily absorbed and do not need as much time for digestion or breakdown.

Carbohydrates: Simple carbohydrates typically follow, as they are relatively easy to break down and digest.

Proteins: Proteins take longer to digest and therefore move through the stomach at a slower rate than carbohydrates.

Fats: Fats take the longest to digest, as they require more time for enzymatic breakdown and absorption, and thus pass through the stomach last.

Why the Other Options Are Incorrect:

A. Both statements are false.

This option is incorrect because both statements are true. The stomach functions as a reservoir, and the passage rates for different food types follow the described order (liquids, carbohydrates, proteins, and fats).

B. The first statement is true; the second is false.

This option is incorrect because the second statement is actually true. The passage rates of liquids, carbohydrates, proteins, and fats are well-documented, and they follow the correct order as described.

C. The first statement is false; the second is true.

This option is incorrect because the first statement about the stomach acting as a reservoir to hold food for 6 to 8 hours is accurate. Therefore, both statements are true.

Correct Answer: D. Use an alcohol-based mouthwash for rinsing after eating

Explanation of the Correct Answer:

D is correct because using an alcohol-based mouthwash is not recommended for patients with xerostomia (dry mouth). Alcohol can further dry out the oral tissues, exacerbating the symptoms of xerostomia. Patients experiencing dry mouth should be advised to use alcohol-free mouth rinses formulated specifically for dry mouth relief, which help to moisturize and protect the oral tissues without causing further dehydration.

Why the Other Options are Incorrect:

A. Use non-nutritive sweeteners

This is incorrect because non-nutritive sweeteners, such as xylitol, can stimulate saliva flow without contributing to tooth decay. Sugar-free gums and candies containing xylitol are often recommended to help manage xerostomia.

B. Carry a water bottle around during the day

This is incorrect because sipping water frequently throughout the day helps to keep the oral mucosa moist, reduces discomfort, and can help in flushing out food debris and bacteria, thus helping to manage xerostomia effectively.

C. Use a humidifier to maintain humidity in the air

This is incorrect because maintaining humidity in the environment, especially during sleep, can help reduce symptoms of dry mouth. A humidifier can keep the mucous membranes more hydrated and improve overall comfort.

E. Use lip balm to help keep lips moist

This is incorrect because xerostomia often causes dry, cracked lips. Applying lip balm helps to protect and soothe the lips, preventing discomfort and secondary infections related to dryness.

Summary:

Using an alcohol-based mouthwash is not an effective intervention for xerostomia and can worsen dry mouth symptoms, making D the correct answer. In contrast, recommending non-nutritive sweeteners, carrying a water bottle, using a humidifier, and applying lip balm are all effective and easy-to-implement strategies to help patients manage xerostomia.

Correct Answer: False

Explanation of the Correct Answer:

The statement is false because fluoride incorporated into developing tooth enamel forms fluorapatite, which is actually more resistant to demineralization than hydroxyapatite (the naturally occurring mineral in enamel). Fluorapatite is more resistant to acids produced by bacteria in the mouth, making it less prone to decay and more resistant to the process of demineralization.

Why the Other Option is Incorrect:

True

This would be incorrect because fluorapatite (formed by fluoride incorporation into enamel) is more resistant to demineralization, not less. Fluoride helps in the remineralization process and strengthens the enamel, reducing the risk of tooth decay.

Correct Answer: A. Calcium within saliva increases the risk for caries.

Explanation of the Correct Answer:

A is correct because calcium within saliva does not increase the risk for caries. In fact, calcium in saliva actually plays a protective role against dental caries. It helps to mineralize demineralized enamel, a process that can help repair the tooth enamel that has been softened by acidic conditions in the mouth. Calcium in saliva can help reduce the risk of caries, not increase it.

Why the Other Options are Incorrect:

B. Calcium in saliva provides a buffering action

This is incorrect because calcium does provide a buffering action in the mouth. It helps to neutralize acids and maintain a balanced pH, which reduces the demineralization of tooth enamel and helps to protect against caries

C. Saliva is a source of calcium to mineralize demineralized enamel.

This is incorrect because saliva does indeed act as a source of calcium to help remineralize demineralized enamel. When enamel starts to break down due to acidic exposure, calcium from saliva can help restore the enamel and repair early stages of decay.

D. Saliva is supersaturated with calcium

This is incorrect because saliva is supersaturated with calcium, meaning it contains more calcium than it can hold in a stable form, which makes it effective in preventing demineralization of teeth and promoting remineralization. This helps to protect teeth from the harmful effects of acids and caries.

Correct Answer:

C. Increased salivary flow

Explanation of the Correct Answer:

Increased salivary flow actually protects the teeth from dental erosion rather than contributing to it. Saliva helps neutralize acids in the mouth, wash away food particles, and provide minerals (such as calcium and phosphate) that aid in remineralizing enamel. Increased salivary flow, such as that produced by chewing or stimulation, can reduce the risk of dental erosion and help maintain oral health.

Why the Other Options Are Incorrect:

A. Frequent consumption of acidic beverages:

Frequent consumption of acidic beverages, such as sodas, fruit juices, and sports drinks, is strongly associated with increased dental erosion. The acids in these beverages can erode tooth enamel, leading to sensitivity, discoloration, and decay over time.

B. Prolonged holding of food in the mouth:

When food or beverages are held in the mouth for an extended period, especially those high in sugar or acid, it allows the acids or sugars to come into prolonged contact with the teeth. This increases the risk of dental erosion by giving the acids more time to break down enamel.

D. Mouth breathing:

Mouth breathing can lead to dry mouth, which reduces the amount of saliva in the mouth. As saliva plays a crucial role in neutralizing acids and protecting teeth, reduced salivary flow due to mouth breathing can increase the risk of dental erosion.