Question 1

Patients older than age 70 are encouraged to choose fortified sources of vitamin B₁₂ because the synthetic form is better absorbed than naturally occurring vitamin B₁₂ in foods.

Accepted Answer

This is an example of a synthetic form of a nutrient that is better absorbed than that from food. However, this recommendation applies to patients older than 50 years. The remainder of both the statement and reason are accurate.

Question 2

Which of the following meats is an exceptionally good source of thiamin?

Accepted Answer

Although thiamin is widely distributed in foods and an intake of a variety of foods can ensure adequate amounts, pork is an exceptionally good source of thiamin (vitamin B₁).

Question 3

Each of the following decreases or destroys thiamin content in food except one. Which one is the exception?

Accepted Answer

A moderate amount of olive oil is considered a healthy additive to foods. The remaining selections all decrease of destroy thiamin within food. Restaurants often add baking soda to cooking water of vegetables to retain color. This practice destroys thiamin as does overcooking and high temperatures. Interestingly, the use of antacids reduces use of thiamin. Raw fish contains an active enzyme, thiaminase, which destroys thiamin.

Question 4

The system most likely to be responsible for excessive salivation in a nervous dental patient is the:

Accepted Answer

Physiologically, the sympathetic autonomic nervous system stimulates the body in times of stress and crisis. In contrast, the parasympathetic autonomic nervous system balances or slows down impulses from sympathetic nerves. Whereas the sympathetic impulses influence salivary composition, the parasympathetic system increases the amount of saliva when stimulated. The Krebs cycle, also known as the citric acid or TCA (tricarboxylic) cycle is responsible for metabolic production of energy from carbohydrates, fats and proteins.

Question 5

Patients taking medications for bradycardia (low heart rate) exhibit increased salivary flow because such medications affect salivary secretion control by cholinergic parasympathetic nerves.

Accepted Answer

Patients taking medication for bradycardia exhibit decreased salivary flow. The anticholinergic effects of such medications disrupt the cholinergic mechanisms of the parasympathetic nerves. Disruption of cholinergic nerves that control salivary secretions results in decreased salivary flow.

Question 6

Beriberi manifests with impairment of the autonomic nervous system. Other symptoms include bradycardia and decreased size of the heart.

Accepted Answer

Beriberi, which means "I cannot," manifests as impairment of the central nervous system. This results in impairment of sensory and motor functions including muscular wasting, tachycardia (increased heart rate) and an enlarged heart. Other manifestations include deep muscle pain in the calves and peripheral paralysis. There are two categories of beriberi. Dry beriberi causes muscular wasting, whereas wet beriberi causes edema.

Question 7

Each of the following accurately describes physiological roles of thiamin except one. Which one is the exception?

Accepted Answer

Although thiamin is required for metabolism of carbohydrates, proteins, and fats, the main effects of thiamin deficiency are disturbances of carbohydrate metabolism. Its role as a coenzyme in the Krebs cycle, also called the citric acid cycle or the tricarboxylic cycle (TCA), is production of energy through metabolism of energy nutrients. The logical extension is that thiamin is essential for metabolism of carbohydrates.

Question 8

During early phases of nutritional deficiency, which epithelial tissue is the most likely to be evident?

Accepted Answer

Manifestations of a nutritional deficiency are usually first evident in the glossal (tongue) epithelium.

Question 9

Which condition is least likely to be caused by a deficiency of riboflavin?

Accepted Answer

Although angular cheilosis/cheilitis is associated with deficiency of riboflavin, patients with bilateral cheilosis require thorough evaluation because other factors such as improperly constructed dentures, fungal (candidiasis) or yeast infection, and aging contribute to cheilosis.

Question 10

Deficiencies in which of the following nutrients is least associated with manifestations of systemic disease in the oral cavity?

Accepted Answer

Although all nutrients, including vitamin A, have links to oral health, oral manifestations of systemic diseases caused by deficiencies of the remaining nutrients are seen with more frequency and intensity. Other such nutrients are vitamin K and iron.

Question 11

The most common vitamin deficiency among the B-complex vitamin is usually due to low intake of:

Accepted Answer

Folate, also called folic acid, encompasses several compounds that have nutritional properties similar to those of folic acid. This nutrient functions as a coenzyme for approximately 20 enzymes and is the most common vitamin deficiency among the B-complex vitamins. It functions in conjunction with vitamins B₁₂ and C and usually occurs with other nutrient deficiencies.

Question 12

Vitamin deficiencies, especially the B-complex vitamins, seldom occur in isolation. Folate, a B-complex vitamin, is the exception because it functions separately from other vitamins.

Accepted Answer

If a deficiency of one vitamin is suspected, symptoms of other vitamin B deficiencies also may be present. Folate deficiencies usually occur with other nutrient deficiencies. Specifically, folate functions in conjunction with vitamins B₁₂ and C in maintaining normal levels of mature red blood cells.

Question 13

Consistent high doses of folate can:

Accepted Answer

Prolonged intake of excessive folic acid can mask vitamin B₁₂ deficiency and cause kidney damage. Although cognitive decline has been reported in elderly individuals taking folic acid supplements, a causal relationship between high intake and dementia has not been supported by research.

Question 14

A deficiency of riboflavin can lead to pellagra. Riboflavin is not known to be toxic, but there is no benefit from high doses.

Accepted Answer

A deficiency of niacin can lead to pellagra. (Note, however, that along with thiamin, riboflavin is necessary for synthesis of niacin.) Niacin deficiency results in degeneration of the skin, gastrointestinal tract, and nervous system, a condition known as pellagra. Symptoms of pellagra have been referred to as the 4 Ds-dermatitis, diarrhea, depression or dementia, and death. It is true that riboflavin is not known to be toxic; however, caution is advised because high doses provide no known benefit.

Question 15

Although milk and milk products are excellent sources of riboflavin, approximately 30% of the dietary intake is furnished by foods in the grain group. Meat, poultry, and fish also provide about one-fourth of the dietary requirement.

Accepted Answer

Enriched products provide more riboflavin than their whole-grain counterparts do. A mixed diet that contains a pint of low-fat milk and 4 to 6 ounces of meat daily ensures adequate riboflavin intake.

Question 16

Fungiform papillae are pale pink because they are covered in with keratinized mucosa and have a rich blood supply.

Accepted Answer

Fungiform papillae are covered with keratinized mucosa and have a rich blood supply. It is this highly vascular nature that imparts the bright red color to fungiform papilla. Note that chronic severe nutrient deficiencies result in loss of fungiform papillae and a smooth red tongue.

Question 17

The loss of which papilla types is most likely to result in a loss of taste buds and changes in taste acuity?

Accepted Answer

Taste buds are located on the foliate and fungiform papillae. Foliate papillae appear as visible grooves located on the lateral borders of the tongue. Fungiform papillae are bright red, mushroom-shaped structures scattered throughout the filiform papillae. Of all papillae, taste buds are located only on the foliate, circumvallate lingual, and foliate.

Question 18

Milk purchased in waxy containers contains less riboflavin because the components of the container have the potential to decompose riboflavin.

Accepted Answer

Lighted display cases have the potential to cause decomposition of riboflavin when milk is marketed in translucent plastic containers.

Question 19

Conditions such as burns and growth spurts lead to additional riboflavin requirements because this nutrient acts as a coenzyme in the syntheses of carbohydrates, proteins, and fats.

Accepted Answer

The reason is incorrect because it requires the student to distinguish between the meaning of synthesis and metabolism. Riboflavin acts as a coenzyme in the metabolism of carbohydrates, proteins, and fats. This process is different from the synthesis of nutrients. Metabolism is the process whereby living organisms and cells convert nutrients into energy, structure and waste. Synthesis involves the formation of nutrients.

Question 20

Each of the following oral structures is lined with keratinized mucosa except one. Which one is the exception?

Accepted Answer

The floor of the mouth is lined with nonkeratinized mucosa. The only oral tissues lined with keratinized mucosa are the gingival tissues surrounding the teeth, the dorsum (upper surface) of the tongue, and the hard palate. The remainder of the oral cavity is lined with nonkeratinized mucosa.

Quiz 11: Vitamins Required for Oral Soft Tissues and Salivary Glands

Patients older than age 70 are encouraged to choose fortified sources of vitamin B12 because the synthetic form is better absorbed than naturally occurring vitamin B12 in foods.