Food And Nutrition 3rd Edition - Chapter 40 Testbank

Hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormone. One of the main symptoms of hypothyroidism is weight gain. This is because the lack of thyroid hormone slows down the body's metabolism, leading to a decrease in calorie burning and an increase in fat storage. Other symptoms of hypothyroidism may include fatigue, dry skin, constipation, and feeling cold. However, weight loss, accelerated heart rate, and diarrhea are not characteristic of hypothyroidism, but rather may be symptoms of hyperthyroidism, which is the opposite condition where the thyroid gland produces too much thyroid hormone.

The pituitary gland works with the thyroid to produce thyroid stimulating hormone. The pituitary gland is located at the base of the brain and is often referred to as the "master gland" because it controls the release of hormones from other glands in the body. In the case of the thyroid, the pituitary gland produces thyroid stimulating hormone (TSH) which signals the thyroid to produce and release thyroid hormones. This feedback loop between the pituitary gland and the thyroid helps to regulate the body's metabolism and energy levels.

Hypothyroidism is usually diagnosed by measuring the blood levels of TSH (thyroid-stimulating hormone), T3 (triiodothyronine), and T4 (thyroxine). TSH is produced by the pituitary gland and stimulates the thyroid gland to produce T3 and T4 hormones. In hypothyroidism, the thyroid gland is underactive and does not produce enough of these hormones. Therefore, measuring the levels of TSH, T3, and T4 in the blood can help determine if a person has hypothyroidism. Other symptoms like the presence of a goitre, weight changes, impaired glucose tolerance, and assessing iodine in the diet may provide additional information but are not specific diagnostic criteria for hypothyroidism.

Adding iodine to all salt used in food processing is the most effective way of improving iodine deficiency in the population. This is because salt is a commonly consumed ingredient and adding iodine to it ensures that everyone gets an adequate intake of iodine. It is a cost-effective and easily implementable solution that can reach a large portion of the population. Encouraging the population to eat more seafood or add iodized salt at the table may not be as effective as not everyone may have access to seafood or may not consistently use iodized salt. Undertaking a mandatory supplementation program or using iodine-based disinfectants in milk production may have limited reach and may not address the issue comprehensively.

The correct answer is "b and c". This means that pregnant women are more likely to avoid seafood and the level of iodine in bread is well below the recommended daily intake (RDI). This suggests that mandatory fortification of bread with iodine may not be successful in pregnant women because they are not getting enough iodine from their diet.

Cassava is the most significant goitrogen associated with goitre because it contains high levels of cyanogenic glycosides, which can interfere with the production of thyroid hormones. When consumed in large quantities, these compounds can inhibit the uptake of iodine by the thyroid gland, leading to goitre development. Other foods on the list, such as Brussels sprouts, garlic, millet, and almonds, also contain goitrogenic compounds but in lower amounts compared to cassava.

Goitre is caused by multiple factors. An iodine deficiency is one of the common causes as iodine is essential for the production of thyroid hormones. However, goitre can also be caused by unknown reasons, indicating that there may be other factors involved that are not yet fully understood. Additionally, disorders that interfere with thyroid hormone production can lead to goitre. Furthermore, the consumption of goitrogens, substances that inhibit thyroid function, can also contribute to the development of goitre. Therefore, all of the mentioned factors can cause goitre.

Hypothyroidism is a condition characterized by an underactive thyroid gland. Selenium is essential for the production of thyroid hormones, and a deficiency in this nutrient can contribute to hypothyroidism. Vitamin A is also important for thyroid function and a deficiency may lead to decreased production of thyroid hormones. Zinc plays a role in the conversion of thyroid hormones and a deficiency can impair this process. Therefore, the correct answer is Selenium, Vitamin A, zinc.

Fortifying bread is an effective method to treat iodine deficiency in Australia. By adding iodine to bread, it becomes a common and easily accessible source of iodine in the diet. This method ensures that a large portion of the population, including those who may not consume milk or drink water regularly, can still receive an adequate amount of iodine. Fortifying bread is a practical and widespread solution that helps address the issue of iodine deficiency in the country.

Cretinism is a condition that affects the growth and development of children, particularly their mental and physical abilities, due to a deficiency in iodine. The question suggests that intakes of iodine less than a certain percentage of the recommended daily intake (RDI) in mothers can lead to cretinism in children. The correct answer, 13%, implies that if mothers consume less than 13% of the RDI of iodine, their children may be at risk of developing cretinism.