Nokea
Saliva contains the enzyme salivary amylase. Which food type does salivary amylase begin to break down?
- A. Proteins
- B. Starches
- C. Roughage
- D. Fats
Correct Answer: B
Rationale: Salivary amylase breaks down starches into simple sugars like maltose. Starch is a complex carbohydrate found in foods like bread, pasta, and rice. When you chew food, salivary amylase in saliva starts the digestion process by breaking down starch molecules. Proteins are broken down by stomach enzymes, roughage (fiber) is not digested by enzymes in the mouth, and fats are primarily digested in the small intestine by pancreatic lipase. Therefore, choice B, starches, is the correct answer as salivary amylase specifically targets this food type for initial breakdown.
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The normal endocrine controls can be directly overridden by the __________ system.
- A. nervous
- B. circulatory
- C. digestive
- D. reproductive
Correct Answer: A
Rationale: The correct answer is A: nervous system. The nervous system can directly override normal endocrine controls through the release of neurotransmitters that can stimulate or inhibit hormone release from endocrine glands. The nervous system can rapidly respond to immediate changes in the internal or external environment, allowing for quick adjustments in hormone levels.
Summary of why the other choices are incorrect:
B: The circulatory system is not involved in directly overriding endocrine controls.
C: The digestive system primarily regulates the breakdown and absorption of nutrients, not endocrine controls.
D: The reproductive system is responsible for the production of sex hormones and gametes, but it does not directly override normal endocrine controls.
Calcium level in the blood is regulated by the:
- A. Parathyroid and thyroid
- B. Adrenal medulla and pancreas
- C. Testes
- D. Parathyroid and thymus
Correct Answer: A
Rationale: The correct answer is A: Parathyroid and thyroid. The parathyroid glands secrete parathyroid hormone, which increases blood calcium levels by promoting calcium release from bones and increasing calcium absorption in the intestines. The thyroid gland produces calcitonin, which lowers blood calcium levels by inhibiting bone breakdown and increasing calcium excretion by the kidneys. The adrenal medulla and pancreas do not play a direct role in regulating calcium levels. Testes are not involved in calcium regulation. The thymus is responsible for developing T-cells and does not have a role in calcium regulation.
Which of the following is true about calcium homeostasis?
- A. Increased calcitonin levels will cause increased blood calcium levels.
- B. High calcium levels cause bone resorption.
- C. Parathyroid hormone causes an increase in osteoblast activity.
- D. Parathyroid hormone is the single most important regulator of calcium levels in the blood.
Correct Answer: D
Rationale: The correct answer is D: Parathyroid hormone is the single most important regulator of calcium levels in the blood. Parathyroid hormone plays a crucial role in maintaining calcium homeostasis by stimulating bone resorption, increasing calcium reabsorption in the kidneys, and activating vitamin D to enhance calcium absorption in the intestines. It acts to raise blood calcium levels when they are low.
Explanation for other choices:
A: Increased calcitonin levels actually lower blood calcium levels by promoting calcium deposition in bones.
B: High calcium levels do not cause bone resorption; it is actually the opposite as mentioned in choice D.
C: Parathyroid hormone does not increase osteoblast activity; it primarily affects osteoclasts to release calcium from bones.
Which is not Na+ dependent for absorption?
- A. thiamin
- B. riboflavin
- C. niacin
- D. folate
Correct Answer: D
Rationale: The correct answer is D: folate. Folate absorption is not Na+ dependent as it is primarily absorbed in the small intestine through a carrier-mediated process that is independent of sodium. Thiamin, riboflavin, and niacin absorption, on the other hand, are Na+ dependent processes that rely on sodium co-transporters for uptake in the small intestine. Thiamin is absorbed through a sodium-dependent active transport system, riboflavin requires a sodium-dependent carrier protein for absorption, and niacin absorption involves a sodium-dependent transporter in the small intestine. Therefore, folate is the only option that is not Na+ dependent for absorption.
Antoinette has gone to her primary care provider for a routine physical. Some of her laboratory results indicated an endocrine disorder. In hyperparathyroidism which test results are typical?
- A. Decreased WBC and increased alkaline phosphatase.
- B. Increased calcium and decreased phosphate.
- C. Decreased PTH and increased magnesium.
- D. Increased PTH and decreased calcium.
Correct Answer: B
Rationale: In hyperparathyroidism, increased parathyroid hormone (PTH) leads to increased calcium levels and decreased phosphate levels in the blood.