Nokea
Thyroxine:
- A. is mostly bound to albumin in the plasma, since this has the largest capacity
- B. is 2-5 times more potent that triiodothyronine (T3)
- C. stimulates TSH release
- D. ∼33% is deiodinated in the liver to T3
Correct Answer: D
Rationale: The correct answer is D. Thyroxine is deiodinated in the liver to T3, so approximately 33% of thyroxine is converted to the more active form, triiodothyronine. This conversion is important for regulating metabolic processes in the body. Choices A and C are incorrect because thyroxine is primarily bound to thyroxine-binding globulin in the plasma, not albumin, and it does not stimulate TSH release. Choice B is incorrect because T3 is actually more potent than thyroxine, not the other way around.
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When blood glucose levels are low, the ______ will increase the secretion of ______.
- A. adrenal cortex: aldosterone
- B. pancreas; glucagon
- C. pancreas: insulin
- D. posterior pituitary: ADH
Correct Answer: B
Rationale: The correct answer is B: pancreas; glucagon. When blood glucose levels are low, the pancreas secretes glucagon. Glucagon acts to increase blood glucose levels by stimulating the liver to release stored glucose. The adrenal cortex does not directly regulate blood glucose levels through aldosterone secretion. Insulin is secreted by the pancreas in response to high blood glucose levels to lower them, not increase them. The posterior pituitary secretes ADH to regulate water balance, not blood glucose levels.
Which of the following is the response to low plasma levels of calcium?
- A. Secretion of calcitonin
- B. Secretion of the beta cells of the islets of Langerhans
- C. Inhibition of the adenohypophyseal release of ACTH
- D. Secretion of PTH
Correct Answer: D
Rationale: The correct answer is D: Secretion of PTH. Low plasma levels of calcium trigger the parathyroid glands to release parathyroid hormone (PTH) to increase calcium levels. PTH acts on the bones to stimulate calcium release, on the kidneys to increase calcium reabsorption, and on the intestines to enhance absorption.
A: Secretion of calcitonin is incorrect because calcitonin is released in response to high calcium levels to lower them.
B: Secretion of the beta cells of the islets of Langerhans is incorrect as these cells secrete insulin in response to high blood glucose levels.
C: Inhibition of the adenohypophyseal release of ACTH is incorrect as ACTH is related to stress response, not calcium regulation.
Growth hormone:
- A. is secreted by the adenohypophysis.
- B. stimulates growth of the musculoskeletal system.
- C. is also called somatotropic hormone.
- D. all is applicable.
Correct Answer: D
Rationale: Certainly! The correct answer is D because growth hormone is indeed secreted by the adenohypophysis, it stimulates growth of the musculoskeletal system, and it is also known as somatotropic hormone. All the statements in choices A, B, and C are true regarding growth hormone, making option D the correct choice. The other choices are incorrect because they do not encompass all the functions and characteristics of growth hormone as described in the question.
Addison's disease frequently causes skin pigment changes. When teaching the patient about medications used for Addison's disease, it is important that he or she understands:
- A. To take plenty of water (at least 8 ounces or 240 mL) with the medication.
- B. Proper subcutaneous injection technique.
- C. That they continue for life.
- D. That they can be stopped when symptoms abate.
Correct Answer: C
Rationale: Patients with Addison's disease require lifelong hormone replacement therapy to manage the condition as the adrenal glands do not produce enough cortisol.
Hyperglycemia, glucosuria, polyuria, and acidosis are:
- A. most apt to be caused by a deficiency of insulin.
- B. characteristic of diabetes insipidus.
- C. the consequences of a hormone-secreting tumor of the beta cells of the islets of Langerhans.
- D. indicative of a deficiency of ADH.
Correct Answer: A
Rationale: Step-by-step rationale for choice A being correct:
1. Hyperglycemia is high blood sugar due to insufficient insulin to regulate glucose levels.
2. Glucosuria is the presence of glucose in urine, indicating excess blood sugar not being reabsorbed.
3. Polyuria is increased urine production due to osmotic diuresis from excess glucose in the urine.
4. Acidosis results from the breakdown of fats in the absence of sufficient glucose utilization.
5. All these symptoms align with uncontrolled diabetes mellitus, where insulin deficiency leads to these metabolic disturbances.
Summary of why other choices are incorrect:
B: Diabetes insipidus is characterized by excessive thirst and urination due to inadequate ADH, not hyperglycemia.
C: Hormone-secreting tumor of beta cells would lead to hyperinsulinemia and hypoglycemia, not hyperglycemia.
D: ADH deficiency would result in dilute urine and electrolyte imbalances