Nokea
Oxytocin:
- A. is a neurohypophyseal hormone that stimulates the uterine muscle to contract, thereby assisting in labor.
- B. is a gonadotropin.
- C. stimulates the kidney to reabsorb Na+ and water, thereby expanding blood volume.
- D. is a mineralocorticoid.
Correct Answer: A
Rationale: Rationale:
1. Oxytocin is a neurohypophyseal hormone secreted by the posterior pituitary gland.
2. It plays a key role in stimulating uterine contractions during labor and childbirth.
3. This action helps in the progression of labor by promoting the expulsion of the fetus.
4. Oxytocin also stimulates milk ejection during breastfeeding.
5. Choice A is correct as it accurately describes the role of oxytocin in uterine muscle contraction.
Summary:
B: Oxytocin is not a gonadotropin; it does not directly affect gonadal function.
C: Oxytocin does not stimulate the kidney to reabsorb Na+ and water; that is the role of other hormones like aldosterone.
D: Oxytocin is not a mineralocorticoid; it does not regulate electrolyte balance like mineralocorticoids do.
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Hypothyroidism in children:
- A. Cretinism
- B. Myxoedema
- C. Graves disease
- D. Acromegaly
Correct Answer: A
Rationale: The correct answer is A: Cretinism. Cretinism is a condition of severe hypothyroidism during childhood, leading to stunted growth, intellectual disability, and physical deformities. Myxoedema refers to severe hypothyroidism in adults, not children. Graves disease is a form of hyperthyroidism, opposite of hypothyroidism. Acromegaly is a condition caused by excess growth hormone, not related to thyroid dysfunction. Therefore, Cretinism is the correct answer for hypothyroidism in children due to its specific characteristics and presentation.
Excessive eating despite plenty of glucose in the blood is called:
- A. acidosis.
- B. polyuria.
- C. polydipsia.
- D. polyphagia.
Correct Answer: D
Rationale: The correct answer is D: polyphagia. Polyphagia is the medical term for excessive eating despite adequate glucose levels in the blood, commonly seen in conditions like diabetes mellitus. This excessive hunger is due to the body's inability to use glucose effectively, leading to a constant feeling of hunger.
A: Acidosis refers to an excess of acid in the blood, not related to excessive eating.
B: Polyuria is excessive urination, not directly related to excessive eating.
C: Polydipsia is excessive thirst, also not directly related to excessive eating.
In summary, polyphagia is the correct term for excessive eating despite adequate glucose levels, while the other choices are unrelated to this specific symptom.
The bones, kidneys, and intestine are target organs of this calcium-regulator hormone.
- A. T3 and T4
- B. PTH
- C. ACTH
- D. Oxytocin
Correct Answer: B
Rationale: The correct answer is B: PTH. Parathyroid hormone (PTH) regulates calcium levels in the body by acting on bones, kidneys, and intestine. PTH stimulates release of calcium from bones, reabsorption of calcium in kidneys, and absorption of calcium in the intestine. T3 and T4 are thyroid hormones that do not directly regulate calcium levels. ACTH is adrenocorticotropic hormone that stimulates the adrenal glands. Oxytocin is a hormone involved in labor and lactation, not calcium regulation.
The parathyroid glands maintain adequate levels of blood calcium. This is accomplished through ________.
- A. blocking the action of growth hormone
- B. targeting the bone and activating osteoclasts so that calcium will be released
- C. antagonizing the synthesis of calcitonin
- D. slowing the activity of tissues that require calcium for activity
Correct Answer: B
Rationale: The correct answer is B because the parathyroid glands target the bone and activate osteoclasts to release calcium into the bloodstream. This process helps maintain adequate blood calcium levels. By activating osteoclasts, calcium is released from the bone into the blood, ensuring a balance of calcium levels.
A: Blocking the action of growth hormone is unrelated to the function of parathyroid glands in maintaining blood calcium levels.
C: Antagonizing the synthesis of calcitonin is not the primary mechanism through which parathyroid glands regulate blood calcium levels.
D: Slowing the activity of tissues that require calcium for activity would not help maintain adequate blood calcium levels as it does not address the direct release of calcium from bone by activating osteoclasts.
Which glands are responsible for the regulation of calcium levels in the blood?
- 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 produce parathyroid hormone (PTH), which regulates calcium levels in the blood by increasing calcium absorption from the intestines and releasing calcium from bones. The thyroid gland produces calcitonin, which helps lower blood calcium levels by promoting calcium deposition in bones. The other choices (B: Adrenal medulla and pancreas, C: Testes, D: Parathyroid and thymus) are incorrect because they do not play a direct role in regulating calcium levels in the blood.