Nokea
Which hormone is responsible for the reabsorption of sodium in the kidneys?
- A. aldosterone
- B. angiotensin
- C. antidiuretic hormone (ADH)
- D. adrenocorticotropic hormone (ACTH)
Correct Answer: A
Rationale: Aldosterone is the correct answer because it specifically acts on the kidneys to increase the reabsorption of sodium. It is produced by the adrenal glands in response to low blood pressure or low sodium levels. Aldosterone binds to receptors in the kidneys, leading to increased sodium reabsorption and potassium excretion. Angiotensin plays a role in stimulating the release of aldosterone, but it does not directly affect sodium reabsorption. ADH regulates water reabsorption, not sodium. ACTH stimulates the adrenal glands to produce cortisol, not aldosterone. Therefore, aldosterone is the hormone responsible for the reabsorption of sodium in the kidneys.
You may also like to solve these questions
In type 1 diabetes there is an osmotic effect of glucose when insulin deficiency prevents the use of glucose for energy. Which classic symptom is caused by the osmotic effect of glucose?
- A. Fatigue
- B. Polyphagia
- C. Polydipsia
- D. Recurrent infections
Correct Answer: C
Rationale: Polydipsia is caused by the osmotic effect of glucose, leading to excessive urination and increased thirst.
Target cells for hypothalamic releasing hormones are in the
- A. thyroid
- B. hypothalamus
- C. anterior pituitary
- D. posterior pituitary
Correct Answer: C
Rationale: The correct answer is C: anterior pituitary. Hypothalamic releasing hormones target cells in the anterior pituitary to stimulate the release of specific pituitary hormones. The hypothalamus produces releasing hormones that travel through the hypophyseal portal system and bind to receptors on cells in the anterior pituitary, triggering the release of hormones such as ACTH, TSH, LH, FSH, and GH. This interaction between the hypothalamus and anterior pituitary forms the hypothalamic-pituitary axis, regulating various physiological processes. Choices A (thyroid) and D (posterior pituitary) are incorrect as they are not the primary targets of hypothalamic releasing hormones. Choice B (hypothalamus) is also incorrect as releasing hormones do not target cells within the hypothalamus itself, but rather the anterior pituitary.
The antagonistic hormone to calcitonin is _____.
- A. thyroxine.
- B. growth hormone.
- C. insulin.
- D. parathyroid hormone.
Correct Answer: D
Rationale: The correct answer is D: parathyroid hormone. Calcitonin and parathyroid hormone regulate calcium levels in the blood. Calcitonin lowers blood calcium levels by inhibiting bone resorption, while parathyroid hormone increases blood calcium levels by promoting bone resorption. Thus, they have opposite effects on calcium regulation, making parathyroid hormone the antagonistic hormone to calcitonin. Thyroxine (A), growth hormone (B), and insulin (C) do not directly oppose the action of calcitonin in regulating calcium levels.
A 34-year-old carpenter presents to the emergency room after an accident in which he inadvertently chopped off the tip of his index finger. He is taken to the operating room for reattachment of the digit, and after sedation, a local anesthetic is administered around the site of the injury. The local anesthetic used in the procedure did not contain any epinephrine, as it usually does for most surgical procedures. The reason for this is
- A. Epinephrine causes increased blood loss during delicate surgery
- B. Epinephrine causes swelling of the tissues, making surgery more challenging
- C. Epinephrine is contraindicated in emergency surgery
- D. Epinephrine causes vasoconstriction, which can lead to vascular ischemia in digits
Correct Answer: D
Rationale: The correct answer is D. Epinephrine causes vasoconstriction, which can lead to vascular ischemia in digits. In delicate surgeries like finger reattachment, maintaining adequate blood flow is crucial for successful outcomes. Using epinephrine can constrict blood vessels excessively, leading to reduced blood supply and potential tissue damage. This can result in vascular ischemia, compromising the viability of the reattached finger.
Explanation for incorrect choices:
A: Epinephrine actually helps in reducing blood loss by constricting blood vessels.
B: Epinephrine reduces tissue swelling, making surgery easier.
C: Epinephrine is not contraindicated in emergency surgery; it is often used to control bleeding and prolong anesthesia.
The Action of Parathormone in the Human Body
- A. Decreases blood sodium level
- B. Increases blood sodium level
- C. Decreases blood calcium level
- D. Increases blood calcium level
Correct Answer: D
Rationale: The correct answer is D: Increases blood calcium level. Parathormone is released by the parathyroid glands in response to low blood calcium levels. It acts to increase blood calcium levels by stimulating the release of calcium from bones, increasing calcium absorption in the intestines, and promoting calcium reabsorption in the kidneys. This helps to maintain proper calcium levels in the body. Choices A, B, and C are incorrect because parathormone does not have any direct effect on blood sodium levels and actually works to increase, not decrease, blood calcium levels.