Nokea
Which organ is responsible for synthesizing ANP?
- A. the heart
- B. the kidney
- C. the skin
- D. the spleen
Correct Answer: A
Rationale: The correct answer is A: the heart. Atrial Natriuretic Peptide (ANP) is synthesized and released by the atrial cells of the heart in response to stretching of the atrial wall due to increased blood volume or pressure. ANP functions to regulate blood pressure and fluid balance by promoting natriuresis and vasodilation. The kidney (choice B) is responsible for filtering blood and regulating electrolyte balance, but it does not synthesize ANP. The skin (choice C) is involved in thermoregulation and vitamin D synthesis, not ANP production. The spleen (choice D) plays a role in immune function and blood storage, but it does not synthesize ANP.
You may also like to solve these questions
Complete the following sentence: Calcium homeostasis is controlled by…
- A. Insulin
- B. Erythropoietin
- C. Aldosterone
- D. Parathyroid hormone
Correct Answer: D
Rationale: The correct answer is D: Parathyroid hormone. Parathyroid hormone plays a crucial role in regulating calcium homeostasis by increasing calcium levels in the blood through various mechanisms. It promotes calcium release from bones, enhances calcium absorption in the intestines, and reduces calcium excretion from the kidneys. Insulin (Choice A) primarily regulates blood sugar levels, not calcium. Erythropoietin (Choice B) stimulates red blood cell production and does not directly affect calcium homeostasis. Aldosterone (Choice C) regulates sodium and potassium balance but not calcium levels. Thus, Parathyroid hormone is the correct choice for controlling calcium homeostasis.
Which of the pairs of hormones BOTH increase blood sugar?
- A. insulin and glucagon
- B. growth hormone and insulin
- C. glucagon and epinephrine
- D. antidiuretic hormone and glucagon
Correct Answer: C
Rationale: The correct answer is C, glucagon and epinephrine. Glucagon stimulates the liver to release glucose into the bloodstream, increasing blood sugar levels. Epinephrine, also known as adrenaline, has a similar effect by promoting the breakdown of glycogen into glucose. Insulin (choice A) decreases blood sugar by promoting glucose uptake into cells. Growth hormone (choice B) mainly affects growth and metabolism but doesn't directly increase blood sugar. Antidiuretic hormone (choice D) regulates water balance and has no direct effect on blood sugar levels.
Which of the following has both endocrine and exocrine functions?
- A. anterior pituitary
- B. thyroid
- C. adrenal medulla
- D. pancreas
Correct Answer: D
Rationale: The correct answer is D: pancreas. The pancreas has both endocrine (produces hormones like insulin and glucagon) and exocrine (produces digestive enzymes) functions. This dual role makes it unique among the other options. The anterior pituitary (A) is purely endocrine, producing hormones like growth hormone. The thyroid (B) primarily functions as an endocrine gland, producing hormones like thyroxine. The adrenal medulla (C) is also solely endocrine, secreting hormones like epinephrine and norepinephrine. Therefore, the pancreas is the only organ among the choices that performs both endocrine and exocrine functions.
Which of the following elements is required for the synthesis of thyroid hormone?
- A. copper
- B. iodine
- C. sulfur
- D. zinc
Correct Answer: B
Rationale: The correct answer is B: iodine. Iodine is an essential element required for the synthesis of thyroid hormone. Thyroid hormones such as thyroxine (T4) and triiodothyronine (T3) contain iodine atoms. Without sufficient iodine, the thyroid gland cannot produce these hormones, leading to thyroid disorders like hypothyroidism or goiter. Copper (A), sulfur (C), and zinc (D) are not directly involved in the synthesis of thyroid hormone. Copper is important for enzyme function, sulfur is present in amino acids, and zinc is involved in various cellular processes but not specifically in thyroid hormone synthesis.
Hypersecretion of cortisol leads to:
- A. Addison’s disease
- B. Cushing’s syndrome
- C. Acromegaly
- D. Dwarfism
Correct Answer: B
Rationale: Step-by-step rationale for why choice B is correct:
1. Hypersecretion of cortisol is a hallmark of Cushing's syndrome.
2. Excessive cortisol levels can lead to symptoms like weight gain, high blood pressure, and muscle weakness.
3. Cushing's syndrome is characterized by an overactive adrenal gland producing too much cortisol.
4. Addison's disease (choice A) is caused by adrenal insufficiency, leading to low cortisol levels.
5. Acromegaly (choice C) is a growth hormone disorder, not related to cortisol.
6. Dwarfism (choice D) is typically due to growth hormone deficiency, not cortisol excess.
Summary:
Choice B is correct because hypersecretion of cortisol is specifically associated with Cushing's syndrome, causing a range of symptoms related to excess cortisol production. Choices A, C, and D are incorrect as they are not directly related to cortisol hypersecretion.