Nokea
Which is not a function of the hypothalamus?
- A. Affect heart rate
- B. Control temperature
- C. Affect water balance
- D. Secrete FSH
Correct Answer: D
Rationale: The correct answer is D: Secrete FSH. The hypothalamus produces releasing and inhibiting hormones that regulate the pituitary gland's secretion of hormones such as FSH. The hypothalamus itself does not secrete FSH. A, B, and C are functions of the hypothalamus as it is involved in regulating heart rate, temperature control, and water balance through various hormonal and neural pathways.
You may also like to solve these questions
Epinephrine and norepinephrine from the adrenal medulla will produce the same results as the _____ nervous system.
- A. sympathetic
- B. parasympathetic
- C. somatic
- D. central
Correct Answer: A
Rationale: The correct answer is A: sympathetic. Epinephrine and norepinephrine are neurotransmitters released by the sympathetic nervous system. They activate the fight-or-flight response, increasing heart rate, dilating airways, and redirecting blood flow to muscles. The sympathetic nervous system prepares the body for action in response to stress or danger. Choices B, C, and D are incorrect because parasympathetic regulates rest and digest functions, somatic controls voluntary movements, and central refers to the brain and spinal cord, not a division of the autonomic nervous system like sympathetic.
Which of the following is a function of parathyroid hormone?
- A. It causes the excretion of calcium in the urine.
- B. It stimulates osteoblastic activity to form bone.
- C. It stimulates the thyroid gland to secrete calcitonin.
- D. It increases plasma levels of calcium.
Correct Answer: D
Rationale: The correct answer is D: It increases plasma levels of calcium. Parathyroid hormone (PTH) acts to increase calcium levels in the blood by stimulating the release of calcium from bones, enhancing calcium absorption in the intestines, and reducing calcium excretion in the kidneys. This process helps maintain proper calcium levels in the blood. Choices A, B, and C are incorrect because PTH does not cause the excretion of calcium in the urine (A), stimulate osteoblastic activity to form bone (B), or stimulate the thyroid gland to secrete calcitonin (C).
What ion is sometimes used as a second messenger of amino acid-base hormones?
- A. Iron
- B. Calcium
- C. Sodium
- D. Chlorine
Correct Answer: B
Rationale: The correct answer is B: Calcium. Calcium ions are commonly used as second messengers for amino acid-base hormones due to their ability to trigger various cellular responses. When the hormone binds to its receptor on the cell surface, it activates specific signaling pathways that lead to an increase in intracellular calcium levels. This rise in calcium ions then initiates downstream signaling cascades, ultimately regulating processes such as gene expression, cell growth, and metabolism.
Choice A - Iron: Iron is not typically involved in signaling pathways for amino acid-base hormones. It is more commonly known for its role in oxygen transport and storage in hemoglobin.
Choice C - Sodium: While sodium ions play essential roles in cellular functions, they are not typically utilized as second messengers for amino acid-base hormones. Sodium is more commonly associated with maintaining cell membrane potential and fluid balance.
Choice D - Chlorine: Chlorine ions are not typically involved in signaling pathways for amino acid-base hormones. Chlorine is primarily known for its role in maintaining
What is a potential adverse effect of palpation of an enlarged thyroid gland?
- A. Carotid artery obstruction
- B. Damage to the cricoid cartilage
- C. Release of excessive thyroid hormone into circulation
- D. Hoarseness from pressure on the recurrent laryngeal nerve
Correct Answer: C
Rationale: Palpation of an enlarged thyroid gland may trigger the release of excessive thyroid hormone, especially if the thyroid is overactive, such as in Graves' disease.
With respect to calcium metabolism / bone formation:
- A. osteoclasts secrete alkaline phosphatase
- B. osteoblasts are haemopoietic derivatives of monocyte lineage
- C. 1,25(OH)2 ???D3 and PTH stimulate both osteoblasts and osteoclasts
- D. oestrogens are thought to be protective of osteoporosis as their main effect is osteoblasts stimulation
Correct Answer: C
Rationale: Rationale for Correct Answer (C):
1,25(OH)2 D3 and PTH stimulate both osteoblasts and osteoclasts. 1,25(OH)2 D3 enhances calcium absorption in the gut, promotes bone resorption, and stimulates osteoclast activity. PTH increases calcium levels in the blood by enhancing calcium reabsorption in the kidney and stimulating osteoclast activity. Both hormones indirectly stimulate osteoblasts by increasing calcium availability for bone formation.
Summary of Incorrect Choices:
A: Osteoclasts actually secrete acid, not alkaline phosphatase.
B: Osteoblasts are derived from mesenchymal stem cells, not monocytes.
D: Estrogens have a dual effect, inhibiting bone resorption by osteoclasts and stimulating bone formation by osteoblasts; their main effect is inhibiting osteoclast activity, not solely stimulating osteoblasts.