#1
Which hormone opposes the action of parathyroid hormone (PTH) and lowers blood calcium levels?
Calcitonin
ExplanationCalcitonin inhibits calcium reabsorption in the kidneys, reducing blood calcium levels.
#2
What is the main source of vitamin D for the human body, which is essential for calcium absorption?
Sunlight
ExplanationSunlight is a primary source of vitamin D, crucial for calcium absorption in the body.
#3
Which mineral is often co-regulated with calcium and is important for bone health?
Phosphorus
ExplanationPhosphorus is co-regulated with calcium and plays a crucial role in bone health.
#4
What is the primary function of osteoclasts in bone tissue?
Breakdown of bone tissue
ExplanationOsteoclasts are responsible for breaking down bone tissue, releasing minerals like calcium into the bloodstream.
#5
Which gland produces and secretes calcitonin to help regulate blood calcium levels?
Thyroid gland
ExplanationThe thyroid gland produces and secretes calcitonin to help regulate blood calcium levels.
#6
What is the primary function of the parathyroid hormone (PTH) in the regulation of blood calcium levels?
Increase calcium storage in bones
ExplanationPTH stimulates calcium release from bones to elevate blood calcium levels.
#7
In cases of hypocalcemia, what symptoms might be observed due to low blood calcium levels?
Muscle weakness and spasms
ExplanationLow blood calcium can lead to muscle weakness and spasms as a result of impaired muscle function.
#8
Which of the following hormones plays a role in the regulation of both calcium and phosphate levels in the blood?
Parathyroid hormone (PTH)
ExplanationPTH regulates both calcium and phosphate levels in the blood.
#9
In the context of blood calcium regulation, what is the effect of calcitonin on bone cells?
Stimulation of osteoblast activity
ExplanationCalcitonin stimulates osteoblasts, promoting bone formation and calcium deposition.
#10
Which hormone is responsible for increasing calcium reabsorption in the kidneys, reducing calcium excretion in the urine?
Parathyroid hormone (PTH)
ExplanationPTH increases calcium reabsorption in the kidneys, reducing its excretion in the urine.
#11
Which organ plays a crucial role in the conversion of vitamin D to its active form to regulate calcium absorption?
Kidneys
ExplanationThe kidneys convert vitamin D to its active form, promoting calcium absorption in the intestines.
#12
What is the medical term for the condition characterized by excessive levels of calcium in the blood?
Hypercalcemia
ExplanationHypercalcemia is the condition of elevated calcium levels in the bloodstream.
#13
What is the role of the thyroid gland in blood calcium regulation?
Produces calcitonin to lower blood calcium
ExplanationThe thyroid gland produces calcitonin, which lowers blood calcium levels by inhibiting reabsorption in the kidneys.
#14
In cases of hypercalcemia, what might be a potential symptom associated with the nervous system?
Tingling or numbness
ExplanationNervous system symptoms in hypercalcemia may include tingling or numbness.
#15
What is the name of the condition characterized by a deficiency of parathyroid hormone (PTH) and low blood calcium levels?
Hypoparathyroidism
ExplanationHypoparathyroidism is the condition of low blood calcium due to a deficiency of PTH.