Tag: biology

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Multiple choice biology control and coordination in living organisms parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Tetany (irregular muscle contraction) and osteoporosis are caused due to the deficiency of

  1. Cortisone

  2. Estrogen

  3. Insulin

  4. Parathormone
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hypoparathyroidism is decreased function of the parathyroid glands with underproduction of parathyroid hormone. This can lead to low levels of calcium in the blood, often causing cramping and twitching of muscles or tetany (involuntary muscle contraction).

Multiple choice biology control and coordination in living organisms parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Which of the following is correctly matched?

  1. Thyroxine - tetanus

  2. Insulin - diabetes insipidus

  3. Adrenaline - hepatitis

  4. Parathyroid - tetany
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Tetany is an abnormal condition characterized by periodic painful muscular spasms and tremors, caused by faulty calcium metabolism and associated with diminished function of the parathyroid glands.

Multiple choice biology control and coordination in living organisms parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Parathormone influences calcium absorption in the small intestine by regulating the metabolism of

  1. Vitamin C

  2. Vitamin D
  3. Vitamin $B _{6}$

  4. Enterogasterone
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Vitamin D increases blood concentrations of calcium. It is generated through the activity of parathyroid hormone within the kidney. The most important effect of vitamin D is to facilitate absorption of calcium from the small intestine. Along with thyroid hormone, vitamin D also enhances fluxes of calcium out of bone.

Multiple choice biology control and coordination in living organisms parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Parathormone regulates

  1. Blood calcium level

  2. Blood calcium and phosphate level

  3. Body temperature

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Parathyroid hormone (PTH), parathormone or parathyrin, is secreted by the chief cells of the parathyroid glands. It acts to increase the concentration of calcium ($Ca^{2+}$) in the blood. Parathormone also inhibits the reabsorption of phosphate by the kidney tubules, thereby decreasing serum phosphate concentrations. This potentiates the ability of parathormone to increase serum calcium concentrations because fewer insoluble calcium-phosphate complexes are formed when serum phosphate concentrations are low.

Multiple choice biology control and coordination in living organisms parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

The hormones responsible for regulation of calcium and phosphorous metabolism is secreted by

  1. Pancreas

  2. Thyroid

  3. Thymus

  4. Parathyroid
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Parathormone of parathyroid gland reduces the blood phosphate level while increases the blood calcium level. Antagonistic functions of insulin and glucagon hormones of pancreas maintain the homeostasis of blood glucose level. Thyroid hormones regulate the metabolic rate of the body. Thymus hormone serves in the differentiation of lymphocytes present inside the lobules. Thus, the correct answer is D.

Multiple choice biology control and coordination in living organisms parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Parathyroid hormone

  1. Is produced by the thyroid gland

  2. Is released when blood calcium levels fall

  3. Stimulates osteoblasts to lay down new bone

  4. Stimulates calcitonin release
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Parathyroid hormone is secreted by the parathyroid glands and is the most important regulator of calcium levels in the blood and within the bones. Parathyroid hormone is mainly controlled by the negative feedback of calcium levels in the blood to the parathyroid glands. Low calcium levels in the blood stimulate parathyroid hormone secretion, whereas high calcium levels in the blood prevent the release of parathyroid hormone.

Multiple choice biology control and coordination in living organisms parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Parathormone is secreted during 

  1. Increased blood calcium level

  2. Decreased blood calcium level

  3. Increased blood sugar level

  4. Decreased blood sugar level
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Parathyroid hormone is mainly controlled by the negative feedback of calcium levels in the blood to the parathyroid glands. Low calcium levels in the blood stimulate the parathyroid hormone secretion, whereas high calcium levels in the blood prevent the release of parathyroid hormone. 

Multiple choice biology control and coordination in living organisms parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

The pituitary gland by virtue of its tropic hormones controls the secretory activity of other endocrine glands. Which one of the following endocrine glands can function independently of the pituitary gland?

  1. Thyroid

  2. Gonads

  3. Adrenal

  4. Parathyroid
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The parathyroid glands are four tiny glands, located in the neck, each gland is about the size of a grain of rice. Parathyroid gland secretes parathormone hormone, which regulates $Ca^{++}$ and phosphate ion in the body. This gland works independently to the pituitary gland. 

The pituitary gland, on the other hand, is the major endocrine gland, a pea-sized body attached to the base of the brain that is important in controlling growth and development and the functioning of the other endocrine glands, which includes thyroid, gonads and adrenals etc. 
Therefore, the correct answer is option D.

Multiple choice biology plants and animal hormones parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

The blood calcium level falls too low because

  1. The thyroid gland releases calcitonin, which binds to bone cells

  2. The parathyroid glands release PTH, which binds to kidney cells

  3. The thyroid gland releases thyroid hormone, which binds to small intestine cells

  4. The pancreas releases glucagon, which binds to liver cells

  5. The pituitary gland releases growth hormone, which binds to bone cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Parathormone of parathyroid gland increases the blood calcium level by binding to receptors present on DCT of the nephron to stimulate conditional reabsorption of calcium. Thyroid hormone does not have any specific target cell and stimulate metabolic rate by all cells. Glucagon regulates blood glucose level while growth hormone stimulate overall growth and development. Calcitonin hormone stimulates a temporary reduction in number and activity of osteoclasts (bone cells) and thereby reducing the blood calcium level. Thus, the correct answer is option A.