Biology · General Awareness

Human Endocrine System

1,530 Questions

The human endocrine system comprises glands that secrete hormones to regulate bodily functions like metabolism, growth, and reproduction. Competitive exams frequently test the specific roles of hormones such as adrenaline, insulin, and progesterone. Use these questions to master the locations and functions of different hormones.

Hormone functionsIslets of LangerhansFight or flight responseBlood pressure regulationFemale sex hormonesWater soluble hormones

Human Endocrine System Questions

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

Hormone responsible for regulation of calcium and phosphorus homeostasis is secreted by

  1. Pituitary

  2. Parathyroids

  3. Thymus

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

The parathyroid glands are small endocrine glands in the neck that produce parathyroid hormone. Humans have four parathyroid glands, which are usually located behind the thyroid gland and in rare cases, within the thyroid gland or in the chest. Parathyroid glands control the amount of calcium in the blood and within the bones.

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

Which of the following statements is correct for 'parathormone'?

  1. It increases blood calcium level and decreases calcium store of the bone

  2. It decreases blood calcium level and increased calcium store of the bone

  3. It increases blood glucose level and decreases calcium store of the bone

  4. It decreases blood glucose level and increases calcium store of the bone
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Parathormone (PTH) increases blood calcium levels by stimulating bone resorption (releasing calcium from bone) and increasing calcium reabsorption in the kidneys.

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

In which of the following options, hormone is not matching with its source and function?

  1. Hormone- Glucocorticoids, Source-Adrenal cortex, Function-Produces anti-inflammatory reactions

  2. Hormone-Vasopressin, Source-Posterior pituitary, Function-Stimulates resorption of water and electrolytes
  3. Hormone-Parathyroid hormone, Source-thyroid, Function-Decreases the blood $Ca^{2+}$ level

  4. Hormone-Melatonin, Source-Pineal gland, Function-Maintains sleep-wake cycle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hormone released by the parathyroid gland is parathyroid hormone also called parathormone or parathyrin, this hormone regulates the Ca$^{+2}$ concentration in the serum by acting upon bone, kidney and intestine.

So, the correct answer is 'Hormone-Parathyroid hormone, Source-thyroid, Function-Decreases the blood Ca$^{+2}$ level'

Multiple choice biology plants and animal hormones 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

The kidney processes Vitamin D into calcitriol, the active form that is most effective in assisting intestinal absorption. This process is stimulated by parathyroid hormone. Vitamin D is an important co-factor in the intestinal absorption of calcium, as it increases the number of calcium binding proteins, involved in calcium absorption through the apical membrane of enterocytes in the small intestine.

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

Name the two hormones that regulates blood calcium levels in the body

  1. Insulin and glucagon

  2. Thyroxine and estrogen

  3. Thyrocalcitonin and parathyroid hormone

  4. Prolactin and oxytocin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Thyrocalcitonin (TCT) is secreted when calcium level in blood is high. It then lowers the levels by suppressing  release of calcium ions from bones. Whereas parathyroid hormone increases the blood calcium level by increasing calcium absorption from intestine and mobilising calcium from bones to blood.

Multiple choice zoology endocrine system and chemical co-ordination parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Increase in bleeding time and delay in blood coagulation is due to the deficiency of which hormone?

  1. Thyroxine

  2. Adrenaline

  3. Noradrenaline

  4. Parathormone
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • In humans, four parathyroid glands are present on the back side of the thyroid gland, one pair each in the two lobes of the thyroid gland.
  • The parathyroid glands secrete a peptide hormone called parathyroid hormone (PTH) or parathormone.
  • Parathormone increases the $Ca^{2+}$ levels in the blood.
  • Increase in bleeding time and delay in blood coagulation is due to the deficiency of parathormone because its deficiency causes a decrease in blood calcium levels and calcium ion is essential for blood coagulation.
  • So, the correct answer is 'Parathormone'.
Multiple choice zoology endocrine system and chemical co-ordination parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Which of the following reasons states that parathyroid is hormone is a hypercalcemic hormone?

  1. PTH also stimulates reabsorption of Ca2+ by the renal
    tubules

  2. PTH increases Ca2+ absorption from the digested food

  3. PTH control the metabolism of carbohydrates,
    proteins and fats

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In humans, four parathyroid glands are present on the back side of the thyroid gland, one pair each in the two lobes of the thyroid gland. They secrete a peptide hormone called parathyroid hormone (PTH).
PTH increases Ca2+ absorption from the digested food. it also stimulates reabsorption of Ca2+ by the renal tubules.PTH acts on bones and stimulates the process of bone resorption (dissolution/demineralization). 
 Hence PTH is a hypercalcemic hormone, i.e., it increases the blood Ca2+ levels. Along with TCT(Thyrocalcitonin), it plays a significant role in calcium balance in the body

So, the correct option is 'Both A and B'.

Multiple choice zoology endocrine system and chemical co-ordination parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Parathyroid hormone is: 

  1. Protein

  2. Carboh

  3. Lipid

  4. Steroid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • parathyroid hormone (PTH) is a protein in nature composed of 84 amino acids. 
  • parathyroid glands make more or less parathyroid hormone (PTH) in response to the level of calcium in the blood. 
  • When the calcium in our blood goes too low, the parathyroid glands make more PTH. so, option A is correct answer .

    • Multiple choice zoology endocrine system and chemical co-ordination parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

    Which of the following hormones coordinate with each other to maintain ideal blood $Ca$ level?

    1. Thyrocalcitonin and glucagon

    2. Parathyroid hormone and cortisol

    3. Thyrocalcitonin and Thyroxin

    4. Thyrocalcitonin and Parathyroid hormone
    Reveal answer Fill a bubble to check yourself
    D Correct answer
    Explanation
    • In addition, tetraiodothyronine or thyroxine (T4) and triiodothyronine (T3) Thyroid gland also secretes a protein hormone called thyrocalcitonin. 
    • Thyrocalcitonin(TCT) lowers blood calcium levels. It counters the actions of parathyroid hormone which increases the blood calcium level.
    • The parathyroid glands monitor the calcium in the blood 24 hours per day. The four parathyroid glands make more or less parathyroid hormone (PTH) in response to the level of calcium in the blood. When the calcium in our blood goes too low, the parathyroid glands make more PTH in order to increase the blood calcium levels.
    • Hence Thyrocalcitonin and Parathyroid hormones coordinate with each other to maintain ideal blood Ca level.
    • So, the correct answer is 'Thyrocalcitonin and Parathyroid hormone'.
    Multiple choice zoology endocrine system and chemical co-ordination parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

    Hormone regulating calcium and phosphorus metabolism in the body is secreted by 

    1. Thyroid

    2. Parathyroid

    3. Thymus

    4. Pancreas
    Reveal answer Fill a bubble to check yourself
    B Correct answer
    Explanation
    A. Thyroid gland is situated between the trachea and larynx in the neck and secretes thyroxine hormone which increases oxygen consumption by metabolically active tissues.
    B. Parathyroid gland is present in the form of four small pouches which are embedded in the posterior surface of lobes of thyroid gland. This gland secretes parathormone which increases calcium reabsorption from the bones and causes mobilisation of calcium in the blood. This hormone also regulates phosphate excretion through urine.
    C. Thymus gland is associated with the development of immune system and present on the dorsal side of heart. It secretes thymosin hormone which plays an important role in the differentiation of T-lymphocytes.
    D. Pancreas is a heterocrine gland as it acts both as endocrine and exocrine gland. It secretes insulin hormone into blood and act as endocrine gland and when it secretes digestive enzymes and juice through pancreatic duct, it acts as exocrine gland.
    Hence, hormone regulating calcium and phosphorus metabolism in the body.
    So, the correct answer is 'Parathyroid'.
    Multiple choice zoology endocrine system and chemical co-ordination parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

    Parathormone is secreted when there is 

    1. Increased Ca$^{2+}$ level in blood
    2. Decreased blood Ca$^{2+}$ level

    3. Increased blood sugar level

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

    The parathyroid glands secrete a peptide hormone called parathyroid hormone or parathormone (PTH). The release of parathromone is regulated by the circulating levels of calcium ($Ca^{2+}$) ions in the blood. PTH plays an important role in calcium balance of the body. It maintains the calcium balance between the blood and other tissues. When the calcium level in the blood decreases, parathyroid hormone is released in order to increase the calcium level in the blood. PTH acts on bones and other skeletal structure and mobilizes the calcium ($Ca^{2+}$) from the bones into the blood. This is called bone resorption/dissolution/demineralization. The parathromone also increases the reabsorption of calcium by the renal tubules and absorption of calcium from the digested food. Hence, PTH (parathormone) is a hypercalcemic hormone that increases the blood calcium levels.

    Multiple choice zoology endocrine system and chemical co-ordination parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

    Choose the correct answer from the alternatives given.
    Parathyroid hormone (PTH) and calcitonin (CT) control the levels of which of the following ions in blood?

    1. Calcium

    2. Sodium

    3. Potassium

    4. Chloride
    Reveal answer Fill a bubble to check yourself
    A Correct answer
    Explanation

    The thyroid gland secretes a protein hormone called thyrocalcitonin (TCT) which regulates the blood calcium levels. Parathyroid hormone (PTH) increases the calcium levels in the blood. It also stimulates reabsorption of calcium by the renal tubules and increases calcium absorption from the digested food.

    So the correct answer is calcium.

    Multiple choice zoology endocrine system and chemical co-ordination parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

    Hypercalcemic hormone is 

    1. Thyroxine

    2. Tri-iodo-thyronine

    3. Parathormone

    4. Thyrocalcitonin
    Reveal answer Fill a bubble to check yourself
    C Correct answer
    Explanation

    Parathormone is a hypercalcemic hormone that increases the blood calcium levels. The parathyroid glands secrete a peptide hormone called parathyroid hormone or parathormone (PTH). The release of parathromone is regulated by the circulating levels of calcium ($Ca^{2+}$) ions in the blood. PTH plays an important role in calcium balance of the body. It maintains the calcium balance between the blood and other tissues. When the calcium level in the blood decreases, parathyroid hormone is released in order to increase the calcium level in the blood. PTH acts on bones and other skeletal structure and mobilizes the calcium ($Ca^{2+}$) from the bones into the blood. This is called bone resorption/dissolution/demineralization. The parathromone also increases the reabsorption of calcium by the renal tubules and absorption of calcium from the digested food.

    Multiple choice zoology endocrine system and chemical co-ordination parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

    Choose the correct answer from the alternatives given.
    Parathyroid hormone (PTH) regulates:

    1. calcium balance between blood and tissues

    2. glucose balance between blood and tissues

    3. regulates sleep

    4. regulates temperature
    Reveal answer Fill a bubble to check yourself
    A Correct answer
    Explanation

    The parathyroid gland secretes a peptide hormone called parathyroid hormone (PTH). The secretion of PTH is regulated by the circulating levels of calcium ions. PTH increases the calcium levels in the blood. PTH also stimulates reabsorption of calcium by the renal tubules and increase calcium absorption from the digested food.

    So the correct answer is calcium balance between blood and tissue.