Tag: endocrine system in humans

Questions Related to endocrine system in humans

The cells which produces erythropoietin

  1. Juxtaglomerular cells

  2. Hepatic cells

  3. Glandular cells

  4. None of the above


Correct Option: A
Explanation:
  • Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with the peritubular capillary and proximal convoluted tubulin the cell named juxtaglomerular cells. 
  •  It is also produced in perisinusoidal cells in the liver. Hence, The cells which produce erythropoietin Juxtaglomerular cells.
  • So, the correct answer is 'Juxtaglomerular cells'.

Which of the following is NOT true about hormones?

  1. Hormones are secreted into the bloodstream.

  2. Hormones are released from exocrine glands.

  3. Hormones may be classified as peptides or steroids.

  4. Hormones usually affect a target organ.


Correct Option: B
Explanation:

Hormones are the chemical substance, released from endocrine glands. They are directly released into the blood and affect the targeted organ. They may be the peptide such as insulin or steroid such as cortisol. Thus, the correct answer is option B.

Zoologists extracted the chemical that the Japanese beetle uses to attract a mate and use it in a trap to reduce the beetle population. They are utilizing a

  1. Hormone

  2. Pesticide

  3. Enzyme

  4. Pheromone


Correct Option: D
Explanation:

A pheromone is a chemical released by one animal to affect the behaviour of another animal and thus it is used to trap the beetle to reduce their population.

A ................... mechanism regulates the action of the hormones.

  1. Feedback

  2. Regulating

  3. Synthesizing

  4. Control


Correct Option: A
Explanation:

Hormonal actions are regulated by two mechanisms: feedback and antagonistic effects of two hormones. A feedback mechanism can work as a negative or positive mechanism. The negative feedback mechanism is activated by surplus and proceeds to correct the process that caused the surplus. Therefore, increased the blood level of a certain hormone or its effect on target organ act to prevent its further release. For example, increased blood glucose level stimulates insulin secretion. The positive feedback mechanism of hormone regulation includes stimulation of release of the same hormone caused by its increased blood level. For example, the release of oxytocin is stimulated by uterine contraction during labor pain. 

Therefore, the correct answer is option A.

Which hormone stimulates the production of estrogen and progesterone?

  1. Growth hormone

  2. Antidiuretic hormone

  3. Gonadotropic hormones

  4. Thyroid-stimulating hormone


Correct Option: C
Explanation:

Gonadotropin is a hormone which stimulates production of sex hormones and development of secondary sexual characters.
Females : Ovaries : Oestrogen and Progesterone
Males : Testes (testicle) : Testosterone.

When the secretion of hormones is under the control of factors or hormones it is called as

  1. Homeostasis

  2. Feedback control

  3. Conjugation

  4. Transduction


Correct Option: B
Explanation:

When the secretion of hormone is controlled by the factors or other hormones it is called feedback control. For example, homeostasis means keeping the internal environment of the body constant. Hormones help in maintaining internal environment of the body. Thus, the correct answer is option B.

When the output of a pathway inhibits inputs to the pathway. This condition is known as

  1. Positive feedback

  2. Negative feedback

  3. Both A and B

  4. None of the above


Correct Option: B
Explanation:

An increased amount of thyroxine in the blood exerts an inhibitory effect on the hypothalamus. in such a way that less of thyroid releasing hormone (TRH) and thyroid stimulating hormone (TSH) is produced respectively. This eventually results in a decrease in thyroxine. This is called negative feedback control. 

Which among the following is the correct example of negative feedback?

  1. Regulation of blood calcium level

  2. Saliva secretion

  3. Secretion of pancreatic amylase

  4. All of the above


Correct Option: A
Explanation:

A- Levels of parathyroid hormone are regulated by a negative feedback loop by increasing blood calcium levels which further prevents the release of parathyroid hormone.

Which is an example of negative feedback?

  1. Nursing action stimulates the hypothalamus to release oxytocin that triggers mammary gland milk production.

  2. When the blood becomes dilute, ADH is no longer released from the hypothalamus.

  3. Uterine stretching sends nerve impulses to the hypothalamus that releases oxytocin that triggers uterine contraction.

  4. TRH stimulate the anterior pituitary to release thyroid-stimulating hormone.


Correct Option: B
Explanation:

When a high level of particular hormone inhibits their further secretion is called as negative feedback. As the level of water in the blood falls, negative feedback ensures that the amount of ADH rises. As the level of water in the blood rises, negative feedback ensures that the amount of ADH falls. Thus, the correct answer is option B.

Feedback control for hormone can be

  1. Positive only

  2. Negative only

  3. Both A and B

  4. None of the above


Correct Option: C
Explanation:

When the secretion of hormone is controlled by some factors or other hormones is called as feedback control. It can be both positive and negative. When the hormone secretion is amplified by its own secretion is called as positive feedback. When a high level of particular hormone inhibits their further secretion is called as negative feedback. Thus, the correct answer is option C.