Endocrine System Archives

1. In human body, the hormone which is secreted into blood and which cont

In human body, the hormone which is secreted into blood and which controls the rate of heart beat is

Adrenaline

Thyroxine

Insulin

Testosterone

This question was previously asked in

UPSC CAPF – 2020

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Adrenaline (also known as epinephrine) is a hormone secreted by the adrenal glands that increases the rate and force of heart beats, among other effects.

Adrenaline is part of the body’s “fight or flight” response, preparing the body for physical exertion by increasing cardiovascular activity.

Thyroxine regulates metabolism. Insulin regulates blood sugar levels. Testosterone is a primary male sex hormone involved in development and reproduction.

2. Which one of the following statements regarding insulin hormone is

Which one of the following statements regarding insulin hormone is correct?

Insulin is a protein hormone which is not produced in human body.

Insulin is a steroid hormone which is produced in human body.

Insulin is a cholesterol-driven hormone given to human.

Insulin is a protein hormone which is produced in human body.

This question was previously asked in

UPSC CAPF – 2018

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Insulin is a hormone produced by the beta cells of the islets of Langerhans in the pancreas. It is crucial for regulating blood glucose levels by promoting glucose uptake and storage in various tissues. Chemically, insulin is classified as a peptide hormone (a type of protein hormone), composed of amino acids. It is not a steroid hormone, which are derived from cholesterol. Insulin is naturally produced in a healthy human body. People with type 1 diabetes, whose beta cells are destroyed, require exogenous insulin administration, but this does not mean it is not produced in the human body under normal circumstances.
Let’s evaluate the options:
A) Insulin is a protein hormone which is not produced in human body. Incorrect, it is produced in the human body.
B) Insulin is a steroid hormone which is produced in human body. Incorrect, it is produced but is a protein hormone.
C) Insulin is a cholesterol-driven hormone given to human. Incorrect, it is a protein hormone, not cholesterol-driven, though it is given to treat diabetes.
D) Insulin is a protein hormone which is produced in human body. Correct.

Insulin is a protein hormone produced by the pancreas in the human body, primarily involved in regulating blood glucose levels.

Other important hormones involved in glucose regulation include glucagon (also produced by the pancreas), which has opposite effects to insulin, raising blood glucose levels. Insulin and glucagon work together to maintain glucose homeostasis.

3. Match List I with List II and select the correct answer using the code

Match List I with List II and select the correct answer using the code given below the Lists :
List I
(Hormone)
A. Aldosterone
B. Oestrogen
C. Melatonin
D. Progesterone
List II
(Function)
1. Maintains female secondary sex characteristics
2. Controls circadian rhythm
3. Salt-retaming hormone
4. Sustains the pregnancy

Code :

	A	B	C	D
(a)	4	2	1	3
(b)	4	1	2	3
(c)	3	2	1	4
(d)	3	1	2	4

(a)

(b)

(c)

(d)

This question was previously asked in

UPSC CAPF – 2014

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Matching the hormones with their primary functions:
A. Aldosterone: This is a mineralocorticoid hormone that regulates sodium and potassium balance in the body, primarily by promoting sodium reabsorption in the kidneys. It is known as a salt-retaining hormone. (A matches 3)
B. Oestrogen (Estrogen): This is a primary female sex hormone responsible for the development and maintenance of female secondary sexual characteristics (like breast development, uterine growth, etc.) and plays a key role in the menstrual cycle. (B matches 1)
C. Melatonin: This hormone is produced by the pineal gland and plays a crucial role in regulating the body’s sleep-wake cycle, also known as the circadian rhythm. (C matches 2)
D. Progesterone: This hormone is vital for preparing the uterus for pregnancy, maintaining the uterine lining throughout pregnancy, and preventing premature contractions. It is essential for sustaining pregnancy. (D matches 4)
The correct matching is A-3, B-1, C-2, D-4.

Understanding the major roles of key hormones in the endocrine system is necessary for this question.

Aldosterone is part of the Renin-Angiotensin-Aldosterone System (RAAS). Oestrogen and Progesterone are key sex hormones produced by the ovaries, regulated by the pituitary hormones FSH and LH. Melatonin production is influenced by light exposure.

4. Which one of the following hormones increases the heartbeat in

Which one of the following hormones increases the heartbeat in mammals?

Insulin

Melatonin

Thyroxine

Adrenaline

This question was previously asked in

UPSC NDA-2 – 2022

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Adrenaline is the hormone that increases the heartbeat in mammals.

Adrenaline (also known as epinephrine) is a hormone produced by the adrenal medulla. It is released in response to stress and triggers the “fight or flight” response. One of its key effects is to increase heart rate and force of contraction, leading to increased blood pressure and cardiac output.

Insulin lowers blood glucose. Melatonin regulates sleep cycles. Thyroxine increases metabolic rate, which indirectly affects heart rate over time, but adrenaline causes a rapid increase in heart rate in response to acute stimuli.

5. Which one of the following hormones is responsible for the development

Which one of the following hormones is responsible for the development of female sexual characters ?

Prolactin

Estrogen

Oxytocin

Progesterone

This question was previously asked in

UPSC NDA-2 – 2021

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The correct answer is B) Estrogen.

Estrogen is the primary female sex hormone responsible for the development and maintenance of secondary sexual characteristics in females, such as breast development, widening of the hips, and maturation of the reproductive organs.

Prolactin is involved in milk production. Oxytocin is involved in uterine contractions during childbirth and milk let-down. Progesterone is mainly involved in preparing the uterus for pregnancy and maintaining pregnancy.

6. Thyroid gland produces a hormone called “Thyroxine” which

Thyroid gland produces a hormone called “Thyroxine” which

controls blood glucose levels.

controls ovulation.

controls metabolic rate.

maintains pregnancy.

This question was previously asked in

UPSC NDA-2 – 2019

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The correct option is C) controls metabolic rate.

Thyroxine, produced by the thyroid gland, is the main hormone responsible for regulating the body’s metabolism, including how fast the body uses energy and makes proteins.

Thyroxine (T4) and triiodothyronine (T3), the active form, affect almost every cell in the body. They increase the basal metabolic rate, influence protein synthesis, help regulate long bone growth, and play a role in neural maturation. Blood glucose levels are primarily controlled by insulin and glucagon, ovulation by FSH, LH, and estrogen, and maintenance of pregnancy mainly by progesterone.

7. Kidney secretes an enzyme, which changes plasma protein angiotensinoge

Kidney secretes an enzyme, which changes plasma protein angiotensinogen into angiotensin. The enzyme is

Renin

Nitrogenase

Hydrolase

Mono-oxygenase

This question was previously asked in

UPSC NDA-1 – 2017

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The correct answer is Renin.

Renin is an enzyme secreted by the juxtaglomerular cells of the kidneys. It plays a crucial role in the body’s Renin-Angiotensin-Aldosterone System (RAAS), which regulates blood pressure, fluid balance, and electrolyte balance. Renin initiates the cascade by cleaving angiotensinogen, a plasma protein produced in the liver, into angiotensin I.

Angiotensin I is then converted into angiotensin II, a potent vasoconstrictor and stimulator of aldosterone secretion, by the Angiotensin-Converting Enzyme (ACE), primarily found in the lungs. The RAAS pathway is vital for maintaining homeostasis and is a target for many medications used to treat hypertension and heart failure. Nitrogenase is involved in nitrogen fixation, Hydrolase is a broad class of enzymes that catalyze hydrolysis, and Mono-oxygenase is an enzyme that incorporates one atom of molecular oxygen into a substrate. None of these are directly involved in the kidney’s conversion of angiotensinogen.

8. Which endocrine gland requires iodine to synthesize a particular hormo

Which endocrine gland requires iodine to synthesize a particular hormone whose deficiency may cause goitre disease ?

Hypothalamus

Pancreas

Thymus

Thyroid gland

This question was previously asked in

UPSC NDA-1 – 2015

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The thyroid gland is an endocrine gland located in the neck that produces thyroid hormones.

Thyroid hormones (thyroxine and triiodothyronine) contain iodine atoms. Iodine is an essential micronutrient required for the synthesis of these hormones. A deficiency of iodine leads to insufficient production of thyroid hormones, which in turn causes the thyroid gland to enlarge, a condition known as goitre, in an attempt to compensate and produce more hormones.

The hypothalamus is part of the brain and controls the pituitary gland, which in turn regulates the thyroid. The pancreas produces insulin and glucagon (regulating blood sugar). The thymus is involved in immune system development. Only the thyroid gland directly synthesizes hormones requiring iodine, whose deficiency causes goitre.

9. Which one of the following hormones is essential for the uptake of glu

Which one of the following hormones is essential for the uptake of glucose by cells in the human body?

TSH

Insulin

Cortisol

This question was previously asked in

UPSC CDS-2 – 2016

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Insulin is the hormone essential for the uptake of glucose by cells in the human body.

– Insulin is a hormone produced by the beta cells of the pancreas.
– Its primary role is to regulate blood glucose levels by facilitating the uptake of glucose from the bloodstream into most cells of the body, particularly muscle, fat, and liver cells.
– Insulin binds to receptors on cell membranes, triggering the translocation of glucose transporters (like GLUT4) to the cell surface, allowing glucose to enter the cell.
– GH (Growth Hormone) has effects on metabolism, including promoting growth and cell reproduction. It can increase blood glucose levels by stimulating gluconeogenesis and inhibiting glucose uptake.
– TSH (Thyroid Stimulating Hormone) stimulates the thyroid gland to produce thyroid hormones, which regulate metabolism but are not directly involved in glucose uptake by most cells.
– Cortisol is a glucocorticoid hormone produced by the adrenal glands. It also influences glucose metabolism, typically by increasing blood glucose levels (gluconeogenesis) and reducing peripheral glucose uptake.

Diabetes mellitus is a disease characterized by high blood glucose levels resulting from either insufficient insulin production (Type 1) or the body’s cells not responding properly to insulin (Type 2).

10. Which one of the following is essential for thyroid gland to make

Which one of the following is essential for thyroid gland to make thyroxin?

NaCl

KCl

Cholesterol

Iodine

This question was previously asked in

UPSC CDS-1 – 2023

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Iodine is an essential trace element required by the thyroid gland to synthesize thyroid hormones, namely thyroxine (T4) and triiodothyronine (T3).

Iodine atoms are incorporated into the structure of the thyroxine and triiodothyronine molecules. Deficiency of iodine can lead to impaired thyroid hormone production, resulting in conditions like goiter and hypothyroidism.

The thyroid gland actively accumulates iodide ions from the blood. The synthesis of thyroid hormones involves the iodination of tyrosine residues on the protein thyroglobulin.