Biology · General Awareness

Human Endocrine System

1,395 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 zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

How many of the given hormones act on the target cells by binding to intracellular receptors?
a. Iodothyronines 

b. Somatostatin 
c. Estradiol 
d. Cortisol 
e. Oxytocin 
f. Aldosterone 

  1. Two

  2. Three

  3. Four

  4. Five
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Hormones that act on the target cells by binding to intracellular receptors are steroids. 
a. Iodothyronines - thyroid hormones
b. Somatostatin - polypeptide hormone
c. Estradiol - steroid hormone
d. Cortisol - steroid hormone
e. Oxytocin - steroid hormone
f. Aldosterone - steroid hormone

So, the correct option is C.
Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Which hormone is antagonistic to calcitonin?

  1. TSH

  2. Parathyroid

  3. Thyroxine

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

  • Parathyroid hormone (PTH) is essential for the physiologic maintenance of mineral homeostasis. 
  • PTH regulates the mineral transport in bone and kidney and through its secondary actions on mineral transport in the intestine. 
  • Calcitonin, in many ways, acts as a physiologic antagonist to PTH. Hence,  Parathyroid hormone is antagonistic to calcitonin
So, the correct answer is 'Parathyroid'.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

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.
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

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

  1. Feedback

  2. Regulating

  3. Synthesizing

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

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Which hormone stimulates the production of estrogen and progesterone?

  1. Growth hormone

  2. Antidiuretic hormone

  3. Gonadotropic hormones

  4. Thyroid-stimulating hormone
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

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
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

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.
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Feedback control for hormone can be

  1. Positive only

  2. Negative only

  3. Both A and B

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

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Most of the endocrine hormone is controlled by

  1. Negative feedback inhibition

  2. Positive feedback inhibition

  3. Competitive inhibition

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Most of the hormones, especially the hormones of the pituitary gland are controlled by the negative feedback inhibition. This system operates between endocrine gland secreting the hormone and the target cells. For example ACTH secreted by the anterior lobe of pituitary stimulates the target cells present in the adrenal gland to produce cortisol. As soon as the concentration of cortisol rises above the set point in the blood stream it acts on pituitary gland to inhibit the secretion of ACTH. Thus option A is the correct answer.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

How does chemical coordination take place in animals?

  1. Endocrine glands----> hormones-----> blood----> organs / tissues----> biochemical / physiological activity.

  2. Endocrine glands----> hormones----> biochemical / physiological activity-----> blood----> organs / tissues.

  3. Hormones----> biochemical / physiological activity-----> blood----> organs / tissues----> endocrine glands.

  4. Hormones----> biochemical / physiological activity-----> endocrine glands----> blood----> organs / tissues
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Endocrine glands----> hormones-----> blood----> organs / tissues----> biochemical / physiological activity.

Chemical coordination in multicellular organisms take place through the special chemical substances called hormones, which are produced in endocrine glands. These chemicals unlike nerve cells, reach all the cells of the body and bring about desirable changes as instructed by the brain and spinal cord. This is done by using a hormone named adrenaline. It is directly secreted into the blood and carried to different parts of the body. The heart, beats faster to supply more oxygen to our muscles. The breathing rate also increases. All these responses enable the animal body to be ready to face the situation. Such hormones constitute a second way of control and coordination.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Feed back mechanism controls

  1. Nervous system

  2. Enzyme production

  3. Time and amount of hormones released by endocrine glands

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

Most hormones are regulated by feedback mechanisms. A feedback mechanism is a loop in which a product feeds back to control its own productions. Most negative feedback loops get involved from hormone feedback mechanisms. Here the time delay occurs and hormones are released.

So, the correct option is 'Time and amount of hormones released by endocrine glands'.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Group of hormones which is released with cytoplasmic bounded receptors?

  1. Hypothalamic hormones and epinephrine

  2. Thyroid hormone and estradiol

  3. Insulin and glucagon

  4. GH and MSH
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

There are two sets of nerve cells in the hypothalamus that produce hormones.

One set sends the hormones they produce down through the pituitary stalk to the posterior lobe of the pituitary gland where these hormones are released directly into the bloodstream. These hormones are anti-diuretic hormone and oxytocin.
So, the correct option is 'Hypothalamic hormones and epinephrine.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

A feedback mechanism regulates the action of the 

  1. Hormones

  2. Lipids

  3. Cell division

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

The feedback mechanism is the process wherein the upregulation and downregulation of genes, hormones, homoeostasis and other factors are controlled. For example, if the level of sugar concentration in blood has increased feedback mechanism upregulates the hormone insulin which helps to stabilise the sugar in the blood. 

So, the correct answer is option A.

Multiple choice biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

The hormone that stimulates heart beat is

  1. Thyroxine

  2. Adrenaline

  3. Glucagon

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

Adrenaline (epinephrine) is the primary hormone released during stress that stimulates the heart to beat faster and with more force. Thyroxine also affects heart rate, but adrenaline is the classic stimulator for immediate heart rate increases.

Multiple choice biology digestive system of human digestive glands liver pancreas

The cells which occupy only 5% of the islets are known as 

  1. Alpha cells

  2. Beta cells

  3. Gamma cells

  4. Both of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The islets of Langerhans are the cells in the pancreas. These cells are responsible for the endocrine functions of the pancreas. There are three type of cells, alpha cells, beta cells and gamma cells. The gamma cells are known delta cells. These cells comprise only 5% of the islets cells. These cells are responsible for the production of somatostatin hormone.

Thus, the correct answer is option C.