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.

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Human Endocrine System Questions

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Which one of the following hormones stimulates the breakdown of glycogen in the liver into glucose?

  1. Insulin

  2. Adrenaline

  3. Glucagon

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

A.Insulin – hormone stimulates the breakdown of glycogen in the liver into glucose.

B.Adrenaline – hormone increasing the heart rate, increasing blood pressure, expanding the air passages of the lungs, enlarging the pupil in the eye (see photo), redistributing blood to the muscles and altering the body's metabolism, so as to maximise blood glucose levels (primarily for the brain).

C.Glucagon - The pancreas releases glucagon when the concentration of insulin (and indirectly glucose) in the bloodstream falls too low. Glucagon causes the liver to convert stored glycogen into glucose, which is released into the bloodstream. High blood-glucose levels, on the other hand, stimulate the release of insulin.

D.Thyroxine - It plays vital roles in digestion, heart and muscle function, brain development and maintenance of bones.

So, the correct option is ‘Insulin’.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

In mammals, prolactin stimulates the production of

  1. progesterones

  2. milk

  3. mucus in the digestive tract

  4. digestive enzymes in the small intestine
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
(A) Progesterone supports a pregnancy. It also acts on the mammary glands and stimulates the formation of alveoli (sac-like structures which store milk) and milk secretion.
(B) Prolactin regulates the growth of the mammary glands and formation of milk in them. 
(C) Mucus in the digestive tract helps in lubricating and adhering the masticated food particles into a bolus.
(D) Digestive enzymes in small intestine such as chymotrypsinogen, amylases, lipases, and nucleases. Trypsinogen is activated by an enzyme, enterokinase, secreted by the intestinal mucosa into active trypsin, which in turn activates the other enzymes in the pancreatic juice.
So the correct option is milk.
Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Choose the correct answer from the alternatives given.
Which of the following hormone initiates secretion of milk?

  1. Prolactin

  2. Luteinizing hormone

  3. Somatotrophic hormone

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

(A) Prolactin regulates the growth of the mammary glands and formation of milk in them. 

(B) Leutinizing hormone stimulates gonadal activity and hence are called gonadotropin.
(C) Somatotrophic hormone or Growth hormone is a peptide hormone that stimulates growth, cell reproduction etc.
(D) Progesterone supports a pregnancy. It also acts on the mammary glands.
So the correct answer is prolactin.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Choose the correct answer from the alternatives given.
Which of the following hormones is incorrectly paired with its action?

  1. Oxytocinstimulates uterine contraction in childbirth

  2. Thyroxinestimulates metabolic processes

  3. Insulinstimulates glycogen breakdown in liver

  4. ACTHstimulates release of glucocorticoids by adrenal cortex
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

(A) Oxytocin initiates vigorous uterine contractions in females at the time of the childbirth, milk secretion by mammary glands, contraction of smooth muscles.

(B) Thyroxine is primarily responsible for regulation of metabolism.
(C) Insulin stimulates conversion of glucose to glycogen (glycogenesis).
(D) ACTH stimulates the synthesis and secretion of steroid hormones called glucocorticoids. 
So the correct answer is insulin stimulates glycogen breakdown in liver.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Choose the correct answer from the alternatives given.
One of the chief differences between pheromones and local hormones is:

  1. the distance over which they act

  2. that one is a chemical messenger and the other is not

  3. that one is made by invertebrates and the other is made by vertebrates

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

Local hormones - A number of hormones are secreted by the cells but not in glands and widely dispersed in the body are called local hormones. Example are histamine, prostaglandins, etc.

Pheromones are chemicals used for communication amongst the organism of the same species. 
So the correct answer is the distance over which they act. 

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Choose the correct answer from the alternatives given.
Which hormone stimulates secretion of milk in mammary glands?

  1. TSH

  2. Prolactin

  3. Vasopressin

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

(A) Thyroid stimulating hormone (TSH) promotes growth and function if thyroid gland. 

(B) Prolactin hormone stimulates lactation (milk production) and has a direct effect on the breasts immediately after parturition.
(C) Vasopressin or antidiuretic hormone (ADH) acts mainly at the kidney and stimulates resorption of water and electrolytes by the distal tubules and thereby reduce the loss of water through urine (diuresis). 
(D) Thyroxine is primarily responsible for regulation of metabolism.
So the correct answer is vasopressin.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Choose the correct answer from the alternatives given.
Which of the following is not an accurate statement about hormones?

  1. Hormones are chemical messengers that travel to target cells through the circulatory system

  2. Hormones often regulate .homeostasis through antagonistic functions

  3. Hormones of the same chemical class usually have the same general function

  4. Hormones are often regulated through feedback loops
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hormones are nonnutrient chemicals which act as intercellular messengers and are produced in trace amounts. All hormones produce their specific effects on target tissue/cells by binding to the specific proteins called as hormone receptors. The normal functioning of endocrine glands and the level of hormones in the body needs to be regulated. This is possible through a feedback mechanism.

So the correct answer is hormones of the same chemical class usually have the same general function.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Choose the correct answer from the alternatives given.
Second messengers include:

  1. steroid hormones

  2. cyclic AMP

  3. protein hormones

  4. both (a) and (b)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hormones which interact with membrane-bound receptors normally do not enter the target cell but generate second messengers (eg, cyclic AMP, IP3, Calcium Ions etc) which in turn regulate cellular metabolism. Hormones which interact with intracellular receptors (eg, steroid hormones, iodothyronines, etc) mostly regulate gene expressions or chromosome function by the interaction of hormone receptor complex with the genome. 

So the correct answer is cyclic AMP.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Choose the correct answer from the alternatives given.
Which organ does not synthesize hormones?

  1. Heart

  2. Adrenal cortex

  3. Anterior pituitary

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

Endocrine gland lack ducts and are called ductless glands. Their secretions are called hormones. Adrenal cortex secrets many hormones commonly called as corticoids. Anterior pituitary secretes many hormones such as GH, PRL, TSH, ACTH etc. The pineal gland secretes three hormones namely, melatonin, serotonin, adrenoglomerulotropin.

So the correct answer is the heart. 

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Choose the correct answer from the alternatives given.
Human sex hormones are classified as:

  1. amino acids

  2. lipids

  3. triacyiglycerols

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

Human sex hormone is steroid hormones. The natural steroid hormones are generally synthesized from cholesterol in the gonads and adrenal glands. These forms of hormones are lipids. 

So the correct answer is lipids.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Choose the correct answer from the alternatives given.
Which of the following hormones is called an antidiuretic hormone?

  1. Glucagon

  2. Prolactin

  3. Vasopressin

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

(A) Glucagon acts mainly on the liver cells and stimulates glycogenolysis resulting in increased blood sugar (hyperglycemia).

(B) Prolactin regulates the growth of the mammary glands and formation of milk in them. 
(C) Vasopressin or antidiuretic hormone (ADH) acts mainly at the kidney and stimulates resorption of water and electrolytes by the distal tubules and thereby reduce the loss of water through urine (diuresis). 
(D) Cortisone is the main glucocorticoid.
So the correct answer is vasopressin.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Which of the following statements is correct in relation to the endocrine system?

  1. Non-nutrient chemicals produced by the body in trace amount that act as intercellular messenger are known as hormones

  2. Releasing and inhibitory hormones are produced by the pituitary gland

  3. Adenohypophysis is under direct neural regulation of the hypothalamus

  4. Organs in the body like gastrointestinal tract, heart, kidney and liver to not produce any hormone
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The endocrine system consists of organ, tissue and cells that produce a small amount of non-nutrient chemicals which sends signals to other cells or acts as an intercellular messenger. These chemicals are known as hormones which are transported to their target site through blood.

So the correct answer is 'Non-Nutrient chemicals produced by the body in trace amount that acts as intercellular messenger are known as hormones'.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Which of the following statements regarding hormones is incorrect?

  1. Hormones are non-nutrient chemicals which acts as intercellular messengers

  2. Hormones are molecules of low molecular weight and are produced in traces

  3. Hormones provide energy and also effect growth and metabolic activities of target cell

  4. Many hormones are produced in inactive form
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hormones do not provide energy or building materials but they effect growth, differentiation and metabolic activities of their target cell.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Choose the correct answer from the alternatives given.
Steroid hormones mediate their action by:

  1. activating adenylate cydase

  2. activating gene expression

  3. binding to the surface membrane of the cells

  4. inhibiting an enzyme
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Steroid hormones and thyroid hormones do not bind to the cell surface receptors. Being lipid soluble, these are able to enter the cells and their nuclei and influence the gene action. The hormone binds to the receptors forming a hormone-receptor complex. It binds to the transcription factors that in turn to DNA and a particular gene is activated. Their transcription leads to the synthesis of a specific protein to influence the metabolism of the recipient cell. Thus, the peptide hormones activate existing enzymes in the cell while steroid hormones bring about the synthesis of new enzymes.

So the correct answer is activating gene expression.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Which of these is a correct statement? 

  1. Neurons regulate endocrine activity but not vice versa.

  2. Endocrine glands regulate neural activity and nervous system regulates endocrine glands.

  3. Neither hormones control neural activity nor neurons control endocrine activity.

  4. Endocrine glands regulate neural activity but not vice versa.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Nervous system is a coordinated network of nerve cells and fibres by which nerve impulses are transmitted throughout the body.
  • Endocrine system consists of glands that produce hormones.
In our body, nervous system and endocrine system jointly integrate all the activities as nervous system directs endocrine system to secrete hormones that act on the target organs.
So, the correct answer is 'Endocrine glands regulate neural activity and nervous system regulates endocrine glands.'.