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Q1. Which one of the following part is an endocrine gland?

• Pars radiata
• Brunner's glands
• Juxtaglomerulus
• Crypts of Lieberkühn

Solution

Cells of the juxtaglomerulus secrete erythropoietin which stimulates the process of formation of red blood cells, i.e. erythropoiesis.

Q2. Which of the following is a hormone of the kidney?

• Estradiol
• Epinephrine
• Renin
• Aldosterone

Solution

Cells close to the glomeruli in the cortex of the kidneys are endocrine. They secrete a hormone called renin.

Q3. Gastric secretion is stopped by the hormone

• Enterogastrone
• Gastrin
• Pancreozymin
• Cholecystokinin

Solution

Enterogastrone is secreted by the mucosa of the duodenum; it inhibits the secretion of gastric juices and decreases gastric movements.

Q4. When both ovaries are removed from rat, which hormone is decreased in blood?

• Oxytocin
• Prolactin
• Oestrogen
• Gonadotropin-releasing factor

Solution

If both ovaries are removed from rat, then the blood plasma level of oestrogen will be affected as it is produced by the theca interna cells of the Graafian follicles.

Q5. Which of the following hormones contain iodine?

• Thyroxine
• Insulin
• Testosterone
• Adrenaline

Solution

Iodine is a part of thyroxine hormone. There are four iodine molecules per one molecule of thyroxine.

Q6. Occurrence of Leydig cells and their secretion is

• Ovary and oestrogen
• Liver and cholesterol
• Pancreas and glucagon
• Testis and testosterone

Solution

Leydig cells are stimulated to produce male sex hormones, androgens by ICSH of the anterior pituitary. Testosterone is the main androgen and is a steroid hormone.

Q7. Select the answer which correctly matches the endocrine gland with the hormone it secretes and its deficiency symptom.  

• Endocrine gland     Hormone     Function/deficiency symptoms     Posterior pituitary     Growth hormone (GH)     Oversecretion stimulates abnormal growth        
• Endocrine gland     Hormone     Function/deficiency symptoms     Thyroid gland     Thyroxine     Lack of iodine in the diet results in goitre        
• Endocrine gland     Hormone     Function/deficiency symptoms     Corpus luteum     Testosterone     Stimulates spermatogenesis        
• Endocrine gland     Hormone     Function/deficiency symptoms     Anterior pituitary     Oxytocin     Stimulates uterus contraction during childbirth        

Solution

The thyroid gland secretes thyroxine. Synthesis of thyroxine requires iodine. Hence, lack of iodine results in hypothyroidism deficiency, i.e. simple goitre.  

Q8. Which of the following is not paired correctly?  

• Myxoedema - Swollen facial tissues  
• Cretinism - Mentally retarded  
• Grave's disease - Exophthalmos  
• Parathyroid - Tetany  
• Insulin - Raise blood glucose  

Solution

Insulin is secreted by the β-cells of the pancreas. Insulin lowers the blood sugar levels by converting it into glycogen and increasing its uptake by other tissues.  

Q9. Hormones are called chemical signals which stimulate specific target tissues. Their specificity is due to the presence of signal receiving 'receptors' only in the respective target tissues. Where are these receptors present in case of hormones of protein nature?

• Extracellular matrix
• Blood
• Plasma membrane
• Nucleus

Solution

The hormones of protein nature cannot cross the plasma membrane. Hence, these hormones bind on the protein receptors present on the plasma membrane. As soon as they bind to the receptors, secondary messengers are activated in the cell which express the effects of hormones.

Q10. Excess of which of the following hormones causes Cushing's syndrome?  

• Thyroxine  
• Cortisol  
• Adrenaline  
• Noradrenaline  

Solution

Cushing’s syndrome is caused by the high level of cortisol secreted by the adrenal cortex.     It results in high blood pressure, bone loss, diabetes, Na⁺-K⁺ imbalance of blood plasma etc.  

Q11. The corpus luteum secretes a hormone called

• Prolactin
• Progesterone
• Aldosterone
• Testosterone

Solution

The corpus luteum is a yellowish mass left after the ovulation of the mature ovarian follicle. It secretes progesterone which acts on the uterus and prepares its endometrial lining for pregnancy. It also acts on mammary glands.

Q12. The hormone responsible for ovulation is

• LH
• FSH
• Progesterone
• Testosterone

Solution

Luteinising hormone (LH) is secreted by the pars distalis or anterior pituitary. LH stimulates the synthesis of androgens from the testes in males, while it is responsible for ovulation and the release of mature Graafian follicle, formation of the corpus luteum etc. in females. Low LH levels result in the failure of ovulation.

Q13. Which one of the following hormones never reaches the cytoplasm?

• Oestrogen
• FSH
• Progesterone
• Testosterone

Solution

FSH (i.e. follicle-stimulating hormone) is a glycoprotein hormone and hence is either too large in size or too charged to cross the plasma membrane. Hence, it binds to the protein receptors present on the cell membrane and activates the secondary messengers within the cell to produce its effect. Oestrogen, progesterone and testosterone are steroid hormones which are lipid-soluble and hence easily pass through the plasma membrane and enter the cytoplasm.

Q14. Which one of the following hormones is a modified amino acid?

• Prostaglandin
• Oestrogen
• Epinephrine
• Progesterone

Solution

Modified amino acids are derived from a single amino acid. Epinephrine and norepinephrine are catecholamines; both are modified amino acids derived from tyrosine.

Q15. Which of the following is an accumulation and release centre of neurohormones?

• Posterior pituitary lobe
• Intermediate lobe of the pituitary
• Hypothalamus
• Anterior pituitary lobe

Solution

All secretion by the pituitary gland is controlled by a hormonal signal from the hypothalamus. The neurohormones are secreted and accumulated by the hypothalamus.

Q16. Steroid hormones easily pass through the plasma membrane by simple diffusion because they

• Are water-soluble
• Contain carbon and hydrogen
• Enter through pores
• Are lipid-soluble

Solution

Steroid hormones are lipophilic in nature. The lipids present in the cell membranes do not prohibit the entry of lipophilic molecules in the cell. Hence, steroid hormones are easily diffused through the cell membrane.

Q17. A hormone responsible for the normal sleep-wake cycle is  

• Epinephrine  
• Gastrin  
• Melatonin  
• Insulin  

Solution

Melatonin is secreted the pineal glands. The hormone’s function is to control the biological rhythm or the diurnal rhythm of our body.  

Q18. Which one of the following is an example of negative feedback loop in humans?

• Constriction of skin blood vessels and contraction of skeletal muscles when it is too cold
• Secretion of tears after falling of sand particles into the eye
• Salivation of mouth at the sight of delicious food
• Secretion of sweat glands and constriction of skin blood vessels when it is too hot

Solution

Constriction of blood vessels and contraction of skeletal muscles because of cold is an example of negative feedback mechanism of homeostasis.

Q19. Match the source gland with its respective hormone and function and select the correct option. Gland Secretion Effect on body A Oestrogen Maintenance of secondary sexual characters Alpha cells of islets of Langerhans B Raises blood sugar level Anterior pituitary C Oversecretion leads to gigantism  

• A B C ovary glucagon Growth hormone
• A B C placenta insulin vasopressin
• A B C ovary insulin calcitonin
• A B C placenta glucagon calcitonin

Solution

Gland Secretion Effect on body A (Ovary) Oestrogen Maintenance of secondary sexual characters Alpha cells of Islets of Langerhans B (Glucagon) Raises blood sugar level Anterior pituitary C (Growth hormone) Oversecretion leads to gigantism  

Q20. Which one of the following is not a function of insulin?  

• Initiates the conversion of glycogen to glucose  
• Initiates the formation of hepatic glycogen from     excess of glucose  
• Increases the permeability of cell membrane to glucose  
• Increases the oxidation of glucose in the cells  

Solution

Insulin is a peptide hormone secreted by the β-cells of the pancreas. It is responsible for lowering the blood glucose levels. Hence, it is involved in the conversion of blood glucose into glycogen.  

Q21. Prostaglandins are

• Amino acid
• Steroid
• Fatty acid
• Carbohydrate

Solution

Prostaglandins are fatty acids derived from arachidonic acid. They are released by every organ, and they perform various roles in immunity, reproduction, digestion, respiration, circulation, excretion etc.

Q22. Which of the following diseases is not related to the thyroid gland?

• Myxoedema
• Cretinism
• Acromegaly
• Goitre

Solution

The growth hormone is secreted by the anterior lobe of the pituitary gland. Acromegaly is a disorder caused in adults due to the over secretion of growth hormone. In acromegaly, the bones of the jaw protrude and the palms and feet become broad. Facial features thicken.

Q23. Which of the following pairs of hormones are examples of those which can easily pass through the cell membrane of the target cell and bind to a receptor inside it (Mostly in the nucleus)?

• Insulin, glucagon
• Thyroxin, insulin
• Somatostatin, oxytocin
• Cortisol, testosterone

Solution

Cortisol and testosterone are steroid hormones. Steroid hormones are lipophilic in nature. The lipids present in the cell membranes do not prohibit the entry of lipophilic molecules in the cell. Hence, steroid hormones easily diffuse through the cell membrane and can bind to the receptors in the cytoplasm or nucleus.

Q24. All the following tissues in mammals except one consist of a central 'medullary' region surrounded by a cortical region. Mark the wrong entry.

• Ovary
• Adrenal
• Liver
• Kidney

Solution

Ovaries contain microscopic structures called ovarian follicles. Each ovarian follicle contains an egg cell surrounded by one or more layers of granulose cells depending on the maturity of the follicle.

Q25. Damage to the thymus in a child may lead to  

• A reduction in haemoglobin content of blood  
• A reduction in stem cell production  
• Loss of antibody-mediated immunity  
• Loss of cell-mediated immunity  

Solution

The thymus secretes the hormone thymosin which stimulates the differentiation of T-lymphocytes. T-lymphocytes provide cell-mediated immunity. In old age, the thymus gland degenerates; hence, immune responses in old people are weak.     Hence, damage to the thymus gland in a child will hamper the differentiation of T-lymphocytes which provide immunity.  

Q26. Which of the following glands is not an endocrine gland?

• Pancreas
• Pineal gland
• Testes
• Parotid gland

Solution

The parotid gland is a salivary gland which releases its secretion into the mouth through a duct. The pineal gland and testes are endocrine glands, while the pancreas is an exocrine as well as an endocrine gland.

Q27. Who is known as the ‘father of endocrinology’?

• R. H. Whittaker
• Pasteur
• Einthoven
• Thomas Addison

Solution

Thomas Addison was the first person who showed the relation between the secretion of the adrenal gland and Addison’s disease named after him.

Q28. Choose the correct answer among the following options: Epinephrine Increase in muscle growth Testosterone Decrease in blood pressure Glucagon Decrease in liver glycogen content Atrial natriuretic factor Increase in heart beat  

• A-ii, B-i, C-iii, D-iv
• A-iv, B-i, C-iii, D-ii
• A-i, B-ii, C-iii, D-iv
• A-i, B-iv, C-ii, D-iii

Solution

Epinephrine iv. Increase in heart beat Testosterone i. Increase in muscle growth   Glucagon iii. Decrease in liver glycogen content Atrial natriuretic factor ii. Decrease in blood pressure  

Q29. The fight and flight hormone is

• Adrenaline
• Thyroxine
• ADH
• Oxytocin

Solution

Adrenaline and noradrenaline are secreted by the adrenal gland. Both hormones show antagonistic effects and are responsible for the fight and flight response of the body. Adrenaline initiates the stress responses in the body. It mainly acts on smooth muscles, cardiac muscles, blood vessels, skeletal muscles and fat cells. It increases heart rate, blood pressure, metabolic rate, dilates blood vessels and increases the breathing rate and hence oxygen consumption and glucogenesis (i.e. the formation of glucose by the breakdown of liver glycogen), elevating the blood glucose levels.

Q30. Which of the following is a hormone of the heart?

• Renin
• Calcitrol
• Erythropoietin
• ANF

Solution

The hormone of the heart is called atrial natriuretic factor (ANF).

Q31. Which of the following hormones has been found identical with cholecystokinin?

• Secretin
• Pancreozymin
• Duocrinin
• Gastrin

Solution

Pancreozymin is a hormone secreted by duodenal mucosa which is identical with cholecystokinin.

Q32. Which of the following hormones does not contain a polypeptide?

• Insulin
• Antidiuretic hormone
• Prostaglandin
• Oxytocin

Solution

Prostaglandins are fatty acids derived from arachidonic acid. They are released by every organ, and they perform various roles in immunity, reproduction, digestion, respiration, circulation, excretion etc. Because they perform a number of functions and are secreted by many organs, they are called paracrine secretions.

Q33. Which hormone causes dilation of blood vessels, increased oxygen consumption and glucogenesis?

• ACTH
• Insulin
• Adrenaline
• Glucagon

Solution

Adrenaline elevates the glucose level in the blood stream by glucogenesis which is accompanied by an increase in oxygen consumption, body temperature and heat production. It also causes an increase in the flow of blood by dilating the blood vessels.

Q34. The endocrine part of pancreas is

• Islets of Langerhans
• Hepatic lobules
• Serosa
• Centroacinar cells

Solution

The islets of Langerhans were first found by a German medical student Paul Langerhans. There are three kinds of islets of Langerhans found in the pancreas - α-cells, β-cells and δ-cells. α-cells secrete glucagon, β-cells secrete insulin and δ-cells secrete somatostatin.

Q35. Gonadotropic hormones are produced in the

• Interstitial cells of the testes
• Adrenal cortex
• Adenohypophysis of the pituitary
• Posterior part of the thyroid

Solution

The gonadotropic hormones such as FSH and ICSH are secreted by the anterior lobe of the pituitary—the adenohypophysis.

Q36. Chemically, hormones are

• Proteins only
• Steroids only
• Biogenic amines only
• Proteins, steroids and biogenic amines

Solution

On the basis of chemical nature, hormones are categorised as steroids (cortisol), proteins (insulin) and biogenic amines (epinephrine).

Q37. An adenohypophysis hormone which is regulated by the feedback mechanism is

• Oxytocin
• TSH
• Vasopressin
• Cortisone
• Calcitonin

Solution

Thyroid-stimulating hormone (TSH) is secreted by the adenohypophysis. It controls the secretion of thyroid hormones by the thyroid gland. To maintain the levels of thyroxine in blood under normal, the secreted thyroxine shows a negative effect of the adenohypophysis which inhibits the secretion of TSH.

Q38. Listed below are hormones of anterior pituitary origin. Tick the wrong entry.  

• Growth hormone  
• Follicle-stimulating hormone  
• Oxytocin  
• Adrenocorticotropic hormone  

Solution

Oxytocin is secreted by the posterior pituitary lobe. It is a peptide hormone and shows its effects on the uterine muscles and mammary glands.  

Q39. Anti-diuretic hormone is also known as

• Secretin
• Vasopressin
• Gastrin
• Renin

Solution

Anti-diuretic hormone is secreted by the neurohypophysis of the pituitary gland. Because it stimulates the constriction of blood vessels and results in an increase in blood pressure, it is also called vasopressin.

Q40. Which one of the following pairs correctly matches a hormone with a disease resulting from its deficiency?

• Luteinising hormone - Failure of ovulation
• Insulin - Diabetes insipidus
• Thyroxine - Tetany
• Parathyroid hormone - Diabetes mellitus

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