Endocrine Glands Practice Questions
20 free Endocrine Glands practice questions for the NCERT Biology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
The pituitary gland is located in a bony cavity of the skull called:
- A Foramen magnum
- B Sella turcica
- C Glenoid cavity
- D Acetabulum
Correct answer: Sella turcica
The pituitary gland is attached to the hypothalamus by a stalk and resides in a depression of the sphenoid bone known as the sella turcica. This anatomical position provides significant protection to the 'master gland'.
Which portion of the pituitary gland is responsible for the secretion of Melanocyte Stimulating Hormone (MSH)?
- A Pars distalis
- B Pars intermedia
- C Pars nervosa
- D Neurohypophysis
Correct answer: Pars intermedia
In humans, the pars intermedia is almost merged with the pars distalis. It is specifically responsible for secreting MSH, which regulates the pigmentation of the skin.
Hypersecretion of Growth Hormone (GH) in adults, especially in middle age, can lead to severe disfigurement called:
- A Pituitary gigantism
- B Dwarfism
- C Acromegaly
- D Hypothyroid cretinism
Correct answer: Acromegaly
While excess GH in childhood causes gigantism, hypersecretion in adults leads to acromegaly. This condition is characterized by the disproportionate overgrowth of bones in the face, hands, and feet.
Which hormone is synthesized by the hypothalamus but stored and released by the neurohypophysis?
- A Prolactin
- B Oxytocin peptide
- C Luteinizing hormone
- D Thyroid-stimulating hormone
Correct answer: Oxytocin peptide
The neurohypophysis (posterior pituitary) does not synthesize its own hormones. Instead, it stores and releases oxytocin and vasopressin, which are produced by hypothalamic neurons.
The thyroid gland is composed of two lobes located on either side of the:
- A Esophagus
- B Trachea
- C Jugular vein
- D Larynx
Correct answer: Trachea
The thyroid gland is situated in the neck, with its two lobes flanking the trachea. The lobes are interconnected by a thin flap of connective tissue called the isthmus.
Which element is essential for the normal rate of hormone synthesis in the thyroid?
- A Iron
- B Calcium
- C Iodine
- D Sodium
Correct answer: Iodine
Iodine is a critical component of thyroid hormones like $T_3$ and $T_4$. A deficiency in dietary iodine leads to hypothyroidism and the enlargement of the thyroid gland, commonly known as goitre.
Hypothyroidism during pregnancy can cause 'Cretinism' in the baby, which is characterized by:
- A High IQ and accelerated growth rate
- B Mental retardation and abnormal skin
- C Increased metabolic rate and weight loss
- D Early onset of puberty in infants
Correct answer: Mental retardation and abnormal skin
Thyroid hormones are vital for fetal brain development and growth. Deficiency during pregnancy leads to cretinism, resulting in stunted growth, mental retardation, low intelligence quotient, and deaf-mutism.
The hormone 'Thyrocalcitonin' (TCT) is secreted by the thyroid gland and functions to:
- A Increase blood glucose levels
- B Lower blood calcium levels
- C Regulate sleep-wake cycles
- D Stimulate RBC production
Correct answer: Lower blood calcium levels
Thyrocalcitonin is a protein hormone secreted by the parafollicular cells of the thyroid. It plays a significant role in calcium homeostasis by reducing blood calcium levels when they are too high.
The adrenal cortex is divided into three layers. Name the outermost layer:
- A Zona fasciculata
- B Zona reticularis
- C Zona glomerulosa
- D Adrenal medulla
Correct answer: Zona glomerulosa
The adrenal cortex has three zones: Zona glomerulosa (outer), Zona fasciculata (middle), and Zona reticularis (inner). The Zona glomerulosa is primarily responsible for secreting mineralocorticoids like aldosterone.
Which hormones are referred to as the 'hormones of Fight or Flight'?
- A Insulin and Glucagon
- B Adrenaline and Noradrenaline
- C Cortisol and Dehydroepiandrosterone
- D Estrogen and Progesterone
Correct answer: Adrenaline and Noradrenaline
Adrenaline (epinephrine) and noradrenaline (norepinephrine) are secreted by the adrenal medulla in response to stress. They rapidly increase alertness, pupillary dilation, heart rate, and breakdown of glycogen.
Glucocorticoids, particularly cortisol, are involved in which of the following processes?
- A Promoting glycogen storage and stimulating immune activity
- B Stimulating gluconeogenesis and suppressing inflammation
- C Inhibiting gluconeogenesis and promoting anabolic pathways
- D Stimulating insulin release and immune enhancement
Correct answer: Stimulating gluconeogenesis and suppressing inflammation
Cortisol stimulates the production of glucose from non-carbohydrate sources (gluconeogenesis) and lipolysis. It also acts as an immunosuppressant and anti-inflammatory agent in the body.
Aldosterone acts mainly at the renal tubules to stimulate the reabsorption of:
- A Potassium and phosphate ions
- B Sodium ions and water
- C Glucose and amino acids
- D Urea and uric acid
Correct answer: Sodium ions and water
Aldosterone is the primary mineralocorticoid that regulates electrolyte balance. It promotes the reabsorption of Na+ and water while stimulating the excretion of K+ and phosphate ions.
The endocrine part of the pancreas consists of 'Islets of Langerhans'. Which cells secrete glucagon?
- A Alpha cells
- B Beta cells
- C Delta cells
- D F cells
Correct answer: Alpha cells
There are about 1 to 2 million Islets of Langerhans in a normal human pancreas. The alpha cells within these islets secrete the hyperglycemic hormone glucagon.
Insulin is a peptide hormone that primarily acts on ________ and ________ to increase glucose uptake.
- A Neurons and Nephrons
- B Hepatocytes and Adipocytes
- C Erythrocytes and Leucocytes
- D Osteocytes and Chondrocytes
Correct answer: Hepatocytes and Adipocytes
Insulin targets liver cells (hepatocytes) and fat cells (adipocytes). It enhances the cellular uptake and utilization of glucose, thereby reducing blood sugar levels (hypoglycemia).
Diabetes mellitus is characterized by which of the following?
- A Hypoglycemia and a complete absence of ketone bodies
- B Hyperglycemia and loss of glucose through urine
- C Low blood pressure and significant weight gain
- D Marked increase in insulin sensitivity and glucose uptake
Correct answer: Hyperglycemia and loss of glucose through urine
Prolonged hyperglycemia leads to Diabetes mellitus. This condition causes the excretion of glucose in the urine (glycosuria) and the formation of harmful metabolic byproducts called ketone bodies.
Which hormone stimulates the 'Sertoli cells' in males for the process of spermiogenesis?
- A Luteinizing Hormone (LH)
- B Follicle Stimulating Hormone (FSH)
- C Androgens such as testosterone
- D Melatonin from the pineal gland
Correct answer: Follicle Stimulating Hormone (FSH)
In males, FSH acts on the Sertoli cells of the testes to stimulate the secretion of factors that help in the transformation of spermatids into mature spermatozoa (spermiogenesis).
The 'corpus luteum' is formed after ovulation and primarily secretes:
- A Estrogen alone
- B Progesterone
- C Androgens and DHEA
- D Inhibin and activin
Correct answer: Progesterone
Following ovulation, the ruptured Graafian follicle transforms into a temporary endocrine structure called the corpus luteum. It secretes high levels of progesterone, which is essential for maintaining the uterine lining during pregnancy.
Underproduction of hormones by the adrenal cortex can lead to acute weakness and fatigue, a condition known as:
- A Cushing's syndrome
- B Addison's disease
- C Grave's disease
- D Diabetes insipidus
Correct answer: Addison's disease
Addison's disease occurs when the adrenal cortex fails to produce sufficient cortisol and aldosterone. It alters carbohydrate metabolism and causes extreme fatigue, weight loss, and low blood pressure.
Which gland is often called the 'biological clock' because it secretes melatonin to regulate the 24-hour diurnal rhythm?
- A Thymus gland
- B Pineal gland
- C Pituitary gland
- D Thyroid gland
Correct answer: Pineal gland
The pineal gland, located on the dorsal side of the forebrain, secretes melatonin. This hormone regulates sleep-wake cycles, body temperature, and even influences metabolism and menstrual cycles.
Hormones that interact with intracellular receptors (like steroid hormones) mostly regulate gene expression by forming a:
- A Cyclic AMP signaling complex
- B Hormone-receptor complex
- C Secondary messenger cascade
- D G-protein coupled signaling unit
Correct answer: Hormone-receptor complex
Steroid hormones are lipid-soluble and can cross the cell membrane. They bind to intracellular receptors to form a hormone-receptor complex that interacts with the genome (DNA) to trigger physiological responses.