Hypersecretion of growth hormone in adults does not cause further increase in height because
(a) growth hormone becomes inactive in adults
(b) epiphyseal plates close after adolescence
(c) bones loose their sensitivity to growth hormone in adults
(d) muscle fibres do not grow in size after birth
(b) Chronic hypersecretion of Growth Hormone (GH) leads to gigantism or acromegally depending on the age of the individual .
If its hypersecretion occurs before the ossification of epiphyseal plates, it causes exaggerated and prolonged growth in long bones. It results in gigantism
In adults, hypersecretion of GH leads to accromegaly. No increase in height occurs because of the ossified epiphyseal plate.
Thinking process Epiphyseal plate is responsible for the growth of bone. It closes after adolescence.
Which of the following is a temporary endocrine gland in the human body?
(a) pineal gland (b) corpus cardiacum
(c) corpus Iuteum (d) corpus allatum
(c) Corpus luteum is a temporary endocrine gland in the human body. It secretes small amount of estradiol and significant amount of progesterone hormone. In the absence of fertilisation, the corpus luteum degenerates.
GnRH, a hypothalamic hormone, needed in reproduction, acts on
(a) anterior pituitary gland and stimulates secretion of LH and oxytocin
(b) anterior pituitary gland and stimulates secretion of LH and FSH
(c) posterior pituitary gland and stimulates secretion of oxytocin and FSH
(d) posterior pituitary gland and stimulates secretion of LH and relaxin
(b) GnRH is a hypothalamic hormone. It stimulates the anterior lobe of pituitary gland to secrete LH and FSH.
Graves disease is caused due to?
(a) hyposecretion of thyroid gland
(b) hypersecretion of thyroid gland
(c) hyposecretion of adrenal gland
(d) hypersecretion of adrenal gland
(b) Graves disease or hyperthyroidism is caused due to the secretion of excessive amount of thyroid hormone by the thyroid gland. i.e. hyperthyroidism.
Name a peptide hormone which acts mainly on hepatocytes, adipocytes and enhances cellular glucose uptake and utilisation.
(a) Insulin is the peptide hormone which enhances the uptake of glucose molecules by liver cells (hepatocytes) and fat cells (adipocytes) for its cellular utilisation. Such an activity of insulin brings down the level of glucose in the blood.
The posterior pituitary gland is not a ‘true’ endocrine gland because.
(a) it is provided with a duct
(b) it only stores and releases hormones
(c) it is under the regulation of hypothalamus
(d) it secretes enzymes
(b) The posterior pituitary gland is not a ‘true' endocrine gland because it only stores and releases two hormones-oxytocin and vasopressin, which are actually synthesised by the hypothalamus and are transported to the posterior pituitary through hypophyseal portal system.
Hence option (b) is correct.
Changes in GnRH pulse frequency in females is controlled by circulating levels of:-
(a) estrogen and inhibin
(b) progesterone only
(c) progesterone and inhibin
(d) estrogen and progesterone
(d) High levels of estrogen and progesterone give negative feedback to hypothalamus for the release of GnRH. Thus, inhibiting the gonadotropin release.
Which of the following pairs of hormones are not antagonistic (having opposite effects) to each other?
(a) Insulin Thyroid hormone
(b) Aldosterone Atrial Natriuretic Factor
(c) Relaxin Inhibin
(d) Parathormone Calcitonin
(c) Relaxin hormone which is secreted by posterior pituitary gland relaxes the pubic symphysis during parturition while inhibin decreases the secretion of FSH from anterior pituitary.
Which one of the following hormones is not involved in sugar metabolism?
Aldosterone is not involved in sugar metabolism. It is a steroid hormone (mineralocorticoid) produced by the outer section (zona glomerulosa) of the adrenal cortex in the adrenal gland. It plays a central role in the regulation of blood pressure mainly by acting on the distal tubules and collecting ducts of the nephron, increasing reabsorption of ions and water in the kidney, to cause the conservation of sodium, secretion of potassium, increase in water retention and decrease in blood pressure and blood volume.
Which one of the following hormones though synthesised elsewhere, is stored and released by the master gland?
(a) Antidiuretic hormone
(b) Luteinzing hormone
(d0 Melanocyte stimulating hormone
Antidiuretic Hormone (ADH) or vasopressin is a peptide hormone synthesised in the hypothalamus, but stored and released from posterior pituitary lobe.