.A hormone that has intracellular receptors would be
1. ACTH2. ADH
3. Melatonin
4. Aldosterone
.
Answer ▽ ✅Verified
4. Aldosterone
- Intracellular receptors are receptor proteins found on the inside of the cell, typically in the cytoplasm or nucleus. The ligand crosses the plasma membrane and binds to the receptor in the cytoplasm. The receptor then moves to the nucleus, where it binds DNA to regulate transcription.
- Steroid hormones are lipid-soluble and can easily pass through the cell membrane of a target cell into the cytoplasm. Thyroid hormone is a protein hormone that has a mechanism of action similar to that of steroid hormones, it can also pass through the plasma membrane of the cells and act on intracellular receptors. The hormones Aldosterone, Cortisol, Estradiol, and Progesterone are steroid hormones. These along with thyroid hormone act on intracellular receptors.
Aldosterone
The adrenal cortex can be divided into three layers, called zona
reticularis (inner layer), zona fasciculata (middle layer) and zona
glomerulosa (outer layer).
The adrenal cortex secretes many hormones,
commonly called as corticoids. The corticoids, which are involved in
carbohydrate metabolism are called glucocorticoids. In our body, cortisol
is the main glucocorticoid. Corticoids, which regulate the balance of water
and electrolytes in our body are called mineralocorticoids. Aldosterone is
the main mineralocorticoid in our body.
Aldosterone acts mainly at the renal
tubules and stimulates the reabsorption of Na+ and water and excretion
of K+ and phosphate ions. Thus, aldosterone helps in the maintenance of
electrolytes, body fluid volume, osmotic pressure and blood pressure.
The JGA plays a complex regulatory role. A fall in glomerular blood
flow/glomerular blood pressure/GFR can activate the JG cells to release
renin which converts angiotensinogen in blood to angiotensin I and
further to angiotensin II. Angiotensin II, being a powerful
vasoconstrictor, increases the glomerular blood pressure and thereby
GFR. Angiotensin II also activates the adrenal cortex to release
Aldosterone. Aldosterone causes reabsorption of Na+ and water from
the distal parts of the tubule. This also leads to an increase in blood
pressure and GFR. This complex mechanism is generally known as
the Renin-Angiotensin mechanism.
⬆️Prev____@organised notes_____Next⬇️
.Which of the following glands secretes the hormone melatonin?
1. anterior pituitary gland.
2. melanocytes.
3. pineal gland.
4. suprachiasmatic nucleus of hypothalamus
.
Answer ▽ ✅Verified
3. pineal gland.
The Pineal Gland
The pineal gland is located on the dorsal side of
forebrain. Pineal secretes a hormone called melatonin.
Melatonin plays a very important role in the regulation
of a 24-hour (diurnal) rhythm of our body. For
example, it helps in maintaining the normal rhythms
of sleep-wake cycle, body temperature. In addition,
melatonin also influences metabolism, pigmentation,
the menstrual cycle as well as our defense capability.
⬆️Prev____@organised notes_____Next⬇️
.
.How many hormones from the below list interact with intracellular receptors and regulate chromosome function and gene expression:-
GH, Oxytocin, ADH, ANF, Aldosterone, Cortisol, Thyroxin, Epinephrine, Estradiol, GnRH, and Progesterone.
A
Four
B
Five
C
Six
D
Seven
.
Answer ▽ ✅Verified
B
Five
- Intracellular receptors are receptor proteins found on the inside of the cell, typically in the cytoplasm or nucleus. The ligand crosses the plasma membrane and binds to the receptor in the cytoplasm. The receptor then moves to the nucleus, where it binds DNA to regulate transcription.
- Steroid hormones are lipid-soluble and can easily pass through the cell membrane of a target cell into the cytoplasm. Thyroid hormone is a protein hormone that has a mechanism of action similar to that of steroid hormones, it can also pass through the plasma membrane of the cells and act on intracellular receptors. The hormones Aldosterone, Cortisol, Estradiol, and Progesterone are steroid hormones. These along with thyroid hormone act on intracellular receptors.
⬆️Prev____@organised notes_____Next⬇️
.All the following are secreted by the anterior pituitary except:-
1. Prolactin
2. Somatotropin
3. Vasopressin
4. Gonadotropins
.
.
Answer ▽ ✅Verified
3. Vasopressin
The Pituitary Gland
The pituitary gland is located in a bony cavity
called sella tursica and is attached to
hypothalamus by a stalk .
It is
divided anatomically into an adenohypophysis
and a neurohypophysis.
Adenohypophysis
consists of two portions, pars distalis and pars
intermedia.
The pars distalis region of pituitary,
commonly called anterior pituitary, produces
growth hormone (GH), prolactin (PRL), thyroid
stimulating hormone (TSH),
adrenocorticotrophic hormone (ACTH),
luteinizing hormone (LH) and follicle
stimulating hormone (FSH).
Pars intermedia
secretes only one hormone called melanocyte
stimulating hormone (MSH). However, in
humans, the pars intermedia is almost merged
with pars distalis.
Neurohypophysis (pars
nervosa) also known as posterior pituitary, stores
and releases two hormones called oxytocin and
vasopressin, which are actually synthesised by
the hypothalamus and are transported axonally to neurohypophysis.
Over-secretion of GH stimulates abnormal growth of the body leading
to gigantism and low secretion of GH results in stunted growth resulting
in pituitary dwarfism. Excess secretion of growth hormone in adults
especially in middle age can result in severe disfigurement (especially of
the face) called Acromegaly, which may lead to serious complications,
and premature death if unchecked. The disease is hard to diagnose in
the early stages and often goes undetected for many years, until changes
in external features become noticeable.
Prolactin regulates the growth of
the mammary glands and formation of milk in them.
TSH stimulates the
synthesis and secretion of thyroid hormones from the thyroid gland.
ACTH
stimulates the synthesis and secretion of steroid hormones called
glucocorticoids from the adrenal cortex.
LH and FSH stimulate gonadal
activity and hence are called gonadotrophins. In males, LH stimulates
the synthesis and secretion of hormones called androgens from testis. In
males, FSH and androgens regulate spermatogenesis. In females, LH
induces ovulation of fully mature follicles (graafian follicles) and maintains
the corpus luteum, formed from the remnants of the graafian follicles
after ovulation. FSH stimulates growth and
development of the ovarian follicles in females.
MSH
acts on the melanocytes (melanin containing cells) and
regulates pigmentation of the skin.
Oxytocin acts on
the smooth muscles of our body and stimulates their
contraction. In females, it stimulates a vigorous
contraction of uterus at the time of child birth, and milk
ejection from the mammary gland.
Vasopressin acts
mainly at the kidney and stimulates resorption of water
and electrolytes by the distal tubules and thereby
reduces loss of water through urine (diuresis). Hence,
it is also called as anti-diuretic hormone (ADH).
An impairment affecting synthesis or release of ADH
results in a diminished ability of the kidney to conserve
water leading to water loss and dehydration. This
condition is known as Diabetes Insipidus.
⬆️Prev____@organised notes_____Next⬇️
.Identify the incorrect statement:
1. In males FSH regulates spermatogenesis
2. Thyroid gland produces T3 and thyroxine (T4) hormones
3. ACTH stimulates secretion of glucocorticoids
4. PTH is a hyperglycemic hormone
.
Answer ▽ ✅Verified
4. PTH is a hyperglycemic hormone
Parathyroid Gland
In humans, four parathyroid glands are present on the back side of the
thyroid gland, one pair each in the two lobes of the thyroid gland .
The parathyroid glands secrete a peptide hormone called
parathyroid hormone (PTH). The secretion of PTH is regulated by the
circulating levels of calcium ions.
Parathyroid hormone (PTH) increases the Ca2+ levels in the blood. PTH
acts on bones and stimulates the process of bone resorption (dissolution/
demineralisation). PTH also stimulates reabsorption of Ca2+ by the renal
tubules and increases Ca2+ absorption from the digested food. It is, thus,
clear that PTH is a hypercalcemic hormone, i.e., it increases the blood
Ca2+ levels. Along with TCT, it plays a significant role in calcium balance
in the body.
glucocorticoids from the adrenal cortex.
- Thyroid Gland
⬆️Prev____@organised notes_____Next⬇️
.Hormones that act by interacting with intracellular include all the following except:
1. Thyroxin
2. Estrogen
3. Epinephrine
4. Cortisol
.
Answer ▽ ✅Verified
3. Epinephrine
- Intracellular receptors are receptor proteins found on the inside of the cell, typically in the cytoplasm or nucleus. The ligand crosses the plasma membrane and binds to the receptor in the cytoplasm. The receptor then moves to the nucleus, where it binds DNA to regulate transcription.
- Steroid hormones are lipid-soluble and can easily pass through the cell membrane of a target cell into the cytoplasm. Thyroid hormone is a protein hormone that has a mechanism of action similar to that of steroid hormones, it can also pass through the plasma membrane of the cells and act on intracellular receptors. The hormones Aldosterone, Cortisol, Estrogen, and Progesterone are steroid hormones. These along with thyroid hormone act on intracellular receptors.
⬆️Prev____@organised notes_____Next⬇️
.
.The amino acid derivative among the following hormone is:-
1. Insulin
2. Epinephrine
3. Estradiol
4. Testosterone
.
Answer ▽ ✅Verified
2. Epinephrine
On the basis of their
chemical nature, hormones can be divided into groups :
(i) peptide, polypeptide, protein hormones (e.g., insulin, glucagon,
pituitary hormones, hypothalamic hormones, etc.)
(ii) steroids (e.g., cortisol, testosterone, estradiol and progesterone)
(iii) iodothyronines (thyroid hormones)
(iv) amino-acid derivatives (e.g., epinephrine).
The
adrenal gland is composed of the centrally located adrenal medulla and the outer
adrenal cortex. The adrenal medulla secretes epinephrine and norepinephrine.
These hormones increase alertness, pupilary dilation, piloerection, sweating, heart
beat, strength of heart contraction, rate of respiration, glycogenolysis, lipolysis,
proteolysis. The adrenal cortex secretes glucocorticoids and mineralocorticoids.
⬆️Prev____@organised notes_____Next⬇️
.Androgenic steroids in females are secreted by:
1. pineal gland
2. Testes
3. Adrenal cortex
4. Hypothalamus
.
.
Answer ▽ ✅Verified
3. Adrenal cortex
The adrenal cortex can be divided into three layers, called zona
reticularis (inner layer), zona fasciculata (middle layer) and zona
glomerulosa (outer layer). The adrenal cortex secretes many hormones,
commonly called as corticoids. The corticoids, which are involved in
carbohydrate metabolism are called glucocorticoids. In our body, cortisol
is the main glucocorticoid. Corticoids, which regulate the balance of water
and electrolytes in our body are called mineralocorticoids. Aldosterone is
the main mineralocorticoid in our body.
Glucocorticoids stimulate gluconeogenesis, lipolysis and proteolysis;
and inhibit cellular uptake and utilisation of amino acids. Cortisol is also
involved in maintaining the cardio-vascular system as well as the kidney
functions. Glucocorticoids, particularly cortisol, produces antiinflammatory
reactions and suppresses the immune response. Cortisol
stimulates the RBC production. Aldosterone acts mainly at the renal
tubules and stimulates the reabsorption of Na+ and water and excretion
of K+ and phosphate ions. Thus, aldosterone helps in the maintenance of
electrolytes, body fluid volume, osmotic pressure and blood pressure.
Small amounts of androgenic steroids are also secreted by the adrenal
cortex which play a role in the growth of axial hair, pubic hair and facial
hair during puberty.
⬆️Prev____@organised notes_____Next⬇️
.ACTH controls the secretion of:
1. cortisol
2. aldosterone
3. epinephrine
4 testosterone
.
.
Answer ▽ ✅Verified
1. cortisol
The Pituitary Gland
The pituitary gland is located in a bony cavity
called sella tursica and is attached to
hypothalamus by a stalk .
It is
divided anatomically into an adenohypophysis
and a neurohypophysis.
Adenohypophysis
consists of two portions, pars distalis and pars
intermedia.
The pars distalis region of pituitary,
commonly called anterior pituitary, produces
growth hormone (GH), prolactin (PRL), thyroid
stimulating hormone (TSH),
adrenocorticotrophic hormone (ACTH),
luteinizing hormone (LH) and follicle
stimulating hormone (FSH).
Pars intermedia
secretes only one hormone called melanocyte
stimulating hormone (MSH). However, in
humans, the pars intermedia is almost merged
with pars distalis.
Neurohypophysis (pars
nervosa) also known as posterior pituitary, stores
and releases two hormones called oxytocin and
vasopressin, which are actually synthesised by
the hypothalamus and are transported axonally to neurohypophysis.
Over-secretion of GH stimulates abnormal growth of the body leading
to gigantism and low secretion of GH results in stunted growth resulting
in pituitary dwarfism. Excess secretion of growth hormone in adults
especially in middle age can result in severe disfigurement (especially of
the face) called Acromegaly, which may lead to serious complications,
and premature death if unchecked. The disease is hard to diagnose in
the early stages and often goes undetected for many years, until changes
in external features become noticeable.
Prolactin regulates the growth of
the mammary glands and formation of milk in them.
TSH stimulates the
synthesis and secretion of thyroid hormones from the thyroid gland.
ACTH
stimulates the synthesis and secretion of steroid hormones called
glucocorticoids from the adrenal cortex.
LH and FSH stimulate gonadal
activity and hence are called gonadotrophins. In males, LH stimulates
the synthesis and secretion of hormones called androgens from testis. In
males, FSH and androgens regulate spermatogenesis. In females, LH
induces ovulation of fully mature follicles (graafian follicles) and maintains
the corpus luteum, formed from the remnants of the graafian follicles
after ovulation. FSH stimulates growth and
development of the ovarian follicles in females.
MSH
acts on the melanocytes (melanin containing cells) and
regulates pigmentation of the skin.
Oxytocin acts on
the smooth muscles of our body and stimulates their
contraction. In females, it stimulates a vigorous
contraction of uterus at the time of child birth, and milk
ejection from the mammary gland.
Vasopressin acts
mainly at the kidney and stimulates resorption of water
and electrolytes by the distal tubules and thereby
reduces loss of water through urine (diuresis). Hence,
it is also called as anti-diuretic hormone (ADH).
An impairment affecting synthesis or release of ADH
results in a diminished ability of the kidney to conserve
water leading to water loss and dehydration. This
condition is known as Diabetes Insipidus.
⬆️Prev____@organised notes_____Next⬇️
.Name a peptide hormone which acts mainly on hepatocytes, adipocytes and enhances cellular glucose uptake and utilisation.
1. Insulin
2. Glucagon
3. Secretin
4. Gastrin
.
.
Answer ▽ ✅Verified
1. Insulin
Pancreas
Pancreas is a composite gland which acts as both exocrine
and endocrine gland.
The endocrine pancreas consists of ‘Islets of
Langerhans’. There are about 1 to 2 million Islets of Langerhans in a
normal human pancreas representing only 1 to 2 per cent of the pancreatic
tissue.
The two main types of cells in the Islet of Langerhans are called
a-cells and b-cells. The a-cells secrete a hormone called glucagon, while
the b-cells secrete insulin.
Glucagon is a peptide hormone, and plays an important role in
maintaining the normal blood glucose levels. Glucagon acts mainly on
the liver cells (hepatocytes) and stimulates glycogenolysis resulting in an
increased blood sugar (hyperglycemia). In addition, this hormone
stimulates the process of gluconeogenesis which also contributes to
hyperglycemia. Glucagon reduces the cellular glucose uptake and
utilisation. Thus, glucagon is a hyperglycemic hormone.
Insulin is a peptide hormone, which plays a major role in the
regulation of glucose homeostasis. Insulin acts mainly on hepatocytes
and adipocytes (cells of adipose tissue), and enhances cellular glucose
uptake and utilisation. As a result, there is a rapid movement of glucose
from blood to hepatocytes and adipocytes resulting in decreased blood
glucose levels (hypoglycemia). Insulin also stimulates conversion of
glucose to glycogen (glycogenesis) in the target cells. The glucose
homeostasis in blood is thus maintained jointly by the two – insulin and
glucagons.
Prolonged hyperglycemia leads to a complex disorder called diabetes
mellitus which is associated with loss of glucose through urine and
formation of harmful compounds known as ketone bodies. Diabetic
patients are successfully treated with insulin therapy.
⬆️Prev____@organised notes_____Next⬇️
.Which one of the following hormones though synthesised elsewhere, is stored and
released by the master gland?
1. Antidiuretic hormone
2. Luteinzing hormone
3. Prolactin
4. Melanocyte stimulating hormone
.
.
Answer ▽ ✅Verified
1. Antidiuretic hormone
The Pituitary Gland
The pituitary gland is located in a bony cavity
called sella tursica and is attached to
hypothalamus by a stalk .
It is
divided anatomically into an adenohypophysis
and a neurohypophysis.
Adenohypophysis
consists of two portions, pars distalis and pars
intermedia.
The pars distalis region of pituitary,
commonly called anterior pituitary, produces
growth hormone (GH), prolactin (PRL), thyroid
stimulating hormone (TSH),
adrenocorticotrophic hormone (ACTH),
luteinizing hormone (LH) and follicle
stimulating hormone (FSH).
Pars intermedia
secretes only one hormone called melanocyte
stimulating hormone (MSH). However, in
humans, the pars intermedia is almost merged
with pars distalis.
Neurohypophysis (pars
nervosa) also known as posterior pituitary, stores
and releases two hormones called oxytocin and
vasopressin, which are actually synthesised by
the hypothalamus and are transported axonally to neurohypophysis.
Over-secretion of GH stimulates abnormal growth of the body leading
to gigantism and low secretion of GH results in stunted growth resulting
in pituitary dwarfism. Excess secretion of growth hormone in adults
especially in middle age can result in severe disfigurement (especially of
the face) called Acromegaly, which may lead to serious complications,
and premature death if unchecked. The disease is hard to diagnose in
the early stages and often goes undetected for many years, until changes
in external features become noticeable.
Prolactin regulates the growth of
the mammary glands and formation of milk in them.
TSH stimulates the
synthesis and secretion of thyroid hormones from the thyroid gland.
ACTH
stimulates the synthesis and secretion of steroid hormones called
glucocorticoids from the adrenal cortex.
LH and FSH stimulate gonadal
activity and hence are called gonadotrophins. In males, LH stimulates
the synthesis and secretion of hormones called androgens from testis. In
males, FSH and androgens regulate spermatogenesis. In females, LH
induces ovulation of fully mature follicles (graafian follicles) and maintains
the corpus luteum, formed from the remnants of the graafian follicles
after ovulation. FSH stimulates growth and
development of the ovarian follicles in females.
MSH
acts on the melanocytes (melanin containing cells) and
regulates pigmentation of the skin.
Oxytocin acts on
the smooth muscles of our body and stimulates their
contraction. In females, it stimulates a vigorous
contraction of uterus at the time of child birth, and milk
ejection from the mammary gland.
Vasopressin acts
mainly at the kidney and stimulates resorption of water
and electrolytes by the distal tubules and thereby
reduces loss of water through urine (diuresis). Hence,
it is also called as anti-diuretic hormone (ADH).
An impairment affecting synthesis or release of ADH
results in a diminished ability of the kidney to conserve
water leading to water loss and dehydration. This
condition is known as Diabetes Insipidus.
⬆️Prev____@organised notes_____Next⬇️
.Identify the hormone with its correct matching of source and function.
1. Oxytocin-posterior pituitary, growth and maintenance of mammary glands
2. Melatonin-pineal gland, regulates the normal rhythm of sleepwake cycle
3. Progesterone-corpus luteum, stimulation of growth and activities of female secondary sex organs
4. Atrial natriuretic factor-ventricular wall increases the blood pressure
.
.
Answer ▽ ✅Verified
2. Melatonin-pineal gland, regulates the normal rhythm of sleepwake cycle
Hormones are the small molecules of low molecular weight and they act as an intercellular messenger.
> Oxytocin- this hormone is released by the posterior pituitary. Oxytocin is also called as milk ejection hormone as it ejects milk from mammary glands during suckling. It is also called birth hormone as it causes labor pain/ uterine contraction for the delivery of the baby.
> Melatonin- this hormone is released by the pineal gland. It works as a biological clock and is involved in the regulation of daily or sleep-wake cycles called a circadian cycle.
> Progesterone- this hormone is released by the corpus luteum. It is called a pregnancy hormone as it governs the changes during pregnancy. It is a type of steroid hormone.
> Atrial natriuretic factor- this hormone dilates the blood vessels and decreases blood pressure. An increase in blood flow to the heart atria stimulates the release of the atrial natriuretic hormone.
⬆️Prev____@organised notes_____Next⬇️
.A pregnant female delivers a baby, who suffers from stunted growth mental retardation low intelligence quotient and abnormal skin. This is the result of
1. deficiency of iodine in diet
2. low secretion of growth hormone
3. cancer of the thyroid gland
4. over secretion of pars distalis
.
.
Answer ▽ ✅Verified
1. deficiency of iodine in diet
Thyroid Gland
The thyroid gland is composed of two lobes which are
located on either side of the trachea (Figure 22.3). Both
the lobes are interconnected with a thin flap of connective
tissue called isthmus. The thyroid gland is composed of
follicles and stromal tissues. Each thyroid follicle is
composed of follicular cells, enclosing a cavity. These
follicular cells synthesise two hormones,
tetraiodothyronine or thyroxine (T4) and
triiodothyronine (T3). Iodine is essential for the normal
rate of hormone synthesis in the thyroid. Deficiency of
iodine in our diet results in hypothyroidism and
enlargement of the thyroid gland, commonly called
goitre. Hypothyroidism during pregnancy causes
defective development and maturation of the growing
baby leading to stunted growth (cretinism), mental retardation, low
intelligence quotient, abnormal skin, deaf-mutism, etc. In adult women,
hypothyroidism may cause menstrual cycle to become irregular. Due to
cancer of the thyroid gland or due to development of nodules of the thyroid
glands, the rate of synthesis and secretion of the thyroid hormones is
increased to abnormal high levels leading to a condition called
hyperthyroidism which adversely affects the body physiology.
Exopthalmic goitre is a form of hyperthyroidism, characterised by
enlargement of the thyroid gland, protrusion of the eyeballs, increased
basal metabolic rate, and weight loss, also called Graves’ disease.
Thyroid hormones play an important role in the regulation of the basal
metabolic rate. These hormones also support the process of red blood cell
formation. Thyroid hormones control the metabolism of carbohydrates, proteins
and fats. Maintenance of water and electrolyte balance is also influenced by
thyroid hormones. Thyroid gland also secretes a protein hormone called
thyrocalcitonin (TCT) which regulates the blood calcium levels.
⬆️Prev____@organised notes_____Next⬇️
.Which of the following statement is correct in relation to the endocrine system?
1. Adenohypophysis is under direct neural regulation of the hypothalamus
2. Organs in the body like gastrointestinal tract. heart, kidney and liver do not produce any hormones
3. Non-nutrient chemicals produced by the body in trace amount that act as intercellular messenger are known as hormones
4. Releasing and inhibitory hormones are produced by the pituitary gland
.
.
Answer ▽ ✅Verified
3. Non-nutrient chemicals produced by the body in trace amount that act as intercellular messenger are known as hormones
Hormones are chemicals that have no nutritional value and their only function is to act as messengers between different organs of the body so that coordination is maintained in the body of an organism. Hormones are secreted from various glands of the body known as endocrine glands. They are produced in trace amounts and released directly into the blood through which they are transported to their target organs.
Improper functioning of the endocrine glands results in over or underproduction of hormones which lead to various hormonal disorders in the body.
Let us now study the corrected versions of the other statements given in the options.
-Adenohypophysis (anterior pituitary) is under the indirect regulation of the hypothalamus through the portal system. Neurohypophysis (posterior pituitary) is under direct regulation.
-Organs in the body like the gastrointestinal tract produces 4 major peptide hormones known as gastrin, secretin, CCK, and GIP, the heart produces atrial natriuretic factor (ANF), the kidney produces erythropoietin and the liver produces angiotensinogen.
-Releasing and inhibitory hormones are produced by the hypothalamus by which it controls the pituitary gland.
So, the correct option is ‘Non-nutrient chemicals produced by the body in trace amounts that act as intercellular messengers are known as hormones.’
Note: -CCK is cholecystokinin and GIP is a gastric inhibitory peptide.
-ANF is released from the atrial wall of the heart and causes vasodilation to reduce the blood pressure.
-Erythropoietin released from the juxtaglomerular cells of the kidney stimulates erythropoiesis i.e. formation of RBC.
⬆️Prev____@organised notes_____Next⬇️
.Which one of the following pairs of hormones are the examples of those that can easily
pass through the cell membrane of the target cell and bind to a receptor inside it (mostly in the nucleus)?
1. Insulin and glucagon
2. Thyroxin and insulin
3. Somatostatin and oxytocin
4. Cortisol and testosterone
.
.
Answer ▽ ✅Verified
4. Cortisol and testosterone
On the basis of their
chemical nature, hormones can be divided into groups :
(i) peptide, polypeptide, protein hormones (e.g., insulin, glucagon,
pituitary hormones, hypothalamic hormones, etc.)
(ii) steroids (e.g., cortisol, testosterone, estradiol and progesterone)
(iii) iodothyronines (thyroid hormones)
(iv) amino-acid derivatives (e.g., epinephrine).
- As it has been mentioned in the question of these hormones, it binds to the receptor mostly in the nucleus of the target cell after across the cell membrane. At first, steroid hormone (cortisol and testosterone) binds to an intracellular receptor protein in the cytoplasm and forms a hormone-receptor complex then this complex is transported into the nucleus.
- Generally, a specific hormone is used to bind with the specific plasma receptor protein—for example, cortisol bound with corticosteroid-binding globulin (CBG) which is present in the blood.
- Moreover, this pair of hormones “cortisol and testosterone” have numerous therapeutic uses as well as regulate a wide range of developmental and physiological activities from fetal life to adulthood. Cortisol and testosterone are examples of those hormones that can easily pass through the cell membrane of the target cell and bind to the receptor inside it (mostly in the nucleus).
⬆️Prev____@organised notes_____Next⬇️
.Injury to adrenal cortex is not likely to affect the secretion of which one of the following ?
1. Aldosterone
2. Both androstenedione and dehydroepiandrosterone
3. Adrenalin
4. Cortisol
.
.
Answer ▽ ✅Verified
3. Adrenalin
Adrenal Gland
Our body has one pair of adrenal glands, one at the anterior part of each
kidney .
The gland is composed of two types of tissues.
The centrally located tissue is called the adrenal medulla, and outside
this lies the adrenal cortex .
Underproduction of hormones by the adrenal cortex alters
carbohydrate metabolism causing acute weakness and fatigue leading
to a disease called Addison’s disease.
The adrenal medulla secretes two hormones called adrenaline or
epinephrine and noradrenaline or norepinephrine. These are
commonly called as catecholamines. Adrenaline and noradrenaline are
rapidly secreted in response to stress of any kind and during emergency
situations and are called emergency hormones or hormones of Fight
or Flight. These hormones increase alertness, pupilary dilation,
piloerection (raising of hairs), sweating etc. Both the hormones increase
the heart beat, the strength of heart contraction and the rate of respiration.
Catecholamines also stimulate the breakdown of glycogen resulting in
an increased concentration of glucose in blood. In addition, they also
stimulate the breakdown of lipids and proteins.
The adrenal cortex can be divided into three layers, called zona
reticularis (inner layer), zona fasciculata (middle layer) and zona
glomerulosa (outer layer). The adrenal cortex secretes many hormones,
commonly called as corticoids. The corticoids, which are involved in
carbohydrate metabolism are called glucocorticoids. In our body, cortisol
is the main glucocorticoid. Corticoids, which regulate the balance of water
and electrolytes in our body are called mineralocorticoids. Aldosterone is
the main mineralocorticoid in our body.
Glucocorticoids stimulate gluconeogenesis, lipolysis and proteolysis;
and inhibit cellular uptake and utilisation of amino acids. Cortisol is also
involved in maintaining the cardio-vascular system as well as the kidney
functions. Glucocorticoids, particularly cortisol, produces antiinflammatory
reactions and suppresses the immune response. Cortisol
stimulates the RBC production. Aldosterone acts mainly at the renal
tubules and stimulates the reabsorption of Na+ and water and excretion
of K+ and phosphate ions. Thus, aldosterone helps in the maintenance of
electrolytes, body fluid volume, osmotic pressure and blood pressure.
Small amounts of androgenic steroids are also secreted by the adrenal
cortex which play a role in the growth of axial hair, pubic hair and facial
hair during puberty.
⬆️Prev____@organised notes_____Next⬇️
.The blood calcium level is lowered by the deficiency of ?
1. parathormone
2. thyroxine
3. calcitonin
4. Both 1. and 2.
.
.
Answer ▽ ✅Verified
1. parathormone
Parathyroid Gland
In humans, four parathyroid glands are present on the back side of the
thyroid gland, one pair each in the two lobes of the thyroid gland (Figure
22.3b). The parathyroid glands secrete a peptide hormone called
parathyroid hormone (PTH). The secretion of PTH is regulated by the
circulating levels of calcium ions.
Parathyroid hormone (PTH) increases the Ca2+ levels in the blood. PTH
acts on bones and stimulates the process of bone resorption (dissolution/
demineralisation). PTH also stimulates reabsorption of Ca2+ by the renal
tubules and increases Ca2+ absorption from the digested food. It is, thus,
clear that PTH is a hypercalcemic hormone, i.e., it increases the blood
Ca2+ levels. Along with TCT, it plays a significant role in calcium balance
in the body.
Thyroid gland secretes a protein hormone called
thyrocalcitonin (TCT) which regulates the blood calcium levels by lowering
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.Study the given figure showing various human endocrine glands. Select the correct
statement(s) regarding these.
(i) Gland P is stimulated to secrete its hormones by thyrotropin secreted by anterior lobe of pituitary gland.
(ii) Gland R is associated with the secretion of hormones corticosteroids, epinephrine and norepinephrine.
(iii) Glands T and U represent the sex glands, which are derived from the mesoderm of embryo.
(iv) Gland Q is derived from mesoderm of the embryo and its increased size results in ageing.
(v) Gland S secretes the hormone glucagon which stimulates the lever to convert glucose into glycogen.
1. (i) and (ii)
2. (ii) and (iv)
3. (i), (ii) and (iii)
4. All are correct
.
.
Answer ▽ ✅Verified
3. (i), (ii) and (iii) is correct.
(iv)Gland Q is derived from mesoderm of the embryo and its decrease size results in ageing.
(v) Gland S secretes the hormone insulin which stimulates the lever to convert glucose into glycogen.
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.Sella Turcica is found
1. in bones
2. in joints
3. nearby pituitary
4. nearby thyroid
.
.
Answer ▽ ✅Verified
1. in bones
The pituitary gland is located in a bony cavity
called sella tursica and is attached to
hypothalamus by a stalk .
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.Which one of the following four glands is correctly matched with the accompanying description?
1. Thyroid - hyperactivity in young children causes cretinism
2. Thymus - starts undergoing atrophy after puberty
3. Parathyroid - secrets parathormone which promotes movement of calcium ions from blood into bones during calcification
4. Pancreas - Delta cells of the Islets of Langerhans secrete a hormone which stimulates glycolysis in liver
.
.
Answer ▽ ✅Verified
2. Thymus - starts undergoing atrophy after puberty
Thymus
The thymus gland is a lobular structure located between lungs behind
sternum on the ventral side of aorta. The thymus plays a major role in
the development of the immune system. This gland secretes the peptide
hormones called thymosins. Thymosins play a major role in the
differentiation of T-lymphocytes, which provide cell-mediated
immunity. In addition, thymosins also promote production of antibodies
to provide humoral immunity. Thymus is degenerated in old individuals
resulting in a decreased production of thymosins. As a result, the immune
responses of old persons become weak.
Options-
1. Thyroid - hyperactivity in young children causes giganitism.
2. Thymus - starts undergoing atrophy after puberty
3. Parathyroid - secrets parathormone which promotes movement of calcium ions from bones to blood during decalcification.
4. Pancreas - Delta cells of the Islets of Langerhans secrete a hormone-insulin which downgrade glycolysis in liver
.
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.Which of the following hormone regulates the growth of mammary glands and formation of milk in them.
1. Prolactin
2. Oxytocin
3. FSH
4. LH
.
.
Answer ▽ ✅Verified
1. Prolactin
Prolactin regulates the growth of
the mammary glands and formation of milk in them.
Oxytocin acts on
the smooth muscles of our body and stimulates their
contraction. In females, it stimulates a vigorous
contraction of uterus at the time of child birth, and milk
ejection from the mammary gland.
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.Which of the following hormone acts on the smooth muscles of our body and regulates its contraction?
1. vasopressin
2. Oxytocin
3. Gonadotrophins
4. Gulcocorticoids
.
.
Answer ▽ ✅Verified
2. Oxytocin
Oxytocin acts on
the smooth muscles of our body and stimulates their
contraction. In females, it stimulates a vigorous
contraction of uterus at the time of child birth, and milk
ejection from the mammary gland.
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.Which of the following is true about melatonin?
(1) It influences metabolism
(2) It influences pigmentation
(3) It influences menstrual cycle
(4) All of these
.
.
Answer ▽ ✅Verified
(4) All of these
The pineal gland is located on the dorsal side of
forebrain. Pineal secretes a hormone called melatonin.
Melatonin plays a very important role in the regulation
of a 24-hour (diurnal) rhythm of our body. For
example, it helps in maintaining the normal rhythms
of sleep-wake cycle, body temperature. In addition,
melatonin also influences metabolism, pigmentation,
the menstrual cycle as well as our defense capability.
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.The thyroid gland is composed of
(1) Follicles
(2) Stromal tissues
(3) Follicular cells enclosing a cavity
(4) All of these
.
.
Answer ▽ ✅Verified
(4) All of these
The thyroid gland is composed of
follicles and stromal tissues. Each thyroid follicle is
composed of follicular cells, enclosing a cavity. These
follicular cells synthesise two hormones,
tetraiodothyronine or thyroxine (T4) and
triiodothyronine (T3). I
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.A person who has enlarged thyroid gland, protruded eye balls, increased BMR and weight loss is suffering from
(1) Exopthalmic goitre
(2) Graves’ disease
(3) Both 1 and 2
(4) Addison disease
.
.
Answer ▽ ✅Verified
(3) Both 1 and 2
Exopthalmic goitre is a form of hyperthyroidism, characterised by
enlargement of the thyroid gland, protrusion of the eyeballs, increased
basal metabolic rate, and weight loss, also called Graves’ disease.
Underproduction of hormones by the adrenal cortex alters
carbohydrate metabolism causing acute weakness and fatigue leading
to a disease called Addison’s disease.
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.Which of the following hormone regulates BMR of the body?
(1) Thyroxine
(2) Thyrocalcitonin
(3) Adrenaline
(4) Both 2. and 3.
.
.
Answer ▽ ✅Verified
(1) Thyroxine
Thyroid hormones play an important role in the regulation of the basal
metabolic rate. These hormones also support the process of red blood cell
formation. Thyroid hormones control the metabolism of carbohydrates, proteins
and fats. Maintenance of water and electrolyte balance is also influenced by
thyroid hormones.
Thyroid gland also secretes a protein hormone called
thyrocalcitonin (TCT) which regulates the blood calcium levels.
The adrenal medulla secretes two hormones called adrenaline or
epinephrine and noradrenaline or norepinephrine. These are
commonly called as catecholamines. Adrenaline and noradrenaline are
rapidly secreted in response to stress of any kind and during emergency
situations and are called emergency hormones or hormones of Fight
or Flight. These hormones increase alertness, pupilary dilation,
piloerection (raising of hairs), sweating etc. Both the hormones increase
the heart beat, the strength of heart contraction and the rate of respiration.
Catecholamines also stimulate the breakdown of glycogen
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.Thyroxine controls the metabolism of the following Macromolecules except
(1) Carbohydrates
(2) Fats
(3) Proteins
(4) Nucleic acids
.
.
Answer ▽ ✅Verified
(4) Nucleic acids
Thyroid hormones play an important role in the regulation of the basal
metabolic rate. These hormones also support the process of red blood cell
formation. Thyroid hormones control the metabolism of carbohydrates, proteins
and fats. Maintenance of water and electrolyte balance is also influenced by
thyroid hormones. Thyroid gland also secretes a protein hormone called
thyrocalcitonin (TCT) which regulates the blood calcium levels.
⬆️Prev____@organised notes_____Next⬇️
.Which hormone regulates the calcium level in our body?
(1) Thyrocalcitonin
(2) Parathyroid hormone
(3) Thyroxine
(4) Both 1 and 2
.
.
Answer ▽ ✅Verified
(4) Both 1 and 2
Thyroid gland also secretes a protein hormone called
thyrocalcitonin (TCT) which regulates the blood calcium levels.
Parathyroid Gland
In humans, four parathyroid glands are present on the back side of the
thyroid gland, one pair each in the two lobes of the thyroid gland .
The parathyroid glands secrete a peptide hormone called
parathyroid hormone (PTH). The secretion of PTH is regulated by the
circulating levels of calcium ions.
Parathyroid hormone (PTH) increases the Ca2+ levels in the blood. PTH
acts on bones and stimulates the process of bone resorption (dissolution/
demineralisation). PTH also stimulates reabsorption of Ca2+ by the renal
tubules and increases Ca2+ absorption from the digested food. It is, thus,
clear that PTH is a hypercalcemic hormone, i.e., it increases the blood
Ca2+ levels. Along with TCT, it plays a significant role in calcium balance
in the body.
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.Which of the following hormone is responsible for cell mediated immunity?
(1) Thyroxine
(2) adrenaline
(3) Thymosins
(4) parathyroid
.
.
Answer ▽ ✅Verified
(3) Thymosins
Thymus
The thymus gland is a lobular structure located between lungs behind
sternum on the ventral side of aorta. The thymus plays a major role in
the development of the immune system. This gland secretes the peptide
hormones called thymosins. Thymosins play a major role in the
differentiation of T-lymphocytes, which provide cell-mediated
immunity. In addition, thymosins also promote production of antibodies
to provide humoral immunity. Thymus is degenerated in old individuals
resulting in a decreased production of thymosins. As a result, the immune
responses of old persons become weak.
⬆️Prev____@organised notes_____Next⬇️
.Which of the following hormone is responsible for humoral immunity?
(1) Thyroxine
(2) Antibodies
(3) Thymosins
(4) parathyroid
.
.
Answer ▽ ✅Verified
(3) Thymosins
Thymus
The thymus gland is a lobular structure located between lungs behind
sternum on the ventral side of aorta. The thymus plays a major role in
the development of the immune system. This gland secretes the peptide
hormones called thymosins. Thymosins play a major role in the
differentiation of T-lymphocytes, which provide cell-mediated
immunity. In addition, thymosins also promote production of antibodies
to provide humoral immunity. Thymus is degenerated in old individuals
resulting in a decreased production of thymosins. As a result, the immune
responses of old persons become weak.
⬆️Prev____@organised notes_____Next⬇️
.Which of the following is incorrect about thymus gland
(1) lobular in structure
(2) located on ventral side of heart and aorta
(3) important for development of immune system
(4) It degenerates in old ages
.
.
Answer ▽ ✅Verified
(2) located on ventral side of heart and aorta
Thymus
The thymus gland is a lobular structure located between lungs behind
sternum on the ventral side of aorta. The thymus plays a major role in
the development of the immune system. This gland secretes the peptide
hormones called thymosins. Thymosins play a major role in the
differentiation of T-lymphocytes, which provide cell-mediated
immunity. In addition, thymosins also promote production of antibodies
to provide humoral immunity. Thymus is degenerated in old individuals
resulting in a decreased production of thymosins. As a result, the immune
responses of old persons become weak.
⬆️Prev____@organised notes_____End⬇️
