The Pituitary Gland Questions in English

(D) $Sella$ $turcica$,also known as the 'Turkish saddle',is a saddle-shaped depression located in the sphenoid bone at the base of the mammalian skull.
This depression serves as the housing for the pituitary gland (hypophysis).

(D) The posterior pituitary (neurohypophysis) does not synthesize hormones itself.
It stores and releases two hormones,$Oxytocin$ and $Vasopressin$ $(ADH)$,which are synthesized by the neurosecretory cells of the hypothalamus.
These hormones are transported along the axons of these neurons to the posterior pituitary,where they are stored and released into the blood under the control of neurosecretory nerve axons.

(D) The deficiency of Somatotrophic Hormone $(STH)$,also known as Growth Hormone $(GH)$,during early childhood leads to the premature cessation of long bone growth and overall body development. This condition is clinically known as Dwarfism.

(A) Growth hormone,also known as $STH$ (Somatotropic Hormone),is produced in the anterior lobe of the pituitary gland.
It stimulates the growth and development of all body tissues by accelerating protein synthesis and cell division.

(A) The hormones secreted by the pituitary gland are either proteins (peptides) or glycoproteins.
For example,Growth Hormone $(GH)$,Prolactin $(PRL)$,and Adrenocorticotropic Hormone $(ACTH)$ are peptide hormones,while Thyroid Stimulating Hormone $(TSH)$,Luteinizing Hormone $(LH)$,and Follicle Stimulating Hormone $(FSH)$ are glycoprotein hormones.
Therefore,they are all proteinaceous in nature.

(C) $ADH$ (Antidiuretic Hormone),also known as vasopressin,is synthesized by the hypothalamus and stored and released by the posterior pituitary gland (neurohypophysis).
Its primary function is to regulate water balance in the body by promoting water reabsorption in the distal convoluted tubules and collecting ducts of the nephrons.
$A$ deficiency of $ADH$ leads to a condition known as Diabetes insipidus,characterized by excessive thirst and the excretion of large volumes of dilute urine.

(A) The hyposecretion of Growth Hormone $(GH)$ or Somatotropic Hormone $(STH)$ from the anterior pituitary gland during the growth years results in dwarfism or midgets. This condition is characterized by stunted physical growth.

(B) The posterior lobe of the pituitary,also known as the $Neurohypophysis$,is composed of non-myelinated nerve fibers and pituicytes (specialized glial cells). It does not synthesize hormones itself but stores and releases two hormones,$Oxytocin$ and $Vasopressin$ $(ADH)$,which are synthesized by the hypothalamus. Therefore,it is neural in origin and structure.

(A) The posterior pituitary (neurohypophysis) stores and releases two hormones: oxytocin and vasopressin.
Vasopressin is also known as Antidiuretic hormone $(ADH)$ because it acts on the kidneys to stimulate the reabsorption of water and electrolytes,thereby reducing the loss of water through urine (diuresis).
Therefore,the correct answer is $A$.

(D) The pituitary gland is anatomically and embryologically divided into two main parts:
$1$. $Adenohypophysis$: This is the anterior lobe of the pituitary gland.
$2$. $Neurohypophysis$: This is the posterior lobe of the pituitary gland.
Therefore,the other name for the anterior pituitary is $Adenohypophysis$.

(B) The neurohypophysis (posterior pituitary) does not synthesize hormones itself but stores and releases two hormones produced by the hypothalamus:
$1$. Antidiuretic hormone $(ADH)$,also known as vasopressin or pitressin.
$2$. Oxytocin,also known as pitocin.
Therefore,the neurohypophysis releases $ADH$ and oxytocin.

(C) The correct answer is $C$.
Acromegaly is caused by the hypersecretion of Growth Hormone $(GH)$ in adults after adolescence.
Due to the closure of epiphyseal plates,the person does not grow in height,but the bones of the hands,feet,nose,and lower jaw become abnormally enlarged and thickened.
This condition leads to a characteristic facial appearance and is known as Acromegaly.

(C) $Vasopressin$, also known as $Antidiuretic$ $Hormone$ $(ADH)$, is secreted by the posterior pituitary gland.
Its primary function is to stimulate the reabsorption of water and electrolytes by the distal tubules of the kidney, thereby reducing water loss through urine.
$A$ deficiency of $Vasopressin$ leads to the inability of the kidneys to conserve water, resulting in the excretion of a large volume of dilute urine. This condition is known as $Diabetes$ $insipidus$.

(C) The pituitary gland is divided into two main parts: the anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis).
The posterior lobe,or neurohypophysis,stores and releases two hormones,oxytocin and vasopressin $(ADH)$,which are synthesized by the hypothalamus.
Therefore,the correct term for the posterior lobe is neurohypophysis.

(B) The correct answer is $B$.
Hypersecretion of growth hormone $(GH)$ from the pituitary gland during childhood leads to Gigantism.
This condition is characterized by abnormal growth of the body,resulting in excessive height and very long bones.

(C) The activity of the adrenal cortex is regulated by the Adrenocorticotropic Hormone $(ACTH)$.
$ACTH$ is secreted by the anterior pituitary gland.
It stimulates the adrenal cortex to synthesize and secrete glucocorticoids,which are steroid hormones involved in glucose metabolism and stress response.
Therefore,the correct abbreviation is $ACTH$.

(A) Adrenocorticotropic hormone $(ACTH)$,also known as corticotropin,is secreted by the anterior lobe of the pituitary gland (adenohypophysis).
It stimulates the synthesis and secretion of steroid hormones called glucocorticoids from the adrenal cortex.

(C) The intermediate lobe of the pituitary gland,also known as the pars intermedia,secretes Melanocyte Stimulating Hormone $(MSH)$.
$MSH$ acts on melanocytes (melanin-containing cells) and regulates skin pigmentation.
In many fishes,amphibians,and reptiles,$MSH$ stimulates the dispersion of melanin granules within melanocytes,which results in the darkening of the skin.

(A) The correct answer is $MSH$ (Melanocyte Stimulating Hormone).
$MSH$ is considered a direct action hormone because it acts directly on the target cells,specifically the melanocytes or chromatophores in the skin.
It regulates the distribution and dispersion of melanin granules within these cells,thereby influencing skin pigmentation.
In contrast,hormones like $ACTH$,$TSH$,and $ICSH$ are tropic hormones,meaning they stimulate other endocrine glands to secrete their respective hormones.

(D) The posterior lobe of the pituitary gland,also known as the $Neurohypophysis$,stores and releases two hormones: $Oxytocin$ and $Vasopressin$ (or $Antidiuretic$ $Hormone$ - $ADH$).
$Oxytocin$ acts on the smooth muscles of our body and stimulates their contraction.
In females,it stimulates a vigorous contraction of the uterus at the time of childbirth (parturition) and milk ejection from the mammary glands.
Therefore,the hormone released by the posterior pituitary is concerned with the contraction of the uterus.

(D) The anterior lobe of the pituitary gland,also known as the adenohypophysis,secretes several hormones that regulate metabolism.
$1$. Growth Hormone $(GH)$ stimulates protein synthesis and promotes the utilization of fats for energy.
$2$. Adrenocorticotropic Hormone $(ACTH)$ and Thyroid Stimulating Hormone $(TSH)$ indirectly influence carbohydrate and lipid metabolism by regulating the secretion of other endocrine glands.
$3$. Therefore,the anterior pituitary plays a significant role in the regulation of protein,fat,and carbohydrate metabolism.

(D) The complete failure or hyposecretion of the hormones of the adenohypophysis (anterior pituitary) in adults leads to a condition known as Simmond's disease (also called panhypopituitarism).
This condition is characterized by extreme weight loss,cachexia,loss of secondary sexual characteristics,and signs of premature aging.

(B) The $Pituitary$ gland is also known as the $Hypophysis$ cerebri.
It is often referred to as the 'master gland' because it regulates many vital body activities and controls the secretion of other endocrine glands.
Therefore,the correct option is $B$.

(A) The pituitary gland is a small,pea-sized endocrine gland located at the base of the brain.
It is situated in a bony cavity called the $sella$ $turcica$ and is attached to the hypothalamus by a stalk called the infundibulum.
Therefore,the correct location is the brain.

(D) Acromegaly is a condition caused by the hypersecretion of growth hormone $(GH)$ from the anterior lobe of the pituitary gland in adults. This leads to the abnormal growth of bones,particularly in the face,hands,and feet.

(B) $FSH$ stands for Follicle Stimulating Hormone.
It is a gonadotropin secreted by the anterior pituitary gland.
Chemically,$FSH$ is a glycoprotein,which consists of a protein chain with carbohydrate side chains attached to it.

(D) The pituitary gland is anatomically divided into an adenohypophysis and a neurohypophysis.
$1$. The adenohypophysis consists of two portions: $Pars \text{ distalis}$ and $Pars \text{ intermedia}$.
$2$. The neurohypophysis is also known as $Pars \text{ nervosa}$ (or posterior pituitary).
Therefore, the pituitary gland is composed of $Pars \text{ distalis}$, $Pars \text{ intermedia}$, and $Pars \text{ nervosa}$.

(C) Gonadotrophic hormones,specifically $FSH$ (Follicle Stimulating Hormone) and $LH$ (Luteinizing Hormone),are produced and secreted by the anterior lobe of the pituitary gland,which is known as the $adenohypophysis$.
These hormones play a crucial role in regulating the reproductive functions of the gonads (testes and ovaries).

(B) The Adrenocorticotropic Hormone $(ACTH)$ is secreted by the anterior pituitary gland.
It acts on the adrenal cortex to stimulate the synthesis and secretion of steroid hormones,specifically glucocorticoids like cortisol.
$FSH$ and $LH$ are gonadotropins that act on the gonads,while cortisol is the glucocorticoid itself,not the stimulating hormone.

(C) $FSH$ (Follicle Stimulating Hormone) is known as the gametokinetic factor.
It is called the gametokinetic factor because it stimulates the proliferation and maturation of gametes in both males and females.
In males,it stimulates spermatogenesis in the seminiferous tubules.
In females,it stimulates the growth and development of ovarian follicles.

(B) The Melanocyte Stimulating Hormone $(MSH)$ is produced by the $pars$ $intermedia$ of the pituitary gland in many vertebrates.
In humans,the $pars$ $intermedia$ is almost merged with the $pars$ $distalis$.
$MSH$ acts on melanocytes (melanin-containing cells) and regulates skin pigmentation.
Melatonin is a hormone secreted by the pineal gland,which is distinct from $MSH$.
Therefore,the statement regarding its secretion from the $pars$ $intermedia$ is the most accurate biological description among the choices provided.

(D) The anterior pituitary gland secretes several essential hormones,including Growth Hormone $(GH)$,Luteinizing Hormone $(LH)$,and Follicle-Stimulating Hormone $(FSH)$.
Degeneration or hyposecretion of the anterior pituitary leads to a deficiency of these hormones.
$1$. Deficiency of gonadotropins ($LH$ and $FSH$) leads to reproductive failure or sterility.
$2$. Deficiency of Growth Hormone $(GH)$ results in reduced metabolic activity,leading to extreme weakness.
$3$. Growth Hormone also plays a role in glucose metabolism; its deficiency can lead to lower blood glucose levels,known as hypoglycaemia.
Therefore,all the listed conditions are consequences of anterior pituitary degeneration.

(A) The luteinizing hormone $(LH)$ is secreted by the gonadotropic cells (specifically basophil cells) of the $pars$ $distalis$ or the anterior pituitary gland.
$LH$ plays a crucial role in the reproductive system,including the stimulation of ovulation and the maintenance of the corpus luteum in females,and the stimulation of testosterone production in males.

(A) Pitressin is a commercial name for the hormone $ADH$ (Antidiuretic Hormone),which is also known as vasopressin.
It is synthesized by the hypothalamus and released by the posterior pituitary gland.
It primarily acts on the kidney to stimulate the reabsorption of water and electrolytes,thereby reducing the loss of water through urine.

(B) Vasopressin,also known as Antidiuretic Hormone $(ADH)$,is secreted by the posterior pituitary gland.
Its primary function is to act on the kidney tubules (specifically the distal convoluted tubules and collecting ducts) to promote the reabsorption of water and electrolytes.
This process reduces the loss of water through urine,thereby helping to maintain the body's water balance and blood pressure.
Therefore,the correct option is $B$.

(B) Diabetes insipidus is a condition characterized by the excretion of large amounts of dilute urine and excessive thirst.
It is caused by the hyposecretion (deficiency) of Antidiuretic Hormone $(ADH)$,also known as vasopressin,which is released by the posterior pituitary gland.
$ADH$ promotes the reabsorption of water from the distal convoluted tubules and collecting ducts of the nephrons in the kidneys.
Therefore,a lack of $ADH$ prevents water reabsorption,leading to the symptoms of diabetes insipidus.
Thus,the correct option is $B$.

(B) $FSH$ (follicle stimulating hormone) is secreted by the anterior pituitary gland.
It stimulates the growth and development of ovarian follicles in females and spermatogenesis in males.
It is also known as a gametokinetic factor.

(C) Growth Hormone $(GH)$,also known as somatotropin,promotes growth by stimulating protein synthesis in cells. At the cellular level,$GH$ increases the rate of transcription of $DNA$ into $m-RNA$. This increase in $m-RNA$ production leads to enhanced protein synthesis,which is essential for cell growth,tissue repair,and skeletal development.

(A) The anterior pituitary, also known as the adenohypophysis, secretes several tropic hormones that regulate the activity of other endocrine glands.
These include Thyroid Stimulating Hormone $(TSH)$, which acts on the thyroid gland, and Gonadotropins like Follicle Stimulating Hormone $(FSH)$ and Luteinizing Hormone $(LH)$, which act on the gonads.
The posterior pituitary $(neurohypophysis)$ stores and releases hormones produced by the hypothalamus $(oxytocin$ and $vasopressin)$, rather than synthesizing its own tropic hormones.
Therefore, the correct option is $A$.

(D) Acromegaly is a condition that occurs due to the hypersecretion of $STH$ (Somatotropic Hormone or Growth Hormone) in adults after adolescence.
It is characterized by the abnormal growth of bones,particularly in the limbs,lower jaw,and facial features,often resulting in a gorilla-like appearance,kyphosis (hunchback),and a protruding bony ridge over the eyes.

(D) $TSH$ stands for Thyroid Stimulating Hormone.
It is a glycoprotein hormone produced by the anterior pituitary gland.
It stimulates the thyroid gland to produce and release thyroid hormones ($T_3$ and $T_4$).

(B) The pituitary gland regulates the secretory functions of several endocrine glands through its tropic hormones.
$1$. The adrenal cortex is regulated by $ACTH$ (Adrenocorticotropic hormone) secreted by the anterior pituitary.
$2$. The thyroid gland is regulated by $TSH$ (Thyroid-stimulating hormone) secreted by the anterior pituitary.
$3$. The testes are regulated by gonadotropins ($LH$ and $FSH$) secreted by the anterior pituitary.
$4$. The adrenal medulla is not under the direct control of the pituitary gland; instead,it is regulated by the sympathetic nervous system,which stimulates the release of epinephrine and norepinephrine in response to stress.

(C) Prolactin is a hormone secreted by the anterior pituitary gland.
Its primary function is to stimulate the growth of mammary glands and the production of milk in them.
Therefore,the effect of prolactin is most marked in the mammary glands.

(D) The correct answer is $D$. Gonadotropins are hormones secreted by the anterior pituitary (adenohypophysis) that act on the gonads.
$1$. Gonadotropins include $FSH$ (Follicle Stimulating Hormone) and $LH$ (Luteinizing Hormone).
$2$. In males,$FSH$ stimulates spermatogenesis,while $LH$ stimulates the Leydig cells to secrete androgens.
$3$. In females,$FSH$ stimulates the growth and development of ovarian follicles,and $LH$ induces ovulation and maintains the corpus luteum.
$4$. Prolactin (also known as $LTH$) is responsible for milk production in mammary glands,but it is not classified as a gonadotropin.

(B) Oestrogen exerts a negative feedback effect on the anterior pituitary gland. Specifically,it inhibits the secretion of Follicle Stimulating Hormone $(FSH)$ from the anterior pituitary,which is essential for the regulation of the ovarian cycle.

(B) The condition described is known as acromegaly.
It is caused by the hypersecretion of growth hormone $(GH)$ during adulthood,specifically after the closure of the epiphyseal plates at the ends of the bones.
Patients with acromegaly exhibit a gorilla-like appearance,characterized by a large head,protruding jaws,and enlarged hands and feet.

(C) The anterior pituitary gland secretes Growth Hormone $(GH)$,which is essential for the growth and development of bones and tissues in children.
If the anterior pituitary is severely damaged,the secretion of $GH$ will be significantly reduced or stopped.
Since the boy is only four years old,a deficiency of $GH$ will lead to stunted growth,meaning the boy will not grow much in height.
Other options are incorrect because thyroxin release is regulated by $TSH$ (also from the pituitary),spermatogenesis occurs during puberty,and mammary gland growth is not a primary concern in a young boy.

(C) $ACTH$ (Adrenocorticotropic hormone) is secreted by the basophil cells of the anterior pituitary gland,specifically from the pars distalis region.