1st PUC Biology Question Bank Chapter 22 Chemical Coordination and Integration

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Karnataka 1st PUC Biology Question Bank Chapter 22 Chemical Coordination and Integration

1st PUC Biology Chemical Coordination and Integration NCERT Text Book Questions and Answers

Question 1.
Define the following
(a) Exocrine gland
(b) Endocrine gland
(c) Hormone
Answer:
(a) Exocrine glands: These glands have ducts. The secretions of these glands are carried by ducts to a particular organ to regulate some metabolic activities.
(b) Endocrine glands: They lack ducts and their secretions (hormones) released directly into the blood for transport to the target tissues.
(c) Hormones: Hormones are non-nutrient chemicals which act as intercellular messengers and are produced in trace amounts.

Question 2.
Diagrammatically Indicate the location of the various endocrine a lands In our body.
Answer:
1st PUC Biology Question Bank Chapter 22 Chemical Coordination and Integration 1

Question 3.
List the hormones secreted by the following:
(a) Hypothalamus
(b) Pituitary
(c) Thyroid
(d) Parathyroid
(e) Adrenal
(f) Pictures
(g) Testis
(h) Ovary
(I) Thymus
(j) Atrium
(k) Kidney
(l) G-i Tract
Answer:
(a) Hypothalamus:

  • Growth hormone-releasing hormone
  • Growth hormone inhibiting hormone (Somatostatin)
  • Gonadotrophin releasing hormone (GnRH)

(b) Pituitary:

  • Growth hormone
  • Prolactin
  • Thyroid-stimulating hormone
  • Adrenocorticotrophic hormone
  • Luteinizing hormone
  • Follicle-stimulating hormone
  • Melanocyte stimulating hormone
  • Oxytocin
  • Vasopressin

(c) Thyroid:

  • Tetraiodo thyronine or thyroxine
  • Triiodothyronine
  • Thyrocalcitonin (TCT)

(d) Parathyroid:

  • Parathyroid hormone (PTH)

(e) Adrenal:

  • Adrenaline/epinephrine
  • Noradrenaline/Norepinephrine
  • Corticoids
  • Cortisol
  • Aldosterone

(f) Pancreas:

  • Glucagon
  • Insulin

(g) Testis:

  • Testosterone

(h) Ovary:

  • Estrogen
  • Progesterone (I) Thymus:
  • Thymosin 0 Atrium:
  • Atrial Natriuretic Factor (ANF)

(k) Kidney:

  • Erythropoietin

(I) G.l. tract:

  • Gastrin
  • Secretin
  • Cholecystokinin (CCK)
  • Gastric inhibitory peptide (GP)

KSEEB Solutions

Question 4.

Fill in the blanks:

Hormones Target gland
(a) Hypothalamic hormones ………..
(b) Thyrotrophln (TSH) ………..
(c) Corticotrophln (ACTH) ………..
(d) Gonadotrophins (LH, FSH) ………..
(e) Meianotrophin (MSH) ………..
Answer:
(a) Pituitary
(b) Thyroid
(c) Adrenal Cortex
(d) Testis and Ovaries
(e) Pineal gland

Question 5.
Write short notes on the functions Of the following hormones:
(a) Parathyroid hormone (PTH)
(b) Thyroid hormones
(c) Thymosins
(d) Androgens
(e) Estrogens
(f) Insulin and Glucagon
Answer:
(a) Parathyroid hormone (PTH)
• When the level of calcium ions in the plasma decreases, PTH is secreted.
• It increases the level of Ca2+ ions in the blood/plasma by
(i) bone reabsorption (demineralization/ dissolution of bones).
(ii) stimulating reabsorption of Ca2+ ions by the renal tubules.
(iii) stimulating the absorption of Ca2+ from the alimentary canal.
(iv) since it increases the level of Ca2+ ions in the blood, it is called hypercalcemic hormone..
• Along with TCT, PTH plays an important role in the calcium balance of the body.

(b) Thyroid hormones: Two types of thyroid hormones –
(i) Tetraiodothyronine(TT4)
(ii) Triiodothyronine (TT3)
Thyroid hormones perform the following functions:
(i) They regulate the basal metabolic rate.
(ii) They control the metabolism of
carbohydrates, fats, and protein.
(iii) They influence the maintenance of water and electrolyte balance.
(iv) They support the process of red blood cell formation.

(c) Thymosin: Thymosin is secreted by the thymus and plays a major role in the differentiation of T-lymphocytes, which provided cell-mediated immunity.
Thymosins also promote the production of antibodies to provide humoral immunity.

(d) Androgens: Androgens are secreted
from the Leydig cells of the testis.
Functions:
(i) Androgens regulate the development, maturation and functioning of the male secondary sex organs.
(ii) They stimulate spermatogenesis.
(iii) They act on the CNS and the influence on male sexual behaviour.
(iv) They produce anabolic effects on proteins and carbohydrate metabolism.

(e) Estrogens: Ovarian hormone.
Functions: Stimulates the growth and
the functioning of female sex organs.
• It stimulates the development of female sex characteristics.
• It regulates female sexual behaviour.

(f) Insulin and Glucagon: Secreted by the pancreas.
• Insulin is a peptide hormone which plays a major role in the regulation of glucose homeostasis. Insulin mainly acts on hepatocytes and adipocytes (cells of adipose tissue) and enhancing cellular glucose uptake and utilisation.
• Glucagon is also a peptide hormone and plays an important role in maintaining normal blood glucose levels.
• Glucagon acts mainly on the liver cells (hepatocytes) and stimulates glycogenolysis resulting in increased blood sugar (hyperglycemia).
• This hormone also stimulates the
process of gluconeogenesis which also contributes to hyperglycemia.
• Glucagon reduces cellular glucose uptake and utilisation. Thus glucagon is a hyperglycemic hormone.

Question 6.
Give example(s) of:
(a) Hyperglycemic hormone and hypoglycemic hormone
(b) Hypercalcemlc hormone
(c) Gonadotrophic hormones
(d) Progestational hormone
(e) Blood pressure lowering hormone
(f) Androgens and estrogens
Answer:
(a) Hyperglycemic hormone: Glucagon. Hypoglycemic hormone: Insulin.
(b) Hypercalcemic hormone: Parathyroid hormone.
(c) Gonadotrophic hormone: Follicle-stimulating hormone(FSH) or luteinizing hormone (LH).
(d Progestational hormone: Progesterone.
(e) Blood pressure lowering hormone: Atrial Natriuretic Factor (ANF)
(f) Androgen : Testosterone. Estrogen : Estrogens, estrone, estradiole.

Question 7.
Which hormonal deficiency is responsible for the following:
(a) Diabetes mellitus
(b) Goitre
(c) Cretinism
Answer:
(a) Insulin
(b) Thyroxine
(c) Thyroxine

KSEEB Solutions

Question 8.
Briefly mention the mechanism of action of FSH.
Answer:
Mechanism of FSH:

  • FSH is a protein hormone.
  • It binds to membrane-bound receptors and stimulates the production of the second messenger, cyclic AMP or Ca”1-1″.
  • The second messenger brings about biochemical responses, which results in the production of physiological response, e.g.- the growth of the ovarian follicles and secretion of estrogens from the follicle cells.

Question 9.
Match the following:
Column I – Column II

(a) T4 – (i) Hypothalamus
(b) PTh – (ii) Thyroid
(c) GnRH – (iii) Pituitary
(d) LH – (iv) Parathyrold
Answer:
(a) – (ii)
(b) – (iv)
(c) – (i)
(d) – (iii)

1st PUC Biology Chemical Coordination and Integration  Additional Questions and Answers

1st PUC Biology Chemical Coordination and Integration One Mark Questions

Question 1.
Mention the hormone produced by pars intermedia of the Pituitary. (April 86)
Answer:
The Melanocyte – stimulating hormone (or M.S.H.)

Question 2.
Where are pituicytes found? (Oct. 90)
Answer:
The ‘Neurohypophysis’.

Question 3.
Which secretes LTH? (April 92)
Answer:
The Adenohypophysis.

Question 4.
Which Endocrine gland produces ACTH? (April 93)
Answer:
The pituitary gland.

Question 5.
Which hormone is called as pregnancy hormone? (April 99, July 2007)
Answer:
Progesterone.

Question 6.
Mention any one function of oxytocin. (Oct. 99)
Answer:
Contraction of smooth muscles of the uterus during parturition.

Question 7.
Name the hormone secreted by Corpus luteum. (April 2000)
Answer:
Progesterone

Question 8.
Expand TSH. (Oct. 2004)
Answer:
Thyroid Stimulating Hormone.

Question 9.
Which disorder is caused due to hypersecretion of somatotropin in children? (Apr. 2007)
Answer:
Gigantism.

Question 10.
Name the gametokinetic factor. (July 2008)
Answer:
FSH.

Question 11.
Give reason (March 2009)
FSH is a gametokinetic factor.
Answer:
FSH stimulates the production of gametes, hence called gametokinetic factor.

Question 12.
What are endocrine glands?
Answer:
Glands which do not have ducts and pour their secretions (hormones) directly into the blood for transport to target tissues are called endocrine glands.

KSEEB Solutions

Question 13.
What are the two types of hormones produced by the hypothalamus?
Answer:
Releasing hormones and inhibiting hormones.

Question 14.
Name the bony cavity in which the pituitary gland is present.
Answer:
Sella turcica.

Question 15.
Name the two divisions (regions) of the pituitary gland.
Answer:
Adenohypophysis and neurohypophysis.

Question 16.
Name the two portions of the adenohypophysis.
Answer:
Pars distalis and pars inter media

Question 17.
What is the other name of neurohypophysis?
Answer:
Pars nervosa.

Question 18.
Which hormone regulates the growth of the mammary glands and the formation of milk in them?
Answer:
Prolactin (PRL)

Question 19.
Expand ACTH.
Answer:
Adrenocorticotrophic hormone.

Question 20.
What are glucocorticoids?
Answer:
‘Glucocorticoids are steroid hormones synthesized and secreted by the adrenal cortex which is stimulated by ACTH.

Question 21.
What stimulates the growth and development of the ovarian follicles in females?
Answer:
Follicle-stimulating hormone (FSH)

Question 22.
Why vasopressin is called the Anti-diuretic hormone?
Answer:
Vasopressin acts on the kidney and stimulates reabsorption of water and reduces the loss of water through urine. Hence it is called Anti-diuretic hormone.

Question 23.
Name the hormone of the pineal gland.
Answer:
Melatonin.

Question 24.
What is the thyroid gland composed of?
Answer:
The thyroid gland is composed of follicles and stromal tissues.

Question 25.
Why is oxytocin called birth hormone? (Delhi 2002 C, Delhi 1999)
Answer:
Oxytocin stimulates a vigorous contraction of the uterus and facilitates childbirth.

Question 26.
If for any reason the release of ADH Is Inhibited, how will this affect the volume of urine produced?
Answer:
The volume of urine decreases.

Question 27.
Name the neurohormone which Inhibits the secretion of growth hormone from the anterior pituitary.
Answer:
Somatostatin.

Question 28.
What is a goiter?
Answer:
Deficiency of iodine results in enlargement of the thyroid gland, a condition known as goiter.

Question 29.
Name the protein hormone secreted by the thyroid gland.
Answer:
Thyrocalcitonin (TCT)

Question 30.
What stimulates the secretion of parathormone?
Answer:
Low calcium ion level in the blood.

Question 31.
Where Is the thymus gland located?
Answer:
The thymus gland is located on the dorsal side of the heart and aorta.

Question 32.
What makes Immunity weak in old Individuals?
Answer:
Thyrnus is degenerated in old individuals resulting in decreased production of thymosins, which makes immune responses of old persons weak.

Question 33.
Name the two types of tissues in adrenal gland.
Answer:
Adrenal medulla and adrenal cortex.

Question 34.
What are catecholamines?
Answer:
Hormones of the adrenal gland, adrenaline and noradrenaline are collectively called as catecholamines.

Question 35.
What happens to the glycogen concentration in the liver cells, when the concentration of adrenaline in the bloodstream increases?
Answer:
Glycogen concentration decreases.

Question 36.
What are corticoids?
Answer:
The hormones secreted by adrenal cortex are called as corticoids.

Question 37.
Name the main glucocorticoid In our body.
Answer:
Cortisol.

Question 38.
Name one mineralocortlcold. (Delhi 2002 C, Foreign 1999)
Answer:
Aldosterone.

Question 39.
Name the hormone secreted by B – cells of islet of Langerhans.
Answer:
Insulin.

Question 40.
Name the cells that produce androgens.
Answer:
Ley dig cells.

Question 41.
What is glycogenesis ?
Answer:
The process of conversion of glucose to glycogen in the liver is called glycogenesis.

Question 42.
Expand CCK
Answer:
Cholecystokinin

1st PUC Biology Chemical Coordination and Integration Two Marks Questions

Question 1.
Distinguish between endocrine and exocrine glands. (April 93)
Answer:
Endocrine glands are specialised invaginations of the surface epithelium which elaborate and secrete chemical substances called hormones into the blood to be carried to the target organ. These are ductless glands and their secretions are produced in minute quantities. Any increase or decrease of hormones leads to clinical conditions (disease or abnormalities).
Eg: Pituitary gland.

Exocrine glands are also produced by surface epithelium. These elaborate and secrete chemical substances called enzymes and transport them to the area of action through ducts (ducted glands)

Eg: Gastric glands: The amount of secretion of enzymes depends on the quantity of substrate they have to act upon.

KSEEB Solutions

Question 2.
Name the two hormones secreted the posterior lobe of the pituitary, giving one functions of calls. (Oct. 97)
Answer:

  • Oxytocin (OT) – Its Chief function is in the contraction of smooth muscles during child birth or parturitions.
  • Vasopressin: (or ADH – Antidiuretic hormone) – Its chief function is to maintain and control water balance in the body and to maintain kidney functions.

Question 3.
What are the functions of Vasopressin ? (April 2002)
Answer:
Functions of Vasopressin or ADH

(a) It controls the water balance of the body by increasing the reabsorption of water in kidney tubules and producing a hypertonic urine.

(b) It also causes the contraction of the smooth muscle fibres of blood vessels thereby raising blood pressure. Under secretion of ADH [Antidiuretic Hormone] causes diabetes insipidus.

Question 4.
Mention any two functions of oxytocin. (March 2008)
Answer:

  • Contraction of smooth muscles during childbirth.
  • Helps in lactation.

Question 5.
Explain how the hypothalamus controls pituitary gland.
Answer:
Hormones originating in the hypothalamic neurons, pass through axons and are released from their nerve endings. These hormones reach the pituitary gland through a portal circulatory system and regulate the functions of the anterior pituitary. The posterior pituitary is under the direct neural regulation of the hypothalamus.

Question 6.
Name the two partitions of the pituitary gland and two hormones secreted by each.
Answer:
Two portions of pituitary gland are:

  • Adeno hypophysis:
    Hormones secreted are Prolactin (PRL) Thyroid stimulating hormone (TSH) etc.
  • Neurohypophysis:
    Hormones secreted are oxytocin and vasopressin.

Question 7.
What are the functions of oxytocin ?
Answer:

  • 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.

Question 8.
Name the gland that functions as a biological clock in our body. Where is this gland located ? Name Its one secretion.
Answer:
Pineal gland functions as a biological clock in our body. It is located on the dorsal side of forebrain. Pineal secretes a hormone called melatonin.

Question 9.
Name the two hormones secreted from the follicles of thyroid. Mention one symptom of hypothyroidism and name the disorder. (All India 2003)
Answer:
Two hormones secreted are

  • Thyroxine
  • Tri iodothyronine.

Hypothyroidism in children results in stunted growth, mental retardation, low intelligence quotient and abnormal skin. The disorder is known as cretinism.

Question 10.
What are the functions of thyroid hormones?
Answer:

  • Thyroid hormones play an important role in regulation of the basal metabolic rate.
  • They support the process of RBC formation
  • They control metabolism of carbohydrates, fats and proteins.
  • Maintenance of water and electrolyte balance.

Question 11.
A person is suffering from calcium deficiency in spite of taking a calcium rich diet. Explain how this condition may have occurred ? (Delhi 2005 C)
Answer:
It may be due to the hyposecretion of parathyroid hormone. Damage in parathyroid gland may have lead to this condition. PTH plays an important role in absorption of calcium from the digested food and reabsorption of calcium by the renal tubules. Hence, hyposecretion of PTH results in calcium deficiency in spite of taking calcium rich diet.

Question 12.
Where is thymus gland located in the human body ? (All India 2005 C)
Answer:
Thymus gland is located on the dorsal side of the heart and aorta. Thymus gland secretes hormone thymosins which play a major role in the development of the immune system.Thymosins play a major role in the differentiation of T- lymphocytes, which provide cell-mediated immunity and also promote production of antibodies to provide humoral immunity.

Question 13.
Name the two hormones secreted by adrenal medulla and their function.
Answer:
The two hormones secreted by adrenal medulla are

  • Adrenaline {Epinephrine)
  • Noradrenaline (norepinephrine)

Functions:

  • They are secreted in response to stress and any emergency situation. ,
  • These hormones increase alertness, pupillary dilation, piloerection, sweating etc.
  • They stimulate breakdown of glycogen, lipids and proteins.

Question 14.
What is diabetes mellitus ? How is it treated?
Answer:
Prolonged hyper glycemia leads to the disorder diabetes mellitus which is associated with loss of glucose through urine and formation of harmful compounds known as ketone bodies. Diabetes patients are treated with insulin therapy.

Question 15.
Name the hormones produced by Ley dig cells. Give any two functions of it.
Answer:
Ley dig cells produces hormones called androgens mainly testosterone.
Functions:

  • Androgens regulate the development, maturation and functions of male accessory sex organs.
  • They play a major stimulatory role in the process of spermatogenesis.

Question 16.
Name two steroid hormones from ovary with one function of each.
Answer:

  • Estrogen: They regulate female sexual behaviours and stimulate the growth and activities of female secondary sex organs.
  • Progesterone: They support pregnancy and acts on mammary gland and help in milk secretion.

Question 17.
Name four major peptide hormones.
Answer:

  • Gastrin
  • Secretin
  • Cholecystokinin
  • Gastric inhibitory peptide.

1st PUC Biology Chemical Coordination and Integration Three Marks Questions

Question 1.
Name three hormones produced by adenohypophysis with function for each.
Answer:

  • Prolactin (PRL): Regulates the growth of mammary gland and formation of milk in them
  • Thyroid stimulating hormone (TSH): It stimulates the synthesis of secretion of thyraid hormones from the thyroid gland.
  • Follicle stimulating hormone (FSH): It regulates growth and development of the ovarian follicles in females.

Question 2.
Name the three layers of adrenal cortex. Name two hormones secreted by adrenal cortex.
Answer:
The three layers are:-

  • Zona reticularis (inner layer)
  • Zona fasciculata (middle layer)
    Zona glomerulosa (outer layer). The adrenal cortex secretes many hormones called as corticoids. The two main hormones are cortisol and aldosterone.

Question 3.
Name the divisions of hormones on basis of their chemical nature with one example for each.
Answer:
Hormones can be divided into four groups on basis of their chemical nature.

  • Peptide, polypeptide, protein hormones Eg: insulin, glucagon
  • Steroids Eg: cortisol, testosterone
  • Lodothyronines Eg: thyroid hormones
  • Amino – acid derivatives Eg: epinephrine

Question 4.
Briefly explain the mechanism of hormone action.
Answer:
Hormones produce their effects on target tissues by binding to specific proteins called hormone receptors located in the target tissues only. Hormone receptors present on the cell membrane of the target cells are called membrane boird receptors and the receptors present inside the target cell are called intracellular receptors, mostly nuclear receptors. Binding of a hormone to its receptor leads to the formation of a hormone-receptor complex. Each receptor is specific to one hormone. Hormone Receptor complex formation leads to certain biochemical changes in the target tissue. Target tissue metabolism and hence physiological functions are regulated by hormones.

1st PUC Biology Chemical Coordination and Integration Five Marks Questions

Question 1.
Name the pituitary hormones and state one function each.
(April 83, 98, 99, 2006, March 2011)
OR
List any five hormones of the adenohy-pophysis (anterior lobe) and mention one function each of them. (July 2008,2009)
Answer:
The pituitary gland produces a totally 9 hormones; 6 of them from the anterior lobe, 1 from the intermediate lobe and 2 from the posterior lobe. The list with one function each is given below.

(1) Growth hormone (GH) or Somototrophin: The basic function of this hormone is to stimulate body weight and rate of growth of the body in terms of muscle, bone structure, cartilage etc.

(2) Thyroid stimulating hormone (STH): regulates the growth of the thyroid gland and increase in thyroid activity.

(3) Adrenocortlcotrophic hormone (ACTH): Regulates the hormonal secretions of the Adrenal cortex (Steroid hormones) and Increase Adrenocortical activity.

(4) Gonadotrophic hormones: Stimulating the growth and activity of gonads

  • Follicle stimulating hormone (FSH): stimulates ovarian follicular growth in female (Ovary) and stimulates the increased production of sperms in male (Testis – semiferous tubules)
  • Luteinizing hormones (LH): Stimulates final maturation of graafian follicle in the ovary. Along with FSH it also stimulates production of progesterone in females. ICSH- in males, it stimulates the testis to produce androgens.

(5) Prolactin (PRL): Stimulates growth of mammary glands and production of milk in females.

(6) Melanocyte – stimulating hormone: Stimulates the increased production of Melanin pigment and its dispersal in mammalian skin.

(7) Vasopressin (or Antidiuretic hormone – ADH): Acts on kidney tubules and controls the water (metabplism) balance, i.e. increases reabsorption of water in kidney tubules (distal part) whenever the body faces a deficit in water.

KSEEB Solutions

Question 2.
What is neurohypophysis? Mention the hormones secreted by it with their target organs and functions? (April-85, Oct. 92)
Answer:
The neurohypophysis forms the posterior lobe of the pituitary. It is also called pars nervosa. It is made up of nervous tissue and terminations of neurosecretory fibres of neuro-secretory cells located in the perotic and paraventricular nuclei of the hypothalamus. It acts as a storage area for the hormones secreted by the neurosecretory cells. These hormones are also called neurohormones.

Neurohypophysis releases 2 types of hormones.

(1) Oxytocin (OT) – Its target organs are the uterus and mammary glands. In the uterus it helps in the contraction of smooth muscles during parturation or child birth. In the mammary glands it acts as a milk letting down hormone (Lactation)

(2) Vasopressin (ADH) – Target organ kidney, specifically the distal convoluted tubules of the nephrons Its function is stimulation of reabsorption of water, during deficit of water in the body.

Question 3.
What is endocrine gland? Name the hopiones secreted by the anterior lobe of pituitary gland and give one function each. (Oct. 85)
Answer:
Endocrine glands are ductless glands which are specialised invaginations of the surface epithelium elaborating and secreting chemical substances called hormones in small quantities into blood through which it is transported to respective target organs.

The pituitary gland produces a totally 9 hormones; 6 of them from the anterior lobe, 1 from the intermediate lobe and 2 from the posterior lobe. The list with one function each is given below.

(1) Growth hormone (GH) or Somototrophin: The basic function of this hormone is to stimulate body weight and rate of growth of the body in terms of muscle, bone structure, cartilage etc.

(2) Thyroid stimulating hormone (STH): regulates the growth of the thyroid gland and increase in thyroid activity.

(3) Adrenocortlcotrophic hormone (ACTH): Regulates the hormonal secretions of the Adrenal cortex (Steroid hormones) and Increase Adrenocortical activity.

(4) Gonadotrophic hormones: Stimulating the growth and activity of gonads

  • Follicle stimulating hormone (FSH): stimulates ovarian follicular growth in female (Ovary) and stimulates the increased production of sperms in male (Testis – semiferous tubules)
  • Luteinizing hormones (LH): Stimulates finai maturation of graafian follicle in the ovary. Along with FSH it also stimulates production of progesterone in females. ICSH- in males, it stimulates the testis to produce androgens.

(5) Prolactin (PRL): Stimulates growth of mammary glands and production of milk in females.

(6) Melanocyte – stimulating hormone: Stimulates the increased production of Melanin pigment and its dispersal in mammalian skin.

(7) Vasopressin (or Antidiuretic hormone – ADH): Acts on kidney tubules and controls the water (metabplism) balance, i.e. increases reabsorption of water in kidney tubules (distal part) whenever the body faces a deficit in water.

Question 4.
Why is the pituitary gland called as a master gland? What are the hormones secreted by it and their actions on the different organs of the body? (Mar. 89)
Answer:
The pituitary gland is called the ‘master gland’ due to the multiplicity of its functions and because its hormones control the growth and secretions of many other endocrine glands. [Note: For the second part of the question, refer answer Q. 1 in this section)

Question 5.
Mention any five hormones of Adenohypophysis with one function each? (April 91)
Answer:
The pituitary gland produces a totally 9 hormones; 6 of them from the anterior lobe, 1 from the intermediate lobe and 2 from the posterior lobe. The list with one function each is given below.

(1) Growth hormone (GH) or Somototrophin: The basic function of this hormone is to stimulate body weight and rate of growth of the body in terms of muscle, bone structure, cartilage etc.

(2) Thyroid stimulating hormone (STH): regulates the growth of the thyroid gland and increase in thyroid activity.

(3) Adrenocortlcotrophic hormone (ACTH): Regulates the hormonal secretions of the Adrenal cortex (Steroid hormones) and Increase Adrenocortical activity.

(4) Gonadotrophic hormones: Stimulating the growth and activity of gonads

  • Follicle stimulating hormone (FSH): stimulates ovarian follicular growth in female (Ovary) and stimulates the increased production of sperms in male (Testis – semiferous tubules)
  • Luteinizing hormones (LH): Stimulates finai maturation of graafian follicle in the ovary. Along with FSH it also stimulates production of progesterone in females. ICSH- in males, it stimulates the testis to produce androgens.

(5) Prolactin (PRL): Stimulates growth of mammary glands and production of milk in females.

(6) Melanocyte – stimulating hormone: Stimulates the increased production of Melanin pigment and its dispersal in mammalian skin.

(7) Vasopressin (or Antidiuretic hormone – ADH): Acts on kidney tubules and controls the water (metabplism) balance, i.e. increases reabsorption of water in kidney tubules (distal part) whenever the body faces a deficit in water.

Question 6.
Mention the hormones secreted by hypothalamus and stored in neurohypophysis Add a note on their function. (Oct. 85)
Answer:
The hormones secreted by hypothalamus and stored in the neurohypophysis are the Oxytocin and Vasopressin (or ADH)

Oxytocin: The main function of oxytocin is aiding in child birth or parturation by acting on the smooth muscles lining the uterus and bringing about the contraction of the uterus required for parturation. It also, brings about contraction of the smooth muscles in the body but to a negligible intensity. Oxytocin also acts as a milk letting down hormone by acting on the mammary glands after parturation by stimulating Lactation in these glands. Apart from this, it acts on the adenohypophysis to induce production of Luteotrophic hormone which intern causes milk secretion.

Vasopressin (or ADH):
Its primary or basic function is to increase the reabsorption of water in the kidney tubules (or more precisely the distal convoluted tubule) whenever the body faces a deficit in water. Since this exhibits antidiuretic properties its also called as the Antidiuretic hormone. Deficiency of this hormone causes unnecessary and excess

Question 7.
Match the following

(a) Pars distalls – (i) Peptid.
(b) Pars nervosa – (ii) Thyroid
(c) Thyrocalcitonin – (iii) Anterior pituitary
(d) Insulin – (iv) Steroids
(e) Cortisol – (v) Posterlon pituitary
Answer:
(a) – (iii)
(b) – (v)
(c) – (ii)
(d) – (i)
(e) – (iv)

KSEEB Solutions

Question 8.
Fill in the blanks:
(a) …….. hormone decreases blood pressure.
(b) …….. hormone stimulates RBC production
(c) Thymosins provide ……..and …….. immunity.
(d) Enlargement of thyroid gland is called as ……..
(e) Catecholamines are …….. and ……..
Answer:
(a) Atrial natriuretic factor (ANF)
(b) Cortisol
(c) Cell mediated, humoral
(d) Goitre
(e) Adrenaline, noradrenaline

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