Chemical coordination and integration NCERT solutions for Class 11

Chemical coordination and integration NCERT solutions for Class 11

Hello students  today we are going to discuss about Class 11 biology chapter 22 chemical coordination and Integration NCERT Solutions. Just keep this statement in your mind! The more you practice, better will be your final CBSE Board performance. Reading our Chemical coordination and Integration NCERT Solutions and understanding all the topics clearly is the only thing you must to do. You should also practice. Spend some quality time in solving our previous years Chemical coordination and Integration questions and answers, question papers and mock tests. It boosts your exam paper writing practice. Here, you might make mistakes while practicing. Learn from your mistakes and take care of not repeating them. In this article will learn about the chapter 22 biology class 11 NCERT solutions for chemical coordination and Integration. Go through them and  Prepare yourself for CBSE board exam

Important points to Remember about Chemical coordination and Integration 

  1. There are special chemicals which act as hormones and provide chemical coordination, integration and regulation in the human body. These hormones regulate metabolism, growth and development of our organs, the endocrine glands or certain cells. 
  2. The endocrine system is composed of hypothalamus, pituitary and pineal. thyroid, adrenal, pancreas, parathyroid, thymus and gonads (testis and ovary). In addition to these, some other organs, e.g., gastrointestinal tract, kidney, heart etc., also produce hormones. 
  3. The pituitary gland is divided into three major parts, which are called as pars distalis, pars intermedia and pars nervosa. Pars distalis produces six trophic hormones. Pars intermedia secretes.only one hormone, while pars nervosa (neurohypophysis) secretes two hormones.
  4. The pituitary hormones regulate the growth and development of somatic tissues and activities of peripheral endocrine glands. 
  5. Pineal gland secretes melatonin,.which plays a very important role in the regulation of 24-hour (diurnal) rhythms of our body (e.g., rhythms of sleep and state of being awake, body temperature, etc.). 
  6. The thyroid gland hormones play an important role in the regulation of the basal metabolic rate, development and maturation of the central neural system, erythropoiesis, metabolism of carbohydrates, proteins and fats, menstrual cycle.
  7. The parathyroid glands secrete parathyroid hormone (PTH) which increases the blood Ca2 levels and plays a major role in calcium homeostasis. 
  8. The thymus gland secretes thymosins which play a major role in the differentiation of T-lymphocytes, which provide cell-mediated immunity. In addition, thymosins also increase the production of antibodies to provide humoral immunity. 
  9. 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. Glucocorticoids stimulate gluconeogenesis, lipolysis, proteolysis, erythropoiesis.

Chemical coordination and Integration Textbook Solutions 

1. Define the following:

(a) Exocrine gland

(b) Endocrine gland

(c) Hormone

Answer :

(a) Exocrine gland: The glands that can carry their products to the body surface such as the mammary glands are called exocrine glands

(b) Endocrine glands: The glands that can carry their secretions to the bloodstream, for example: thyroid, kidney, etc are called  endocrine glands.

(c) Hormone: The hormone is a chemical Messenger produced by glands, specialized tissues and neurons that balance the biological functions of the body, such as metabolism, growth, sexuality, among others.

2. Diagrammatically indicate the location of the various endocrine glands in our body. 

Answer : The diagram indicating the location of the various endocrine glands in our body are:

Chemical coordination and Integration

3. List the hormones secreted by the following:

(a) Hypothalamus

(b) Pituitary

(c) Thyroid

(d) Parathyroid

(e) Adrenal

(f) Pancreas

(g) Testis

(h) Ovary

(i) Thymus

(j) Atrium

(k) Kidney

(l) G-I Tract

Answer : The hormones secreted by the following structures are as follows : 

A. Hypothalamus : Releasing hormone, Lutenising hormone-releasing hormone (LH-RH), Follicle-stimulating hormone-releasing hormone (FSH – RH), Prolactin-releasing hormone (PRH), Growth hormone – releasing hormone, Melanocyte stimulating hormone – releasing hormone, Thyrotropin-releasing hormone (TRH) etc.

B. Pituitary : Follicle-stimulating hormone (FSH), Growth hormone (GH), Leutinising hormone (LH), Thyroid stimulating hormone (TSH), Adrenocorticotropin hormone (ACTH), Melanocyte-stimulating hormone (MSH),  Oxytocin, Anti-diuretic hormone (Vasopressin) etc.

C. Thyroid : Calcitonin, Tri-iodothyronine(T3), Tetraiodothyronine/Thyroxine(T4)

D. Parathyroid :  Parathormone (PTH), 

E. Adrenal : Adrenal cortex-  Mineralocorticoids, Glucocorticoids, Adrenal medulla – Adrenaline, Noradrenaline

F. Pancreas : Glucagon, Insulin, Somatostatin

G. Testis : Testosterone, Androsterone

H. Ovary : Relaxin, Oestrogen, Progesterone,

I. Thymus : Thymosin

J. Atrium : Atrial natriuretic factor (ANF)

K. Kidney : Erythropoietin

L. G-I Tract :  Stomach : Gastrin

Intestine : Secretin, Enterogastrone, Cholecystokinin, Enterocrinin, Duocrinin, Liver : Angiotensinogen

4. Fill in the blanks:

Hormones      Target gland

(a) Hypothalamic hormones__________________

(b) Thyrotrophin (TSH)__________________

(c) Corticotrophin (ACTH)__________________

(d) Gonadotrophins (LH, FSH)__________________

(e) Melanotrophin (MSH)__________________

Answer :

(a) Hypothalamic hormones – Pituitary gland

(b) Thyrotrophin (TSH) – Thyroid gland

(c) Corticotrophin (ACTH) – adrenal cortex

(d) Gonadotrophins (LH, FSH) – Testis and ovaries

(e) Melanotrophin (MSH) – Pigment cells of the dermis of the skin

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 : Parathyroid glands produce parathyroid hormone, which plays a key role in the regulation of calcium levels in the blood. Precise calcium levels are important in the human body. The parathyroid hormone stimulates the following functions:

  1. Release of calcium by bones into the bloodstream
  2. Absorption of calcium from food by the intestines
  3. Conservation of calcium by the kidneys
  4. Stimulates cells in the kidney to transforms weaker forms of vitamin D into the form that is strongest at absorbing calcium from the intestines

(b) Thyroid hormones: Thyroid hormones functions in every cell and all the organs of the body. Such as :

  1. Regulate the rate at which calories are burned, affecting weight loss or weight gain.
  2. Can slow down or speed up the heartbeat.
  3. Can raise or lower body temperature.
  4. Influence the rate at which food moves through the digestive tract.
  5. Control the way muscles contract.
  6. Control the rate at which dying cells are replaced.

(c) Thymosins: Thymosin is a hormone secreted by the thymus. The primary function of thymosins is to stimulate the production of T cells, which are an important part of the immune system. Thymosin also play a important role in the development of B cells to plasma cells to produce antibodies.

(d) Androgens: Androgens are very crucial for male sexual and reproductive function. Androgens are also responsible for the development of secondary sexual characteristics in men, including facial and body hair growth and voice change. Androgens also affect bone and muscle development and metabolism.

(e) Estrogens
  1. The key function of estrogens is development of female secondary sexual characteristics. Like breasts, endometrium, regulation of the menstrual cycle etc. 
  2. In males estrogen helps in maturation of the sperm and maintenance of a healthy libido.
  3. Estrogens increase good cholesterol (HDL) and also increase triglycerides. They decrease LDL and promote fat deposition.
  4. It also stimulates growth of the inner lining of the uterus (endometrium) during the menstrual cycle, increases uterine growth

(f) Insulin and Glucagon  :

  1. Insulin is a peptide hormone produced by beta cells of pancreas. 
  2. Insulin is responsible for the regulating movement of glucose from the blood into the cells. 
  3. In muscle and liver, insulin increases glycogenesis, and decreases glycogenolysis. Decreased gluconeogenesis in liver.
  4. Glucagon is a hormone that is involved in controlling blood sugar (glucose) levels. It is produced by the alpha cells, found in the islets of Langerhans, in the pancreas, from where it is released into the bloodstream.
  5. Glucagon stimulates the conversion of stored glycogen (stored in the liver) to glucose, which can be released into the bloodstream. This process is called glycogenolysis.
  6. It also promotes the glucose production from amino acid. This process is called gluconeogenesis.
  7. It reduces glucose consumption by the liver so that as much glucose as possible can be secreted into the bloodstream to maintain blood glucose levels.

6. Give example(s) of:

(a) Hyperglycemic hormone and hypoglycemic hormone

(b) Hypercalcemic hormone

(c) Gonadotrophic hormones

(d) Progestational hormone

(e) Blood pressure lowering hormone

(f) Androgens and estrogens


(a)Glucagon, Insulin

(b) Parathormone (PTH)

(c) Follicle stimulating hormone (FSH) and Luteinizing hormone (LH)

(d) Progesterone

(e) Atrial natriuretic factor

(f) Testosterone and Estradiol.

7. Which hormonal deficiency is responsible for the following?

(a) Diabetes mellitus

(b) Goitre

(c) Cretinism


The hormonal deficiency that is responsible for the following are:

(a) Diabetes mellitus – Insulin (inadequate secretion) which is caused due to abnormally high glucose levels in the blood.  In muscle and liver, insulin increases glycogenesis, and decreases glycogenolysis. Decreased gluconeogenesis in liver.

(b) Goitre – Thyroxin (inadequate secretion) Thyroxine is the main hormone secreted into the bloodstream by the thyroid gland. It plays vital roles in digestion, heart and muscle function, brain development and maintenance of bones. In adults, thyroxine deficiency will lower the metabolic rate, causing weight gain, memory problems, infertility, fatigue, and muscle stiffness.

(c) Cretinism – Thyroid (inadequate secretion) Cretinism is also known as Congenital hypothyroidism, it is caused due to the deficiency of thyroid hormone in newborns. It causes impaired neurological function, stunted growth, and physical deformities

8. Briefly mention the mechanism of action of FSH.

Answer  : Follicle-stimulating hormone is a gonadotropic hormones and released from the pituitary gland into the bloodstream. Follicle stimulating hormone necessary for adolescent development and the function of the ovaries in women and the testes in men. In women FSH hormone stimulates the development of ovarian cysts before an egg is released from a follicle during ovulation. It also increases estradiol production. In men, follicle-stimulating hormone acts on Sertoli cells in the testes to stimulate sperm production (spermatogenesis).

Mechanism of Follicle stimulating hormone 

  1. Firstly Follicle  stimulating hormone molecule binds to the receptor protein which is located on the surface of the cell and forms the hormone-receptor complex.
  2. Now the formation of hormone causes the receptor complex to activate the adenyl cyclase enzyme.
  3. This enzyme converts ATP to cyclic AMP as a second messenger which inturn activates the follicular cells of membrane of granulose to produce estrogens.
Mechanism of Follicle stimulating hormone

9. Match the following:

Column I      Column II

(a) T4            (i) Hypothalamus

(b) PTH        (ii) Thyroid

(c) GnRH      (iii) Pituitary

(d) LH           (iv) Parathyroid

Answer :

Column I        Column II

(a) T4             (ii) Thyroid

(b) PTH          (iv) Parathyroid

(c) GnRH       (i) Hypothalamus

(d) LH            (iii) Pituitary

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