Punjab State Board PSEB 11th Class Biology Book Solutions Chapter 22 Chemical Coordination and Integration Textbook Exercise Questions and Answers.
PSEB Solutions for Class 11 Biology Chapter 22 Chemical Coordination and Integration
PSEB 11th Class Biology Guide Chemical Coordination and Integration Textbook Questions and Answers
Question 1.
Define the following:
(a) Exocrine gland
(b) Endocrine gland
(c) Hormone
Answer:
(a) Exocrine Gland: It is a gland that pours its secretion on the surface or into a particular region by means of ducts for performic a metabolic activity, e.g., sebaceous glands, sweat glands, salivary glands, etc.
(b) Endocrine Gland: It is a gland that pours its secretion into blood or lymph for reaching the target organ because the gland is not connected with the target organ by any duct. It is also known as ductless gland.
(c) Hormone: 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 glands in our body.
Fig- Location of Endocrine Glands
Question 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:
(a) Hypothalamus secrets Thyrotropin-releasing hormone, Adrenocorticotropin releasing hormone, Gonadotropin-releasing hormone, Somatotropin releasing hormone, Prolactin releasing hormone, Melanocyte stimulating hormone, releasing hormone.
(b)
(i) Pars Distalis Part of Pituitary (anterior pituitary) secrets Growth Hormone (GH), Prolactin (PRL), Thyroid Stimulating Hormone (TSH), Adrenocorticotrophic Hormone (ACTH), Luteinising Hormone (LH), Follicle Stimulating Hormone (FSH).
(ii) Pars Intermedia secrets Melanocyte Stimulating Hormone (MSH), Oxytocin, Vasopressin.
(c) Thyroid secrets Thyroxine (T4) and triiodothyronine (T3)
(d) Parathyroid secrets Parathyroid hormone (PTH).
(e) Adrenal
(i) secrets Adrenaline, Noradrenaline from adrenal medulla. ‘
(ii) also secretes corticoids (glucocorticoid and mineralocorticoid) and sexocorticoids from adrenal cortex.
(f) Pancreas: The a-cells secrete glucagon, while the β-cells secrete insulin.
(g) Testis: Androgens mainly testosterone.
(h) Ovary: Estrogen and progesterone.
(i) Thymus: Thymosins.
(j) Atrium: Atrial Natriuretic Factor (ANF).
(k) Kidney: Erythropoietin
(l) G-I Tract: Gastrin, secretin, cholecystokinin (CCK), and Gastric Inhibitory Peptide (GIP).
Question 4.
Fill in the blanks:
| Hormones | Target gland |
| Hypothalamic hormones | …………………………… |
| Thyrotrophin (TSH) | …………………………….. |
| Corticotrophin (ACTH) | …………………………………. |
| Gonadotrophins (LH, FSH) | ……………………………….. |
| Melanotrophin (MSH) | ……………………………… |
Answer:
| Hormones | Target gland |
| Hypothalamic hormones | Pituitary gland |
| Thyrotrophin (TSH) | Thyroid gland |
| Corticotrophin (ACTH) | Adrenal glands |
| Gonadotrophins (LH, FSH) | Testis and ovary |
| Melanotrophin (MSH) | Hypothalamus |
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): The parathyroid glands secrete a peptide hormone called parathyroid hormone (PTH). PTH acts on bones and stimulates the process of bone resorption (dissolution/demineralization). PTH also stimulates reabsorption of Ca2+ by the renal tubules and increases Ca2+ absorption from the digested food. It plays a significant role in calcium balance in the body.
(b) Thyroid Hormones: Thyroid hormones play an important role in the regulation of the basal metabolic rate. These hormones also support the rocess of red blood cell formation. Thyroid hormones control the metabolism of carbohydrates, proteins and fats. The 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.
(c) Thymosins: The thymus 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.
(d) Androgens: Androgens regulate the development, maturation, and functions of the male accessory sex organs like epididymis, vas deferens, seminal vesicles, prostate gland, urethra, etc. These hormones stimulate muscular growth, growth of facial and axillary hair, aggressiveness, low pitch of voice, etc. Androgens play a major stimulatory role in the process of spermatogenesis (formation of spermatozoa), influence the male sexual behavior (libido).
(e) Estrogens: Estrogens produce wide-ranging actions such as stimulation of growth and activities of female secondary sex organs, development of growing ovarian follicles, appearance of female secondary sex characters (e.g., high pitch of voice, etc.), mammary gland development. Estrogens also regulate female sexual behavior.
(f) Insulin and Glucagon: Glucagon acts mainly on the liver cells and stimulates glycogenolysis resulting in 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 utilization.
Insulin is a peptide hormone, which plays a major role in the regulation of glucose homeostasis. Insulin acts mainly on hepatocytes and adipocytes and enhances cellular glucose uptake and utilization. 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.
Question 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
Answer:
(a) Glucagon and insulin respectively
(b) Parathyroid hormone
(c) Follicle-stimulating hormone and luteinizing hormones
(d) Progesterone
(e) Atrial Natriuretic IFactor (ANF)
(f) Androgens are mainly testosterone and estrogens include estrogen
Question 7.
Which hormonal deficiency is responsible for the following:
(a) Diabetes mellitus
(b) Goitre
(c) Cretinism
Answer:
(a) Diabetes mellitus is due to deficiency of insulin.
(b) Goitre is due to deficiency of thyroxine (T4) and triiodothyronine (T3).
(e) Cretinism is due to deficiency of thyroxine hormone.
Question 8.
Briefly mention the mechanism of action of FSH.
Answer:
Follicle Stimulating Hormone (FSH): In males, FSH and androgens regulate spermatogenesis. FSH stimulates growth and development of the ovarian follicles in females. It stimulates the secretion of estrogens in ovaries.
Question 9.
Match the following columns:
| Column I | Column II |
| A. T4 | 1. Hypothalamus |
| B. PTH | 2. Thyroid |
| C. GnRH | 3. PituItary |
| D. LH | 4. Parathyroid |
Answer:
| Column I | Column II |
| A.T4 | 2. Thyroid |
| B. PTH | 4. Parathyroid |
| C. GnRH | 1. Hypothalamus |
| D. LH | 3. Pituitary |