Chemical Control & Coordination PDF

Welcome to Chemical Control & Coordination © 2022, Aakash BYJU'S. All rights reserved. Key Takeaway Endocrine system 1 2 Hypothalamus 3 4 Pineal gland © 2022, Aakash BYJU'S. All rights reserved. Human endocrine system 5 Pituitary gland Hormones Thyroid gland Hypothyroidism Hyperthyroidism Thymus 6 7...

Welcome to Chemical Control & Coordination © 2022, Aakash BYJU'S. All rights reserved. Key Takeaway Endocrine system 1 2 Hypothalamus 3 4 Pineal gland © 2022, Aakash BYJU'S. All rights reserved. Human endocrine system 5 Pituitary gland Hormones Thyroid gland Hypothyroidism Hyperthyroidism Thymus 6 7 8 9 Pancreas © 2022, Aakash BYJU'S. All rights reserved. Parathyroid gland 10 Adrenal glands Testes 11 12 Hormones secreted by non-endocrine glands 13 14 Hormone receptors 15 Summary © 2022, Aakash BYJU'S. All rights reserved. Ovary Types of hormones Glands Exocrine glands Endocrine glands  They are glands with ducts.  They are ductless glands.  Glands that secrete substances onto some surface are known as exocrine glands.  Glands that secrete hormones into the bloodstream are endocrine gland.  E.g.: Sweat and sebaceous glands  E.g.: Hypothalamus Endocrine system A system of endocrine glands along with hormone producing tissues or cells that are located in different parts of our body is referred to as endocrine system. Endocrine system is responsible for growth and development in our body. © 2022, Aakash BYJU'S. All rights reserved. Endocrine System Hormones    They are intercellular chemical messengers produced in response to a specific stimulus. They are non-nutrient chemicals transported to target cells. They are produced in trace amounts. Stimulus Hormone enters target cell © 2022, Aakash BYJU'S. All rights reserved. Endocrine gland releases the hormone Hormone enters blood stream Endocrine gland (secreting cell) Blood vessel Hormone enters target cell Hormone Hormone enters blood stream Target cell Human Endocrine System  The major endocrine glands present in the human endocrine system are as follows: Pineal gland Thyroid gland Thymus Pancreas Gonads (Testes) Hypothalamus Pituitary gland Parathyroid gland Adrenal glands Gonads (Ovary) Pituitary gland: Master gland It is called so because, it directs the secretion of hormones of all the other glands in the body. Hypothalamus: Master control center Hypothalamus is called so because, it controls and provides necessary inputs to the pituitary. © 2022, Aakash BYJU'S. All rights reserved. Hypothalamus Location  Structure Hypothalamus is present in the forebrain at the basal part of diencephalon. Hypothalamus contains neurosecretory cells. ○ These cells are also known as nuclei. Hypothalamus Hypothalamus Neurosecretory cell Pituitary gland © 2022, Aakash BYJU'S. All rights reserved. Posterior pituitary Hypothalamus Hormones of hypothalamus The hypothalamus produces hormones that stimulate or inhibit the hormone production in the anterior lobe of the pituitary gland.   Releasing hormone (RH) (Stimulate anterior lobe secretion) Inhibiting hormone (IH) (Inhibit anterior lobe secretion) These hormones stimulate the secretion of hormones from the anterior pituitary. E.g. - GNRH These hormones inhibit the secretion of hormones from the anterior pituitary. E.g. - Somatostatin Hypothalamus RH IH Anterior pituitary Target gland The releasing and inhibiting hormones reach the pituitary gland through a portal circulatory system. The posterior pituitary is under the direct neural regulation of the hypothalamus. © 2022, Aakash BYJU'S. All rights reserved. Pituitary Gland   Location Pituitary gland is attached to the hypothalamus by a stalk. It is located inside a bony cavity known as sella turcica. Hypothalamus Structure  Anatomically, pituitary is divided into: Adenohypophysis (Anterior pituitary lobe) Pars distalis Pituitary Gland © 2022, Aakash BYJU'S. All rights reserved. Sella turcica Pars intermedia Neurohypophysis (Posterior pituitary lobe) Pituitary Gland Hypothalamus Anterior Pituitary  It houses the axonal terminals of hypothalamic neurons.  They store and release hormones. Posterior Pituitary It consists of two portions, pars distalis and pars intermedia.  Pars distalis is also known as anterior pituitary.  In humans, the pars intermedia is almost merged with pars distalis. © 2022, Aakash BYJU'S. All rights reserved.  Hypothalamus Pars intermedia Pars distalis Posterior Pituitary Pituitary Hormones Posterior pituitary Anterior pituitary It stores and secretes two hormones synthesised by the hypothalamus and transported axonally to neurohypophysis. Prolactin (PRL) Growth hormone (GH) Luteinising hormone (LH) Oxytocin Acts on smooth muscles and stimulate contraction Stimulate vigorous contraction of uterus during childbirth Stimulate milk ejection from mammary glands   Follicle stimulating hormone (FSH)  Thyroid stimulating hormone (TSH) Adrenocorticotropic hormone (ACTH) Melanocyte stimulating hormone (MSH) © 2022, Aakash BYJU'S. All rights reserved. Vasopressin    Also called antidiuretic hormone (ADH) Acts on kidneys and stimulate reabsorption of water and electrolytes by DCT Impairment affecting synthesis/release of ADH can cause diabetes insipidus which refers to diminished ability to conserve water Pituitary Hormones Anterior pituitary hormones Growth hormone (GH)   Growth hormone controls growth of the body. The release of growth hormone is controlled by hormones produced by the hypothalamus. o Growth hormone-releasing hormone (GHRH) o Somatostatin/Growth hormoneinhibiting hormone (GHIH) © 2022, Aakash BYJU'S. All rights reserved. Growth hormone Over secretion Low secretion Causes abnormal growth of the body leading to gigantism Results in stunted growth leading to dwarfism Pituitary Hormones Anterior pituitary hormones Luteinising hormone (LH) It is a gonadotropin (stimulates gonadal activity) Role in females Role in males  Stimulates the synthesis and secretion of hormones called androgens (testosterone) from testes Follicle stimulating hormone (FSH) It is a gonadotropin (stimulates gonadal activity)   © 2022, Aakash BYJU'S. All rights reserved. Induces ovulation of fully mature follicles (Graafian follicles) Maintains the corpus luteum, formed after ovulation Role in males  FSH and androgens regulate spermatogenesis (process of origin and development of sperm cells). Role in females  It stimulates growth and development of the ovarian follicles. Pituitary Hormones Anterior pituitary hormones - LH & FSH regulation LH and FSH production is controlled by the production of GnRH (gonadotropin-releasing hormone) and GnIH (gonadotropin-inhibiting hormone) from the hypothalamus. Hypothalamus GnIH GnRH Pituitary FSH, LH Hypothalamus GnIH GnRH Pituitary FSH, LH Testicles Ovaries Androgen Estrogen © 2022, Aakash BYJU'S. All rights reserved. Pituitary Hormones Prolactin (PRL)  It helps in the production of milk after childbirth.  It regulates the growth of the mammary glands.  The release of prolactin is controlled by the hypothalamus. Thyroid stimulating hormone (TSH)  It is triggered by the thyroid-releasing hormone of the hypothalamus.  It stimulates the synthesis and secretion of thyroid hormones. Melanocyte stimulating hormone (MSH)  It acts on the melanocytes (melanin Adrenocorticotropic hormone (ACTH)  It stimulates synthesis and secretion of containing cells) and regulates pigmentation of the skin. © 2022, Aakash BYJU'S. All rights reserved.  steroid hormone called glucocorticoids. It also stimulates the production of cortisol. Pineal Gland Cerebrum Thalamus Hypothalamus  Pineal Gland  ‘Pineal’ is derived from the Latin word ‘Pinea’, which means pinecone  Pea-sized gland  Located on the dorsal side of the forebrain  Secretes melatonin Light inhibits the secretion of melatonin from the pineal gland. © 2022, Aakash BYJU'S. All rights reserved. Pineal Gland Functions of melatonin Body clock and pigmentation   Human body maintains an internal clock that responds to outside cues like light and eating habits. This clock is regulated by melatonin. Menstrual cycle  Melatonin also keeps the duration of the menstrual cycle regular. © 2022, Aakash BYJU'S. All rights reserved. Metabolism and body temperature Body defence  Melatonin also enhances immunity.  Melatonin increases metabolism, which burns body fat. Diurnal rhythm    The 24-hour sleep-wake cycle is the circadian rhythm. The circadian rhythm synced with day and night is the diurnal rhythm. Melatonin maintains the diurnal rhythm. Thyroid Gland  It is present in the neck, in front of the trachea, or the windpipe. Isthmus The connective tissue that connects lobes of thyroid © 2022, Aakash BYJU'S. All rights reserved. Thyroid gland Consists of two lobes: One on each side of the trachea Thyroid Gland  It is made up of follicles and stromal tissue. Follicles Have spaces lined by follicular cells Blood capillary Stromal tissue C cells: Cells outside the follicles Secrete calcitonin, a peptide hormone © 2022, Aakash BYJU'S. All rights reserved. Follicular cells Tissue between the follicles containing blood capillaries Synthesise thyroid hormones from the amino acid tyrosine Thyroid Gland Thyroid hormones Hormones produced by follicular cells Hormones produced by C-cells They are composed of tyrosine Thyrocalcitonin OH OH I I O I I Calcitonin O I CH2 COOH CH NH2 Triiodothyronine (T3) (3 iodine atoms) I Calcium ion I CH2 COOH CH NH2 Tetraiodothyronine or thyroxine (T4) © 2022, Aakash BYJU'S. All rights reserved. (4 iodine atoms)  Calcitonin promotes the removal of calcium ions from blood, so that the blood calcium levels fall.  Calcitonin also promotes the deposition of calcium ions into bones. Thyroid Gland Functions of thyroid hormones Regulation of basal metabolic rate Regulation of metabolism in general Promoting red blood cell formation Growth and brain development in children Disorders Hypothyroidism  Thyroid hormones produced in less quantities than required © 2022, Aakash BYJU'S. All rights reserved. Hyperthyroidism  Thyroid hormones are produced in higher quantities than required Maintenance of water and electrolyte balance Thyroid Gland Hypothyroidism Causes   Effects Low-iodine diet Underactive thyroid gland Goitre Cretinism Decreased rate of metabolism Effects Decreased growth and brain development of baby         © 2022, Aakash BYJU'S. All rights reserved. Enlargement of thyroid gland Fatigue and sluggishness Feeling cold Poor memory and concentration Constipation Weight gain Irregular menstrual cycle Myxoedema Causes  Deficiency of iodine in the diet of pregnant woman or the child  Genetic/congenital defect Effect  Stunted growth  Mental retardation  Abnormal skin  Deaf-mutism Thyroid Gland Hyperthyroidism Causes Effects Graves’ disease  Also called exophthalmic goitre  Characterised by enlargement of thyroid gland, protruding eyeballs, increased BMR, and weight loss © 2022, Aakash BYJU'S. All rights reserved. Thyroid nodule  Lumps in thyroid, which produce excess thyroid hormones  Hyperactivity  Anxiety  Weight loss Parathyroid Gland     Location: Four parathyroid glands are present on the backside or dorsal side and two on each lobe of the thyroid gland. Function: These glands secrete parathyroid hormone, parathormone, or PTH. Chemical nature: PTH is polypeptide in nature. It is a hypercalcemic hormone. It raises blood Ca2+ in the blood. Effect of situations on parathyroid hormone When calcium levels are low in blood   Acts on bones and stimulates resorption of Ca2+ Also stimulates reabsorption of Ca2+ by the renal tubules and increases absorption from the digested food © 2022, Aakash BYJU'S. All rights reserved. When calcium levels are high in blood   Production of parathyroid hormone is reduced Production of calcitonin increases Thymus  Location: It is located in the chest, behind the sternum, between the lungs, and on the ventral (front) side of the aorta.  It is not only an endocrine gland, but also plays a very important role in the development of immune system.  It secretes small peptide hormones known as thymosin.  Function: A major role of the thymus is the differentiation of Tlymphocytes. o o  Hence, it is involved in cell-mediated immunity. It is also involved in humoral immunity, as it produces antibodies, though to a lesser extent. It gradually reduces in size as a person grows older, resulting in a weaker immune system. © 2022, Aakash BYJU'S. All rights reserved. Adrenal Glands   Location: A pair of adrenal glands are located one above each kidney. They are also known as suprarenal glands. It is made of two regions: Adrenal glands Adrenal cortex (Outer) Adrenal medulla (Inner) © 2022, Aakash BYJU'S. All rights reserved. Adrenal Glands Adrenal cortex Capsule Zona glomerulosa (Outer zone) Secretes mineralocorticoids Zona fasciculata (Middle zone) Secretes glucocorticoids Zona reticularis (Inner zone) Secretes gonadocorticoids Cortex © 2022, Aakash BYJU'S. All rights reserved. Adrenal Glands Adrenal cortex Cholesterol All the hormones of adrenal cortex are synthesized from cholesterol. Corticoids Glucocorticoids      Primarily involved in carbohydrate metabolism Cortisol - main and the most abundant glucocorticoid Other two corticoids are cortisone and corticosterone Known as a stress hormone, as it is released during stress Acts mainly on the cells of the liver © 2022, Aakash BYJU'S. All rights reserved. Mineralocorticoids    Responsible for the regulation of water and electrolyte balance Aldosterone- principal and the most abundant mineralocorticoid Acts on the cells of the kidney Gonadocorticoids  Gonadocorticoids are also known as the sex hormones of adrenal glands Adrenal Glands Adrenal cortex Functions of glucocorticoids Gluconeogenesis  Conversion of non-carbohydrates (like glycerol or amino acids) to carbohydrates Anti-inflammatory and immunosuppressant  Suppresses immune response (Production of antibodies)  Mostly produced by cortisol Proteolysis  Breakdown of proteins into amino acids in blood  Inhibits cellular uptake & utilisation of amino acids  Cortisol maintains cardiovascular and kidney functions  Increases RBC production Lipolysis  Breakdown of fats in adipose tissue to fatty acids in bloodstream © 2022, Aakash BYJU'S. All rights reserved. Adrenal Glands Adrenal cortex Functions of mineralocorticoids (Aldosterone) Maintenance of body fluid volume, osmotic and blood pressure:  Expulsion of K+ and phosphate ions  Reabsorption of Na+ and water Functions of gonadocorticoids Male sex corticoids (act on testes) Androgens Produced in large quantities Female sex corticoids (act on ovaries) Progesterone Estrogen Produced in small quantities  They also promote development of secondary sexual characters. © 2022, Aakash BYJU'S. All rights reserved. Adrenal Glands Adrenal medulla Hormones (Made from tyrosine) Catecholamines/Emergency hormone/ Fight or flight hormones Norepinephrine/ Noradrenaline Epinephrine/ Adrenaline  Secreted during stress and emergency situations  Breakdown glycogen and increase blood sugar levels  Act on cells of skeletal, cardiac and smooth muscles, blood vessels and fat cells.  Increase alertness, pupillary dilation, piloerection, sweating, heart rate and breathing  Stimulate the breakdown of lipids and proteins. © 2022, Aakash BYJU'S. All rights reserved. Pancreas  It lies in the bend of duodenum.  It acts both as an exocrine and an endocrine gland. Structure of pancreas Pancreatic acini (Exocrine part) Islets of Langerhans 1-2% (Endocrine part) Hormones produced by Islets of Langerhans ⍺ cells ꞵ cells Produce glucagon Produce insulin © 2022, Aakash BYJU'S. All rights reserved. Pancreas Hormonal impact Hyperglycemia (Diabetes mellitus) Hypoglycemia  Prolonged hyperglycemia leads to a complex disorder known as diabetes mellitus.  It leads to a decrease in the blood glucose level below normal.  It leads to a loss of glucose through urine and the formation of harmful compounds known as ketone bodies.   In diabetes, the body begins to uptake fatty acids from the blood to provide energy. Insulin acts mainly on hepatocytes and adipocytes (cells of adipose tissue), and enhances cellular glucose uptake and utilisation.  This can lead to glucose shortage in blood.  Treatment: Insulin therapy © 2022, Aakash BYJU'S. All rights reserved. Pancreas Glucagon  Acts mainly on the cells of the liver (hepatocytes).     Stimulates glycogenolysis, (conversion of glycogen into glucose in the liver). Stimulates gluconeogenesis (formation of glucose from non-carbohydrate precursors). Glycogenolysis and gluconeogenesis increase the blood sugar level, known as hyperglycemia. Hyperglycemic hormone © 2022, Aakash BYJU'S. All rights reserved. Insulin  Stimulates glycogenesis, which is the conversion of glucose into glycogen.  Insulin enhances the rapid movement of glucose from blood into hepatocytes and adipocytes.  Decreases the blood glucose level, known as hypoglycemia.  Hypoglycemic hormone Testes  A pair of testes are present in the scrotal sacs outside the abdominal cavity of males.  It performs dual functions as the primary sex organ as well as an endocrine gland. Structure of testes Seminiferous tubules Interstitial tissue  Seminiferous tubules contain epithelium consisting of sertoli cells and spermatogonia.  The Leydig cells or interstitial cells are present in the interstitial/stromal tissue.  Sertoli cells nourish sperms and spermatogonia produce sperms.  Leydig cells are responsible for the synthesis of androgens (male sex hormones). © 2022, Aakash BYJU'S. All rights reserved. Testes Role of androgens o o o o o o They play a stimulatory role in the process of spermatogenesis (production of sperms). They act on the central neural system and influence the male sexual behaviour (libido). They regulate protein and carbohydrate metabolism. They regulate the development, maturation, and functions of the male accessory sex organs like epididymis, vas deferens, seminal vesicles, prostate gland, urethra, etc. They promote growth of body tissues like bones and muscles. They play a vital role in the development of secondary sexual characters. © 2022, Aakash BYJU'S. All rights reserved. Ovary  Females have a pair of ovaries located in the pelvic cavity.  It also has dual functions like the testes.  Ovary is the primary female sex organ, which produces one mature ovum during each menstrual cycle.  In addition to that, the ovary also acts as an endocrine gland and produces hormones. Ovary Ovarian follicles  Stromal tissues After ovulation (release of ovary), the ruptured graafian follicle is converted to a structure known as corpus luteum. © 2022, Aakash BYJU'S. All rights reserved. Ovary Hormones of ovaries Corpus luteum Graafian (ovarian) follicles Steroid hormones Produces estrogens   Estradiol is the principal estrogen. Functions of estrogen: o Stimulates development and maturation of growing ovarian follicles o Helps in maturation of ova in the ovaries o Controls female sexual behaviour o Helps in development of female secondary sexual characters o Stimulates mammary gland development © 2022, Aakash BYJU'S. All rights reserved. Produces progesterone  Functions of progesterone: o Stimulates the development of uterine endometrium o Acts on the mammary glands and stimulates the formation of alveoli and milk secretion o Also secreted by the placenta during pregnancy Hormones Secreted by Non-Endocrine Glands  Hormones are secreted not only by endocrine glands.  They are also produced by other organs such as the heart, kidney, and gastrointestinal tract.  These organs have endocrine cells that secrete hormones. Heart Gastrointestinal tract Secretes peptide hormone atrial natriuretic factor (ANF) Gastrin - Stimulates secretion of HCl and pepsinogen Causes dilation of blood vessels, thus reduces blood pressure Secretin - Stimulates secretion of water and bicarbonate ions Cholecystokinin (CCK) - Stimulates secretion of pancreatic enzymes and bile juice Gastric inhibitory peptide (GIP) Inhibits gastric secretion and motility © 2022, Aakash BYJU'S. All rights reserved. Kidney Secretes peptide hormone erythropoietin Stimulates erythropoiesis (production of RBCs) Types of Hormones Based on chemical nature Peptide, polypeptide, and protein Insulin, glucagon, pituitary hormones, hypothalamic hormones, etc. Based on solubility Steroids Iodothyronines Amino acid derivatives Lipid soluble Water soluble Cortisol, testosterone, estradiol, progesterone, etc. Thyroid hormone Epinephrine Steroids and Iodothyronines Peptides, polypeptides, protein hormones, amino acid derivatives Note: Several non-endocrine tissues secrete hormones called growth factors. These factors are essential for the normal growth of tissues and their repairing/regeneration. © 2022, Aakash BYJU'S. All rights reserved. Hormone Receptors Hormones in our body act like chemical messengers that relay signals from the endocrine glands and deliver it to the target tissues by binding specifically to them. Hormone-receptor complex Receptor Hormone © 2022, Aakash BYJU'S. All rights reserved.  Like a specific lock to the key, hormones have specific proteins called receptors.  Hormones and receptors perfectly fit with each other.  These receptors are present only on target cells.  When the hormone binds to a receptor protein, it forms a hormone-receptor complex.  This complex leads to certain biochemical changes in target tissue. Hormone Receptors - Types Intracellular receptors Cell Intracellular receptor Cell Nucleus Intracellular receptors are present inside membrane of the target cell. © 2022, Aakash BYJU'S. All rights reserved. Membrane receptors Membrane receptor Nucleus Membrane receptors are present on the cell membrane of the target cell. Membrane receptors are also called extracellular receptors. These act as first messengers. Hormone Receptors Types of hormones based on interaction with receptors Hormones which interact with membrane-bound receptors Hormones which interact with intracellular receptors  They generate second messengers (e.g., cyclic AMP, IP3 , Ca2+ etc) which in turn regulate cellular metabolism.  They mostly regulate gene expression or chromosome function by the interaction of hormone-receptor complex.  They do not enter the target cell.  They enter the target cell.  E.g., steroid hormones  E.g., protein hormones © 2022, Aakash BYJU'S. All rights reserved. Summary Endocrine system (A system of endocrine glands along with hormone-producing tissues or cells) Hypothalamus (Master control centre) Pituitary gland (Master gland) Pineal gland Thyroid gland Parathyroid gland Thymus Pancreas Adrenal gland Gonads- Testes and ovaries © 2022, Aakash BYJU'S. All rights reserved. Summary Pituitary hormones Anterior pituitary Pars distalis Prolactin (PRL) Growth hormone (GH) Luteinising hormone (LH) Follicle stimulating hormone (FSH) Thyroid stimulating hormone (TSH) Adrenocorticotropic hormone (ACTH) © 2022, Aakash BYJU'S. All rights reserved. Posterior pituitary Pars intermedia Oxytocin Melanocyte stimulating hormone (MSH) Vasopressin Summary Pineal gland  Hormone: Melatonin  Functions: o Maintains diurnal rhythm o Regulates body temperature, metabolism, menstrual cycle o Enhances immunity Parathyroid gland  Regulates blood calcium level by tackling deficiency of calcium in blood Thymus gland Thymosins Thyroid gland  Thyroid hormones o T3 and T4 o Calcitonin  Thyroid disorders o Hypothyroidism o Hyperthyroidism © 2022, Aakash BYJU'S. All rights reserved. T-lymphocytes Antibodies Cell-mediated immunity Humoral immunity Thymus gland plays a vital role in our immune system as the T-lymphocytes mature and differentiate in it. Summary Adrenal gland Cortex Corticoids Mineralocorticoids Aldosterone © 2022, Aakash BYJU'S. All rights reserved. Glucocorticoids Cortisol Androgens Gonadocorticoids Estrogens Summary Adrenal gland Medulla Catecholamines Norepinephrine/ Noradrenaline Epinephrine/ Adrenaline Emergency hormones or hormones of fight or flight © 2022, Aakash BYJU'S. All rights reserved. Summary Pancreas hormones produced by Islets of Langerhans ⍺ cells ꞵ cells Produce glucagon Produce insulin It increases blood glucose levels. It decreases blood glucose levels. Hormonal disorders of pancreas Hyperglycemia (Diabetes mellitus) © 2022, Aakash BYJU'S. All rights reserved. Hypoglycemia Summary Hormones of testes Hormones of ovaries Leydig cells Graafian (ovarian) follicles Corpus luteum Androgen Produce estrogens Produces progesterone Testosterone Aids in spermatogenesis © 2022, Aakash BYJU'S. All rights reserved. Summary Hormones of heart, kidney and GI tract Heart - ANF Gastrointestinal tract Gastrin, secretin, CCK, GIP Kidney Erythropoietin Types of hormones Based on chemical nature Peptide, polypeptide, and protein Steroids © 2022, Aakash BYJU'S. All rights reserved. Iodothyronines Based on solubility Amino acid derivatives Lipid soluble Water soluble Summary Mechanism of action for protein hormone Ovarian cell membrane Hormone (e.g., FSH) Receptor Response 1 (Generation od second messenger) (Cyclic AMP or Ca++) Biochemical responses Physiological responses (e.g., ovarian growth) © 2022, Aakash BYJU'S. All rights reserved. Summary Mechanism of action for lipid hormone Uterine cell membrane Hormone (e.g., estrogen) Nucleus Genome Hormone-receptor complex mRNA Proteins Physiological responses (Tissue growth and differentiation) © 2022, Aakash BYJU'S. All rights reserved.