Adrenal Gland

The adrenal gland is composed of two types of tissues, the​ centrally located tissue is called the adrenal medulla, and outside this lies the adrenal cortex. The adrenal medulla secretes two hormones( catecholamine) called adrenaline or epinephrine and noradrenaline or norepinephrine. These ​are also known as emergency ​hormones ​or hormones of Fight. 

The function of these hormones is as follows:

  • Facilitates the breakdown of glycogen, which results in an increased concentration of glucose in the blood.
  • Increases the heartbeat, rate of respiration, increase alertness, pupillary dilation, piloerection (raising of hairs), sweating, etc.

Structure of Adrenal Gland

The adrenal cortex can be divided into three layers, called zona ​reticularis (inner layer), zona fasciculata (middle layer), and zona ​glomerulosa (outer layer). The adrenal cortex secretes many hormones that are known as corticoids, they are explained as follows:

  • Corticoids carrying out carbohydrates metabolism is known as Glucocorticoid. It stimulates gluconeogenesis, lipolysis, and proteolysis, and inhibits cellular uptake and utilization of amino acids. It also helps 
    in maintaining the cardiovascular system and as well as kidney function. It suppresses the immune response and produces an anti-inflammatory reaction. It also stimulates RBC production. Example Cortisol.
  • Corticoids that regulate the balance of water and electrolytes in our body are called mineralocorticoids. It acts mainly at the renal ​tubules and stimulates the reabsorption of Na+ ​and water and the excretion of K+ and phosphate ions. Thereby, helping in the maintenance of electrolytes balance, body fluid volume, osmotic pressure, and blood pressure. For example, Aldosterone.
  • The adrenal cortex also produces a small amount of Androgenic steroids which play a role in the growth of axial hair, pubic hair, and facial ​hair during puberty.

NCERT Notes for Class 11 Biology Chapter 19: Chemical Coordination and Integration

NCERT Notes Biology Class 11 Chapter 19 Chemical Coordination and Integration: ​The study of chemical coordination and Integration forms an important part of human physiology. Chemical coordination, integration, and regulations in the human body are carried out by special chemicals called hormones. Regulation, growth, ​and development of our organs, the endocrine glands, and cells are carried out by hormones.

Here, in Chapter 19 of Biology Class 11 NCERT Chemical Coordination and Integration, we will study the Human endocrine system, Hormones, and their mechanism of action.

Similar Reads

Endocrine Glands and Hormones

An endocrine gland secrets hormones directly into the bloodstream, through which it is transported to the target cell or organ throughout the body. Examples of endocrine glands include the pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, gonads (ovaries and testes), and pineal gland....

Human Endocrine System

...

The Hypothalamus

Hypothalamus forms the basal part of the diencephalon( forebrain) that regulates various body functions. ​Nuclei, which are neurosecretory cells, also produce hormones. They regulate the synthesis and secretion of the Pituitary gland. Hypothalamus produces two types of hormones,...

Pituitary Gland

The pituitary gland is located in sella turcica (a bony cavity) ​and is attached to the hypothalamus through a stalk. It is divided into two parts:...

Functions of Pituitary Gland Hormones

Hormones Functions Growth hormone Regulates the growth in humans. ​Over secretion – causes Gigantism Under secretion – causes Pituitary dwarfism. ​Excessive secretion in middle age – causes Acromegaly. Prolactin Regulates the growth of the mammary glands and the formation of milk in them. Thyroid-stimulating hormone (TSH) Stimulates the synthesis and secretion of thyroid hormones. Adrenocorticotropic hormone(ACTH) Stimulates the synthesis and secretion of glucocorticoid from the adrenal cortex. Luteinising hormone(LH) ​​Stimulates the synthesis and secretion of Androgen from the testis in males. Androgen regulates spermatogenesis. In females, it induces ovulation of fully mature follicles and maintains corpus lute​um Follicle-stimulating hormone (FSH) Stimulates growth and development of ovarian follicles in females.Regulates spermatogenesis in males. Melanocyte stimulating hormone ​ Acts on melanocyte​ cells present in the skin and regulates pigmentation of the skin. Oxytocin Regulates uterine contraction at the time of childbirth and milk ejection from the mammary gland. Vasopressin ( Antidiuretic hormone) Stimulates resorption of water and electrolyte from the kidney, hence reducing water loss through urine(diuresis)....

Pineal Gland

The Pineal Gland Secrets Melatonin regulates 24 the hour​ rhythm of our body like the sleep-wake cycle, body temperature, etc. It also regulates metabolism, ​pigmentation, the menstrual cycle, and the defense capability of the body....

Thyroid Gland

The thyroid gland consists of two lobes that contacted each other through the isthmus. The thyroid gland is composed of follicles and stromal tissues. Follicles synthesize two hormones: Tetraiodothyronine or thyroxine (T4) and ​Triiodothyronine (T3). Iodine is essential for the normal functioning of the thyroid gland....

Parathyroid Gland

The parathyroid gland which is situated at the back side of the thyroid gland, secrets peptide hormone known as parathyroid hormone. Its level in the body is regulated by the circulating level of calcium ions. PTH is a hypercalcemic hormone, that is, it increases the blood Ca2+ levels, by following processes: stimulating the process of bone resorption, stimulating reabsorption of Ca2+ by the renal tubules, and increasing Ca2+ absorption from the digested food. It plays an important role in maintaining calcium balance in the body....

Thymus

It secrets the peptide hormone, Thymosin. ​It plays an important role in the development of the immune system. It provides Cell-mediated immunity through the differentiation of T – lymphocytes and Humoral immunity, through the production of antibodies....

Adrenal Gland

The adrenal gland is composed of two types of tissues, the​ centrally located tissue is called the adrenal medulla, and outside this lies the adrenal cortex. The adrenal medulla secretes two hormones( catecholamine) called adrenaline or epinephrine and noradrenaline or norepinephrine. These ​are also known as emergency ​hormones ​or hormones of Fight....

Pancreas

Pancreas act as both the Exocrine and Endocrine glands. The Exocrine part consists of Islets of Langerhans ​which contain two types of cells, alpha cells, and beta cells. Alpha ​Cells secrets Glucagon and ​beta cells secrets Insulin....

Testis

Testis acts both as a sex organ and an endocrine gland. It consists of seminiferous tubules and stromal or interstitial tissue. Leydig cells produce a group of hormones called Androgen. For example, Testosterone....

Ovary

The ovary which is the primary female sex organ, produces two groups of steroid hormones called Estrogen and Progesterone....

Hormones of the Heart, Kidney, and Gastrointestinal tract

The atrial wall of our heart secrets a peptide hormone, Atrial natriuretic factor (ANF), which decreases blood pressure through the dilation of blood vessels. The kidney produces a peptide hormone called Erythropoietin which stimulates erythropoiesis (formation of RBC). The gastrointestinal tract secretes four major peptide hormones, namely Gastrin: which stimulates the secretion of hydrochloric acid and ​pepsinogen. ​Secretin: stimulates the secretion of water and bicarbonate ions. Cholecystokinin (CCK): stimulates the secretion of pancreatic enzymes and bile juice. Gastric inhibitory peptide (GIP): inhibits Gastric secretion and mobility....

Mechanism of Hormone Action

​Hormone receptors are the proteins present in the target tissue only. When they are present on the cell ​membrane of the target tissue, they are called membrane-bound receptors and the receptors present inside the target cell are called intracellular receptors. The mechanism of action of hormones is as follows:...

FAQs on Chemical Coordination and Integration

Q1: Define Hormones....

Contact Us