RBSE Solutions For Class 12 Biology Chapter 29: Chemical Coordination in Human | Textbook Important Questions & Answers

RBSE Class 12 Biology Chapter 29 – Chemical Coordination in Humans. In this chapter, students can learn in detail about hormones, endocrine system, types of endocrine glands, structure and functions of endocrine glands, types of hormones produced by the thyroid gland, adrenal gland, pituitary gland, along with their disorders. It also includes detailed explanations related to the diseases caused by the hypo and hypersecretion of endocrine hormones.

These important questions help students to perform exceptionally well in their exams. By practising these important questions, students can analyze their preparation, get a thorough knowledge about all the important terminologies and perform their best in the examinations.

RBSE Solutions for Class 12 are the best study material for both class assignments and other board examinations. By practising these important questions, students can gain deep knowledge about the topics explained in this chapter and also help them to be well prepared for their upcoming examinations.

RBSE Class 12 Biology Chapter 29 Important Questions

RBSE Biology Chapter 29: MCQ Type Questions

Q.1. Secretions of endocrine glands are called________.

(a) Mucous

(b) Enzyme

(c) Hormone

(d) Pheromone

Sol: (c) Hormone.

Q.2. Who is known as the father of Endocrinology?

(a) Claude Bernard

(b) Thomas Edison

(c) Balis and Starling

(d) Bating and Best

Sol: (b) Thomas Edison.

Q.3. Endocrine glands are ________.

(a) Acidic glands

(b) Alkaline glands

(c) Ductless glands

(d) Glands with ducts

Sol: (c) Ductless glands

Q.4.Which of the following hormones develops hyposecretion in humans?

(a) Thyroxin

(b) Oxytocin

(c) Calcitonin

(d) Vasopressin

Sol: (d) Vasopressin.

Q.5.Which of the following hormones controls the production of calcium and phosphorus?

(a) Parathyroid

(b) Pancreas

(c) Thymus

(d) Thyroid

Sol: (a) Parathyroid

Q.6. Which of the following hormones is secreted by the Alpha cells of the Islets of Langerhans?

(a) Insulin

(b) Glucagon

(c) Melatonin

(d) Somatostatin

Sol: (b) Glucagon.

Q.7.Which of the following glands stimulates fear, fight and flight during the emergency?

(a) Adrenal

(b) Thyroid

(c) Pituitary

(d) Thymus

Sol: (a) Adrenal.

Q.8. Which of the following hormones is released by corpus luteum?

(a) Estrogen

(b) Androgen

(c) Progesterone

(d) Testosterone

Sol: (c) Progesterone.

Q.9. In humans, a disease caused by iodine deficiency is called ________.

(a) Diabetes

(b) Goitre

(c) Sterility

(d) Addison’s disease

Sol: (b) Goitre.

Q.10. Androgen hormone is secreted by________.

(a) Ovaries

(b) Pituitary

(c) Thyroid

(d) Testes

Sol: (d) Testes.

RBSE Biology Chapter 29: Short Answer Type Questions.

Q.1. What is a hormone?

Sol. Hormones are chemical messengers released by the body to control and regulate the activity of certain cells and organs. The hormones are synthesized by endocrine glands.

Q.2.What are endocrine glands?

Sol. Endocrine glands are the specialized ductless glands, which function by synthesizing and transporting their secretions directly to the site of action through the blood. Adrenal glands, pituitary glands, pineal glands, thyroid glands are examples of endocrine glands

Q.3. Name the hormone produced by the pineal gland.

Sol. The hormone produced by the pineal gland is Melatonin. It functions by regulating the body’s sleep cycle.

Q.4. What is Gigantism?

Sol. Gigantism is an abnormal growth in children. It is a hormonal disorder caused by the oversecretion or the excessive production of the growth hormones, which are released by the pituitary gland.

Q.5. What are the types of Hormones?

Sol. Hormones are classified into two types: Peptide hormones and steroid hormones.

Peptide hormones– These are water-soluble hormones, insulin produced by the pancreas is the best example for peptide hormones.

Steroid hormones- These are fat-soluble hormones. All sex hormones – testosterone, estrogen and progesterone are examples of steroid hormones.

Q.6. What is endocrinology?

Sol. Endocrinology is the complete study of hormones, their types, structure, functions along with their deficiency disorders. Endocrinology also includes the study of the endocrine, exocrine and other glands, which are involved in the production and secretions of different types of hormones.

Q.7. Name any 3 diseases caused by hormonal imbalance.

Sol. There are many diseases caused by hormonal imbalance. The major hormonal disorder is:

  1. Diabetes.
  2. Osteoporosis.
  3. Hyperthyroidism.

Q.8. Which hormone is secreted by Beta cells of Islets of Langerhans?

Sol. Insulin is secreted by Beta cells of Islets of Langerhans. It is the major hormone required for the regulation of carbohydrate, fat and protein metabolism.

Q.9. Which hormone is secreted by Thyroid gland?

Sol. The thyroid gland is responsible for producing three important hormones:

  1. Thyroxine.
  2. Triiodothyronine
  3. Calcitonin.

Q.10. What is the pituitary gland?

Sol. The pituitary gland is a small pea-sized gland that plays a major role in the storage and secretion of hormones into your bloodstream. It is known as the master gland of the endocrine system.

Q.11. Which hormone is secreted by Thymus gland?

Sol. The thymus gland produces several hormones including thymopoietin, thymosin, thymulin and thymic humoral factor. These hormones play an important function both in the endocrine system and the immune system.

Q.12.Which hormone is secreted by parathyroid gland?

Sol. The hormone secreted by parathyroid glands is called the parathyroid hormone.

There are three types of Parathyroid hormone.

  1. Primary hyperparathyroidism.
  2. Secondary hyperparathyroidism.
  3. Tertiary hyperparathyroidism.

Q.13. What is thymosin?

Sol. Thymosin, also called the thymus hormone is produced by the thymus gland, which is located in between the lungs, right behind the breastbone and anterior to the chest.

Q.14. Which hormone is called the life-saving hormone?

Sol. The hormones produced by the adrenal glands are called the life-saving hormones. Adrenaline, noradrenaline and steroid hormone are three hormones produced by the adrenal glands.

Q.15. What is the pineal body?

Sol. The pineal body is also called the pineal gland. It is the small, pea-shaped gland found in the human brain. It is an endocrine gland, which functions by producing and secreting the hormone called melatonin.

Q.16. What are the Islets of Langerhans?

Sol. The Islets of Langerhans are the regions of the pancreas, which comprises endocrine cells, which function by producing glucagon, insulin and somatostatin. These hormones regulate glucose levels in the blood cells.

Q.17. Which hormone is secreted by Adrenal cortex?

Sol. The adrenal cortex is the largest part of an adrenal gland, which is found in the outer region of the adrenal gland. Cortisol and aldosterone are two hormones secreted by the Adrenal cortex. These hormones are also called the life-saving hormone, as they are involved in controlling the stress, blood pressure and in the regulation of the body’s metabolism.

Q.18. What is the secretin hormone?

Sol. Secretin hormone is the digestive hormone, produced by the S cells of the small intestine. This hormone is involved in inhibiting the secretion of gastrin, neutralizing the acid and release of hydrochloric acid into the stomach.

Q.19. Who is known as the father of endocrinology?

Sol. Thomas Edison is known as the father of endocrinology. He was the first person to show the relationship between the secretion of the adrenal gland and the causes of Addison’s disease.

Q.20. What are the hormones secreted by Islets of Langerhans?

Sol. Islets of Langerhans are the cluster of cells, which are present within the pancreas that contains three main endocrine cells:

  1. Alpha (ɑ) cells secrete glucagon.
  2. Beta (β) cells secrete insulin.
  3. Delta (𝛅) cells secrete somatostatin.

RBSE Biology Class 12: Long Answer Type Questions

Q.1. Write the differences between endocrine glands and exocrine gland

Sol. The differences between endocrine glands and exocrine gland are:

Endocrine glands Exocrine gland
Endocrine glands are complex. Exocrine glands are simple.
Endocrine glands are ductless glands. Exocrine glands are glands that have duct.
Endocrine glands secrete hormones. Exocrine glands secrete enzymes.
Endocrine gland pours its secretion into lymph or venous blood. Exocrine glands do not pour its secretion into lymph or blood.
The secretion from the endocrine glands is transported to the target through the blood. The secretion from the exocrine glands is poured directly over the target.
Examples of Endocrine glands: Thyroid gland, pineal gland, thalamus gland, pituitary gland, liver, pancreas, ovaries, testes etc. Examples of exocrine glands include salivary glands, liver, mammary glands, sebaceous glands, pancreas, etc.

Q.2. What are the functions of thyroxine hormones?

Sol. Thyroxine hormones are secreted by the thyroid gland. Its functions include:

  1. It increases the rate of heartbeat.
  2. It increases the activity of the neurosecretion in adrenalin and non-adrenalin.
  3. It increases protein synthesis, gluconeogenesis, the body temperature and functions of the nerves.
  4. It increases oxidative metabolism, which increases the rate of energy production in our body cells.
  5. It increases the absorption of glucose, by the consumption of oxygen in the liver and other basic metabolisms.

Q.3. Write the names of releasing and inhibiting hormones secreted by the hypothalamus.

Sol. The hypothalamus is a small region of the brain, which is located at the base of the brain, near to the pituitary gland. It plays a primary role in releasing hormones.

The table below provides the names of different hormones secreted by the hypothalamus along with its functions.

Neurohormones Functions
Releasing Hormones.
Growth hormones Stimulation of secreting Growth Hormone
Thyrotropin Releasing Hormones(TRH) Stimulation of secreting Thyrotropin
Prolactin Releasing Hormones (PRH) Stimulation to release Prolactin
Melanocyte Stimulating Releasing Hormones (MSRH) Stimulation to release Melanocyte Stimulating Releasing Hormones
Corticotropin-releasing hormone (CRH) Stimulation of corticotropin hormones secretion.
Luteinizing releasing hormone (LRH) Stimulation to release luteinizing hormones.
Follicle Stimulating releasing hormone (FSRH) Stimulation of follicle-stimulating hormones secretion.
Inhibitory Hormones
Growth Hormones Inhibition of growth hormone secretion.
Prolactin Inhibitory Hormones (PIH) Inhibition of prolactin secretion.
Melanocyte Stimulating inhibitory Hormones (MSIH) Inhibition of melanocyte-stimulating hormone secretion

Q.4. What are Adrenal Glands?

Sol. The adrenal glands are found on top of each kidney, therefore it is also called the “Cap of the kidney”. There is a pair of adrenal glands

Structure of Adrenal Gland

Adrenal Glands

The glands are usually about 5×3 cm in size and its weight ranges from 7 to 10 grams. These glands are yellowish in colour and comprise three distinct layers :

Adrenal Capsule

It is a capsule, which functions by providing protection to each of the adrenal glands. They build a protective layer, which is composed of fat around the adrenal glands.

Adrenal Cortex

It is the outermost layer of the adrenal gland which functions by producing aldosterone, cortisol, and androgens hormones. There are three layers of cortex called zones- Zona glomerulosa, Zona fasciculata and Zona reticularis.

Adrenal Medulla

The last and innermost part of the adrenal gland is the medulla. It contains the Chromaffin cells, which produce the body’s main source of catecholamines and endorphins hormones. These hormones are stored and released in response to stress.

Functions of Adrenal Gland

These glands produce a variety of hormones, which includes: Epinephrine, norepinephrine, hydrocortisone and corticosterone. The hormones produced by the adrenal glands are called the life-saving hormones.

Q.5. What are the hormones secreted by adenohypophysis?

Sol. Adenohypophysis is the main organ of the endocrine system. It is present in the anterior pituitary. The hormones secreted by adenohypophysis are:

  • Growth hormone.
  • Thyroid-stimulating hormone.
  • Adrenocorticotropic hormone.
  • Follicle-stimulating hormone.
  • Luteinizing hormone.
  • Prolactin.
  • Melanophore stimulating hormone.

Q.6. Why are people living in the hills more prone to the Goiter disease?

Sol. Goiter Disease is an Autoimmune disorder caused due to Iodine deficiency. The drinking water available at high altitude lacks dissolved iodine. Moreover, there is a lack of aquatic food at the hills, which is a good source of iodine.

This is the reason people living in the hills are more prone to Goiter disease.

Q.7. What are endocrine glands? Write the names of all the important endocrine glands in humans.

Sol. Endocrine glands are the specialized ductless glands. These glands function by synthesizing and secrete hormones and transporting their secretions directly to the site of action through the blood. They are present in different places in the human body.

Listed below are the important endocrine glands in humans.

  • Hypothalamus.
  • Pituitary gland.
  • Thyroid gland.
  • Parathyroid gland.
  • Thymus gland.
  • Pineal gland.
  • Pancreas.
  • Adrenal gland.
  • Testes.
  • Ovary.

Q.8. Draw a neat labelled diagram of a Pituitary gland and list out the pituitary hormones.

Sol. The pituitary gland is responsible for the synthesis and secretion of several key hormones in the body.

Structure of the Pituitary Gland.

Pituitary Gland

These hormones include:

  • Human Growth Hormone (HGH)
  • Thyroid Stimulating Hormone (TSH)
  • Adrenocorticotropic Hormone (ACTH)
  • Luteinising Hormone (LH)
  • Follicle-Stimulating Hormone (FSH)
  • Prolactin (PRL)
  • Melanocyte-Stimulating Hormone (MSH)
  • Antidiuretic Hormone (ADH)
  • Oxytocin.

Q.9. What is myxedema disease?

Sol. Myxedema disease is another term for hypothyroidism. It is a hormonal disorder in which thyroid gland is underactive and does not produce or release enough thyroid hormones or thyroxin.

Symptoms of Myxedema disease

A person with myxedema may notice swelling in their face, legs, or tongue. Their skin may also become dry and pale. Depending on the severity of the hormonal deficiency, the signs and symptoms vary from person to person.

Here are a few common signs and symptom of Myxedema disease :

  • Fatigue.
  • Cold intolerance.
  • Decreased libido.
  • Decreased breathing
  • Coarse and pale skin.
  • Frequent constipation.
  • Abnormal menstrual cycles.
  • Coarse and dry hair with hair loss.
  • Excessive sleepiness and lack of energy.
  • Muscle cramps with frequent muscle aches.

Treatment for of Myxedema disease

Myxedema disease is treated with thyroxine hormone supplements. Other administering thyroid hormone replacement medication into a vein, antibiotics, steroid treatment, can also be given to control the symptoms.

Q.10. Describe the hormones secreted by Neurohypophysis.

Sol. It is a posterior pituitary, which is mainly responsible for the storage and secretion of hormones. The pars nervosa stores and releases two hormones which are secreted by the supraoptic nucleus and paraventricular nucleus. Both the oxytocin and vasopressin are octapeptide and comprises of 8 amino acids

Oxytocin

Oxytocin is a hormone secreted by the posterior lobe of the pituitary gland and found only in the females. It is also called Pitocin. It helps in parturition by stimulating contraction of the uterine muscles. It also helps in the release of the milk from the mammary gland after parturition.

Vasopressin

Vasopressin is also called an Antidiuretic Hormone (ADH) or Pitressin. It functions by controlling the water balance of the body by affecting reabsorption of water by the kidneys. The deficiency of ADH causes diabetes insipid, polyurea, etc.

Q.11. What is Hypothyroidism?

Sol. Hypothyroidism is a hormonal disorder, which is caused by an underactive thyroid gland. In this condition, the thyroid gland does not produce or release enough thyroid hormones or thyroxin required by the body cells.

Causes of Hypothyroidism

Hypothyroidism is quite a common hormonal disorder in today’s world. About 4 to 5 per cent of the population is diagnosed with hypothyroidism. According to the records, women are more prone to this hormonal disorder than men and also it increases along with age. The common causes of hypothyroidism are:

  1. Medications side effects.
  2. Severe iodine deficiency.
  3. Disorder of pituitary gland.
  4. Exposure of neck region to radiations.
  5. Damage or removal of the thyroid gland through surgery.

Symptoms of Hypothyroidism

Depending on the severity of the hormonal deficiency, the signs and symptoms vary from person to person. In some rare cases, this syndrome does not show any symptoms at all.

The most common signs and symptoms of hypothyroidism are:

  1. Fatigue.
  2. Weight gain.
  3. Slow heartbeat.
  4. Decreased libido.
  5. Cold intolerance.
  6. Memory problems.
  7. Decreased breathing.
  8. Coarse and pale skin.
  9. Frequent constipation.
  10. Abnormal menstrual cycles.
  11. High cholesterol in the blood.
  12. Coarse and dry hair with hair loss.
  13. Excessive sleepiness and lack of energy.
  14. Muscle cramps with frequent muscle aches.

Treatment and Precautions for Hypothyroidism

There is no permanent cure but it could be controlled by replacing the level of TSH, T4 and T3 hormones through medications. Few thyroid hormone supplements are available to treat hypothyroidism. The treatment available for this syndrome would be in the form of lifelong therapy.

  1. There are certain safety measures to be followed to control or to reduce the symptoms of hyperparathyroidism:
  2. Quit smoking and consumption of alcohol.
  3. Intake of more water and fresh fruit juice to avoid dehydration.
  4. Regular hormonal level test to detect the functioning of the thyroid gland.
  5. Regular exercise, walking and exercise weight loss programs for managing weight gain.
  6. Having a balanced diet including rich Vitamin D and calcium supplements to avoid the weakness and thinning bones.

Q.12. List out the disorders caused by the irregular secretion of adrenal hormones.

Sol. The disorders caused by the irregular secretion of adrenal hormones are called adrenal gland disorders. This appears when inadequate hormones are produced by the adrenal glands. Even abnormal growths or tumours can cause certain illness.

Addison’s Disease

It is an autoimmune disease where the body mistakenly attacks the adrenal glands. As a result, the adrenal gland does not produce the hormone aldosterone in sufficient quantities. The symptoms include:

  • Loss of appetite.
  • Vomiting
  • Reduced BMR
  • Reduced body temperature.
  • Dehydration.
  • Bronzing of the skin.

Conn’s Disease

It is caused due to the over secretions of mineralocorticoids. The symptoms include:

  • High blood pressure.
  • Malfunctioning of kidneys.
  • A weakness of bones and muscles.

Cushing’s Syndrome

It is caused due to hypersecretion of corticosteroids, which is mainly due to the oversecretion of ACTH – Adrenocorticotropic hormone. The symptoms include:

  • Virilism
  • Oedema
  • hyperglycaemia.

Q.13. Write a note of thyroxine hormone and its disorders.

Sol. Thyroxine hormones are secreted by the thyroid gland. Its functions include:

  • It increases the rate of heartbeat.
  • It increases the activity of the neurosecretion in adrenalin and non-adrenalin.
  • It increases protein synthesis, gluconeogenesis, the body temperature and functions of the nerves.
  • It increases oxidative metabolism, which increases the rate of energy production in our body cells.
  • It increases the absorption of glucose, by the consumption of oxygen in the liver and other basic metabolisms.

Q.14. Which hormones are secreted by ovaries? Describe any two.

Sol. Ovaries are the primary organs of the female reproductive system. They are involved in the secretion of female sex hormones. Ovaries are the follicular cells. In women, the pairs of ovaries activate at an age of 12 to 13 years. This stage is called the beginning of puberty.

The follicular cells under the control of FSH secrete estrogen hormone, which is also called estradiol or feminizing hormone.

The estradiol hormone is an estrogen steroid hormone and the major female sex hormone. Listed below are the functions of estradiol hormone.

  1. It controls oogenesis.
  2. It provides secondary sexual characters.
  3. It controls the menstrual and oestrous cycles.
  4. It stimulates the development of mammary glands.
  5. It controls female sexual accessory organs.
  6. It controls sexual behaviour.
  7. The corpus luteum of the ovaries secrete progesterone under the control of LH hormones.
  8. The progesterone is a steroid hormone, which is also called the pregnancy hormones as it is involved in the preparation of the uterus for embryonic development. The uterine wall becomes more muscular, glandular and vascular.
  9. This hormone also helps in the implantation of the embryo. It inhibits oxytocin and ovulation during pregnancy. In women, the corpus luteum also secretes relaxin hormone at the time of completion of embryonic development.
  10. This hormone helps in parturition by relaxing pubic symphysis.

Q.15. Describe in brief about the adrenal cortex?

Sol. Adrenal Cortex

It is the outermost and light yellow coloured layer of the adrenal gland, which originates from the mesoderm. It weighs about 3 to 4 gm and forms 80 to 85 per cent of the total gland. It functions by producing aldosterone, cortisol, and androgens hormones.

The adrenal cortex is a target organ for Adrenocorticotropic hormone (ACTH), produced in the anterior, or front, the pituitary gland in the brain. They are also called life-saving hormones.

Adrenal cortex comprises of three layers of cortex called zones:

Zona glomerulosa:

  • It is the outer part of the cortex, which consists of small and cuboidal cells.
  • It secretes mineralocorticoids. These hormones are called salt retaining hormones.
  • These hormones maintain a definite quantity of water, Na+ K+ and Cl in the extracellular fluid (ECF). These hormones stimulate the absorption of Na+1 and Cl and excretion of K+ in the kidneys.

Zona fasciculata:

  • It is the middle part of the cortex, which consists of large and polyhedral cells.
  • This part secretes glucocorticoids. Eg. Cortisol, corticosterone, etc.
  • These hormones are used to treat allergy and help in organ transplantation.
  • These hormones act as anti-inflammatory and help in the treatment of arthritis.
  • These hormones stimulate glycogenolysis and gluconeogenesis.

Zona reticularis:

  • It is the inner zone of the cortex, which has cords of polyhedral cells. It also has modified glandular cells.
  • This part secretes androgen, estrogen and progesterone in small quantities. These hormones affect sexual behaviour, hair growth, bone and muscles.
  • The androgen is secreted in the form of di-hydroxy-epi-androsterone.

Q.16. What are the diseases caused by hyposecretion and hypersecretion of the growth hormone?

Sol. Growth hormone is the main stimulator for growth of the body, which promotes the development of bones and muscles, growth of connective tissues and cell division.

The diseases caused by hyposecretion and hypersecretion of the growth hormone are:

Dwarfism

It is caused by the hypersecretion of growth hormone. It is a condition of short stature, an individual with this deficiency syndrome remains dwarf, impotent and infertile. They have normal intellectual development. Due to this, weakness and suppression in reproductive capability is seen in adults. This dwarfism is called ateliosis.

Gigantism

Gigantism is a rare condition that causes abnormal growth in children by the overproduction of Growth Hormone by the pituitary gland. Common symptoms of gigantism include very large hands and feet, weakness, coarse facial features, sleep disorders, thick toes and fingers, a prominent jaw and forehead, etc. Generally, the treatment for this disorder includes radiation therapy and surgery for the removal of the tumour cells and few medications to shrink the tumour cells or to stop the production of excess growth hormone.

Acromegaly

It is the most common disorder caused by the overproduction of Growth Hormone by the pituitary gland. Due to the excessive growth of this gland, the surrounding nerve tissues and optic nerves get compressed. This results in the growth of the bone and the enlargement of organs. People suffering from this disease have much larger bones when compared to other people. It is estimated that about 95% of the people affected by this disease have a tumour which affects the pituitary gland. There is a wide range of symptoms, including sleeplessness, fatigue, frequent sweating, abnormal weight gain, etc. Acromegaly is mostly found in the adults, between the age of 30 to 50, but there are chances of getting the symptoms at any age. Generally, the treatment for this disorder varies with the patient’s age, health, and how far the condition is. Radiation therapy and surgery for the removal of the tumour cells are the only available treatments for acromegaly

Q.17. Draw a neat labelled diagram of an endocrine system and list out the different hormones with respective glands in humans.

Sol. The Endocrine System.

The Endocrine System

List out the different hormones with respective glands in humans.

Endocrine glands Functions
Hypothalamus Gland Antidiuretic hormone
Pituitary Gland Growth hormone
Thyroid Gland Thyroxine
Pancreas Gland Insulin and Glucagon
Adrenal Gland Epinephrine
Testes Gland Testosterone
Ovaries Gland Estrogen and Progesterone

Q.18. What are gonad glands?

Sol. Gonads are the female and male reproductive organs. Testes are the male gonads in males and ovaries in females. These organs of reproductive organs are essential for sexual reproduction since they are responsible for the production of male and female gametes. Gonads are also responsible for producing sex hormones required for the development and growth of primary and secondary reproductive structures organs.

Functions of Gonads glands.

Gonads are the components of the Endocrine system, which functions by producing both male and female sex hormones. Hormones that are responsible for stimulating the gonads to produce sex hormones are called gonadotropins.

Female Gonadal Hormones

The major hormones of the ovaries are progesterone and estrogens.

Estrogens

  • It is a group of female sex hormones essential for reproduction and the development of the female reproductive system.
  • It plays a major role in the menstrual cycle and growth of the vagina and uterus.
  • It is also involved in the development of secondary sexual characteristics in females by widening of pelvis, breast and increasing growth of hair on the body.

Progesterone

  • These hormones function by preparing the uterus for conception
  • It regulates the changes in the uterus during the menstrual cycle and ovulation.
  • It stimulates the mammary glands for development and the production of milk during pregnancy.

Male Gonadal Hormones

  • Androgens are hormones that influence the development of the male reproductive system.
  • Testosterone is responsible and essential for increased bone and muscle, growth of body hair, developing broader shoulder, voice deepening and growth of the penis.
  • Androstenedione hormones act as a precursor to estrogens and testosterone.
  • Inhibin hormones inhibit the release of FSH and are involved in sperm cell regulation and development.

Q.19. What are glands? How many glands are in the human body?

Sol. Glands are the essential organs of the human body, which are located throughout the body. They function by producing and releasing chemical substances that perform certain important functions.

The human body comprises three different types of glands:

Exocrine glands

These glands deliver their secretions in various body parts through the respective ducts. Therefore, the exocrine glands are called the glands with the duct. These glands secrete enzymes including salivary glands, sebaceous glands, mammary glands, pancreas and liver.

Endocrine glands

These glands are ductless, which lack ducts. They deliver their secretions into various body parts through the blood cells. Endocrine glands secrete hormones and are transported to the target through the blood. The thyroid gland, pineal gland, thalamus gland, pituitary gland, liver, pancreas, ovaries, testes are examples of endocrine glands.

Mixed glands

These glands comprise both endocrine and exocrine glands. The mixed glands are glands with the duct and carry functions of both serous and mucous secretory units. The pancreas is known as a mixed gland because it performs functions of both exocrine and endocrine glands .i.e. by secreting both hormones and digestive enzymes.

Q.20. Write a note of hyperthyroidism and its disorders.

Sol.

Hyperthyroidism is a hormonal disorder. Around 1.2 per cent of people in the United States have an overactive thyroid gland. This condition is caused when the thyroid gland produces too much thyroid hormones, namely T3, T4 and thyroxine. According to the records, women are more prone to this hormonal disorder than men and it also increases with age.

Hyperthyroidism Symptoms

Hyperthyroidism is caused by an overproduction of T3, T4 and thyroxine hormone by the thyroid gland. The common characteristic symptoms of hyperthyroidism include:

  1. Fatigue.
  2. Irritability.
  3. Nervousness.
  4. Difficulty sleeping.
  5. Changes in appetite.
  6. Unexpected weight loss
  7. Rapid or irregular heartbeat
  8. A tremor in the fingers and hands.
  9. Increased sweating and heat intolerance.
  10. An enlarged thyroid, in the form of swelling in the neck.

Treatment for Hyperthyroidism

Treatments include radioactive iodine, medications in the form of antithyroid agents, or surgery as a last resort. There is no complete cure for the hormonal disorder, but there are many medications available to control the synthesis of hormones by the respective endocrine glands and other symptoms.

We, at BYJU’S, aim to deliver students with all the necessary support and allow them to prove their abilities by performing very well in their examination. Important Questions for RBSE Class 12 Biology Chapter 29 – Chemical Coordination in Humans are prepared by a team of subject experts under the guidance of RBSE syllabus for Class 12

Stay tuned with BYJU’S for more detailed information regarding the RBSE Class 12 Biology chapter wise important questions and other related topics.

Leave a Comment

Your email address will not be published. Required fields are marked *

BOOK

Free Class

by India's top teacher with
live doubt solving