The Endocrine System

A is True and R is False.

Explanation
Hormones are directly poured into the blood. The blood transports it to the target organ.

Both A and R are False.

Explanation
Adrenal cortex secretes glucocorticoids which regulate glucose levels of the blood. Glucocorticoids help regulate blood glucose levels by promoting gluconeogenesis.

A is False and R is True

Explanation
Under-secretion of insulin causes hyperglycemia or diabetes mellitus.

A is False and R is True.

Explanation
Cretinism is a condition which affects children causing dwarfism and mental retardation. The thyroid gland degenerates in early childhood.

(a) Endocrine system — Endocrine system consists of several endocrine glands/glandular cells which activate each other and work as a system to bring about overall chemical coordination in the body.

(b) Hormones — Hormone is a secretion from some glandular part of the body, which is poured directly into blood and which acts on the target organs or cells of the same individual, bringing about coordination between distant parts of the body.

(c) Myxoedema — Myxoedema is a condition which occurs in adults due to hypothyroidism in which the person becomes sluggish with swelling of the face and hands.

(a) Difference between exocrine and endocrine glands (secretory substance and example):

(b) Difference between enzymes and hormones (mode of transport and target organ):

(c) Difference between nervous control and hormonal control (transmission and effect):

(d) Difference between diabetes mellitus and diabetes insipidus (cause and symptoms):

(e) Difference between Addison's disease and Cushing's syndrome (cause and sugar level):

(a) Adrenaline is known as the Emergency hormone because it prepares the body to meet any emergency situation, for "fight" i.e. to face danger or for "flight" i.e. to run away from it. Extra energy and strength is provided to the body in that situation. It stimulates the sympathetic nervous system. When excited or angry, the adrenal medulla produces a lot of Adrenaline preparing the body for any emergency.

(b) Pituitary is popularly called as the master gland because it controls the functioning of all the other endocrine glands.

(c) People living in the low Himalayan hilly regions often suffer from goitre because iodine is deficient in the soil of those regions and hence, in the food grown there. Insufficient iodine produces less thyroxine which results in goitre.

(d) Iodised salt contains iodine which is an active ingredient in the production of thyroxine. Hence, it is recommended to use iodised salt in food to prevent simple goitre.

(a) Adrenal

(b) Pancreas

(c) Thyroid

(d) Pituitary

Sebaceous gland

Reason — Sebaceous gland is present in skin and secretes oily sebum.

Prolactin

Reason — Prolactin is responsible for formation and secretion of milk.

Uterus

Reason — Oxytocin stimulates the contraction of uterus during child birth.

Gigantism and Acromegaly

Reason — Hypersecretion of growth hormone in young age causes gigantism while in adults it causes acromegaly.

Pancreas

Reason — Pancreas secretes digestive juices as well as hormones like insulin and glucagon.

β-cells of Pancreas

Reason — β-cells of islet of Langerhans in Pancreas secrete insulin.

Pancreas

Reason — Islets of Langerhans are small group of cells present in pancreas.

Thyroid

Reason — Over activity of thyroid leads to over secretion of thyroxine which further results in exophthalmic goitre.

Adrenaline

Reason — Adrenaline causes stimulation of sympathetic nervous system and prepares body for any emergency.

Glucagon

Reason — Glucagon is responsible for breakdown of glycogen in the liver to glucose. It increases the level of glucose in blood.

P - Insulin, Q - Vasopressin

Reason

The function of insulin is to regulate blood sugar levels and its hyposecretion causes diabetes mellitus (high blood sugar). The function of vasopressin is to help kidney in reabsorption of water and its hyposecretion causes diabetes insipidus.

(i) Regulation of activities inside the body are brought about by nervous and endocrine systems.

(ii) Hormones are secreted directly into the blood.

(iii) Chemically, some hormones are proteins, some steroids, some amines.

(iv) Both excess or deficiency of hormones lead to serious consequences.

(v) Hormones produced in one species usually show similar influence in other species.

(i) Site of action for hormones is their target organ or cells.

(ii) Hormones are either protein, amines or steroids.

(iii) Hormones are poured into blood by the glands and are transported through blood.

The three types of cells of islets of Langerhans and hormones secreted by them are:

1. Beta cells — insulin
2. Alpha cells — glucagon
3. Delta cells — somatostatin

1. It promotes glucose utilisation by the body cells, thereby reducing the blood sugar level.
2. It stimulates deposition of extra glucose of the blood as glycogen in liver and muscles.

(i) Diabetes mellitus

(ii) Insulin Shock

Three symptoms of diabetes mellitus are:

1. High concentration of sugar in blood.
2. Excretion of more urine loaded with sugar.
3. Increased thirst due to loss of water through too much urination.

1. Glucocorticoids.
2. Sex corticoids.

Two effects of adrenaline are:

1. Thumping heart
2. Dry mouth

(i) Thyroid is located close to larynx.

(ii) Cretinism is caused due to undersecretion of thyroxin.

(iii) Over-secretion of thyroxin causes exophthalmic goitre.

(iv) The condition showing swelling in face and hands and sluggishness due to hypothyroidism is called myxoedema.

(v) The hormone concerned with facing dangers is adrenaline.

(vi) Cortex and medulla are the two regions adrenal.

(vii) One of the effects of increased secretion of adrenaline is Dry mouth.

(i) False
Corrected Statement — Pituitary is of the size of a pea.

(ii) True

(iii) True

(iv) False
Corrected Statement — Vasopressin secreted by posterior lobe controls reabsorption of water form kidney tubules.

(i) TSH — Thyroid Stimulating Hormone

(ii) LH — Luteinizing Hormone

(iii) ACTH — Adrenocorticotropic Hormone

(iv) ADH — Antidiuretic Hormone

(i) Oversecretion of growth hormone in adults causes acromegaly.

(ii) Deficiency of ADH causes diabetes insipidus.

(a) Hyperglycemia

(b) Simple goitre

(c) Cretinism

(d) Exophthalmic goitre

(e) Acromegaly in adults and gigantism in children.

(a) Thyroid — It is situated in the front part of the neck just below the larynx.

(b) Adrenal — It is present as a cap on the top of each kidney.

(c) Pancreas — It is located behind the stomach in the upper left abdomen.

(d) Pituitary — It hangs from the base of the mid-brain below the hypothalamus.

(a) Three hormones secreted from islets of Langerhans of pancreas are —

1. Insulin
2. Glucagon
3. Somatostatin

(b) Two types of cortical hormones are —

1. Glucocorticoids
2. Mineralocorticoids

(c) Six hormones secreted from anterior pituitary are —

1. Growth hormone (somatostatin)
2. Prolactin
3. Adreno-corticotropic hormone (ACTH)
4. Thyroid stimulating hormone (TSH)
5. Follicle stimulating hormone (FSH)
6. Luteinizing hormone (LH)

(d) Two hormones secreted from posterior pituitary are —

1. Antidiuretic hormone (ADH) or Vasopressin
2. Oxytocin

(e) The emergency hormone is —

1. Adrenaline

(f) Diseases caused due to hypothyroidism —

1. Simple goitre
2. Cretinism
3. Myxoedema

(g) Symptoms of cretinism —

1. Mental retardation
2. Dwarfism

(h) Abnormalities caused due to hypersecretion of growth hormone

1. Gigantism
2. Acromegaly

When we stand to make our maiden speech before a large audience, our mouth dries up and heart rate increases and it is due to secretion of adrenaline hormone by adrenal glands. Adrenaline is the hormone which prepares the body to meet any emergency situation. Adrenaline makes the heart beat faster. At the same time, it stimulates the constriction of the arterioles of the digestive system reducing the blood supply of the digestive system which makes the mouth dry.

(a) Glucagon is produced by the Alpha cells of the islets of Langerhans.
Insulin is produced by the Beta cells of the islets of Langerhans.

(b) The main function of Glucagon is to raise the blood glucose levels by stimulating the breakdown of glycogen to glucose in the liver.
The main function of Insulin is to maintain the levels of glucose (sugar) in the blood.

(c) Exocrine glands are those glands which deliver their secretions to the target through ducts. An endocrine gland is one which does not pour its secretions into a duct but directly into the blood. As an exocrine gland the pancreas secrete pancreatic juices into the duodenum for digestion. As an endocrine gland, it has special groups of hormone-secreting cells called Islets of Langerhans which are scattered in the entire gland. The islet cells produce three hormones — insulin, glucagon and somatostatin which are poured directly into the blood. Hence, the pancreas is an exo-endocrine gland.

(d) Insulin is not administered orally because the digestive juices degrade insulin making it ineffective. Hence, to avoid its degradation, Insulin is injected into the body.

(e) Islets of Langerhans

(f) The Pancreas is located in the abdomen behind the stomach.

(a) This portion is located in the neck region above the sternum.

(b) The structures numbered 1-3 are:

• 1 → Larynx
• 2 → Thyroid gland
• 3 → Trachea

(c) One main function of each of these structures is:

1. Larynx is the voice box containing vocal cords. It helps in producing sound.
2. Thyroid gland produces thyroxine and calcitonin which are essential hormones.
3. Trachea is the wind pipe that helps in passing air to and from the respiratory system while breathing.

(d) Structure 2 is the thyroid gland. It is an endocrine gland, so it is ductless and pours its secretions directly into the blood. Hence, there is no duct.

(a) The parts numbered 1-4 are:

• 1 → Pituitary gland
• 2 → Thyroid gland
• 3 → Pancreas
• 4 → Adrenal Glands

(b) All the glands shown in the above diagram are endocrine glands. They secrete essential hormones and pour their secretions directly into the blood.

(c) Iodine is essential for the normal working of Thyroid gland.

(a) The gland shown is Pituitary gland. It hangs from the base of the mid-brain below the hypothalamus.

(b)

• 1 → Anterior lobe
• 2 → Posterior lobe
• 3 → Hypophysial stalk

(c) Two secretions from part 1 are Growth hormone and Thyroid Stimulating Hormone.

Two secretions from part 2 are ADH and Oxytocin

(d) The deficiency of ADH causes Diabetes insipidus. Urine does not contain any glucose in this condition but in Diabetes mellitus there is glucose present in the urine.

(a) C

(b) Gigantism

(c) Anterior lobe of pitutary gland

(a) Adrenaline

(b) Hypoglycemia

(c) Insulin

(d) Isthmus

(e) Anti-diuretic hormone (Vasopressin)

(f) Adrenaline

If there was hyposecretion of the thyroid gland in a child, the child will suffer from cretinism. The symptoms of cretinism are dwarfism, mental retardation, etc.

(a) Odd term: Pellagra
Category: Diseases caused due to hypothyroidism

(b) Odd term: Gamma cells
Category: Islet of Langerhans

(c) Odd term: Oxytocin
Category: Hormones secreted by anterior part of pituitary gland

(d) Odd term: Prostate
Category: Endocrine glands

(e) Odd term: Thiamine (It is a vitamin)
Category: Hormones

(a) ACTH — Adrenocorticotropic Hormone

(b) TSH — Thyroid Stimulating Hormone

(c) ADH — Antidiuretic Hormone

(d) LH — Luteinizing Hormone

(e) FSH — Follicle Stimulating Hormone

(a) Larynx is the odd one here because glucagon; testosterone and prolactin are hormones whereas Larynx is the sound box.

(b) Penicillin is the odd one here because adrenaline; insulin; thyroxine are hormones whereas Penicillin is an antibiotic.

(c) Adrenaline is the odd one here because stomach, ileum and liver are the organs of the digestive system whereas Adrenaline is a hormone.

(d) Insulin is the odd one here because TSH, GH, ADH are the hormones secreted by the pituitary gland whereas Insulin is secreted by the pancreas.

(e) Iodine is the odd one here because cretinism, goitre, myxoedema are the conditions which occur due to undersecretion of thyroxine (Hypothyroidism) whereas Iodine is required for the synthesis of thyroxine hormone.

(a) Beta cells : Insulin :: Alpha cells : Glucagon.

(b) Children : Cretinism :: Adults : Myxoedema.

(c) Undersecretion : Dwarfism :: Oversecretion : Gigantism.

(d) Diabetes mellitus : Insulin :: Diabetes insipidus : Antidiuretic hormone (ADH).