|Table of contents|
|Hormones in Animals|
|Difference between Nervous and Hormonal Coordination|
|Some Important Endocrine Glands and Hormones|
Pancreas has both exocrine and endocrine part, so it is also called mixed gland or common gland or heterocrine gland.
- These glands lack ducts, so they are called ductless glands.
- Examples of endocrine glands include the thyroid gland and parathyroid gland.
- The thyroid gland secretes hormones that regulate metabolism, growth, and development.
- Sweat glands and salivary glands, on the other hand, are examples of exocrine glands.
- Exocrine glands have ducts through which they release their secretions.
- The pancreas is a mixed gland that has both exocrine and endocrine functions.
- It secretes digestive enzymes through its ducts, but it also releases hormones, such as insulin and glucagon, into the bloodstream.
- Therefore, the correct answer is Option A: Thyroid gland, as it is an example of an endocrine gland.
Major Endocrine Glands
|S. NO.||Nervous Coordination||Hormonal Coordination|
|1||It is sent as an electrical impulse along axons, and as a chemical across synapse.||It is sent as a chemical messenger via blood stream.|
|2||Information travels rapidly, in milliseconds.||Information travels slowly.|
|3||Information is directed to specific receptors–one or a few nerve fibres, gland cells or other neurons.||Information is spread throughout the body by blood from which the target cells or organs pick it up.|
|4||It gets response immediately.||It gets response usually slowly.|
|5||Its effects are short-lived.||Its effects are generally more prolonged.|
|S. No.||Nature of Endocrine gland||Position in body||Hormone(s)||Chemical Nature of Hormones||Function(s)||Hypo/Hypersection Causes||Special Points|
|1||Hypothalamus||Below thalamus in brain||Releasing and inhibiting hormones||Protein||Regulate the release of pituitary hormones||Ectodermal in orgin|
- Anterior gland
Below hypothalamus attached to it with a stalk called infundibulum
|GH (Growth Hormone)||Protein|
Hyposecretion in children causes dwarfism
|Also called master gland of the body|
|Growth of Muscles and bones||Hypersecretion in children causes gigantism and in adults causes acromegaly|
|TSH (Thyroid Stimulating Hormone)||Protein||Regulate the secretion of hormones from thyroid|
|ACTH (Adreno Cortico Tropic Hormone)||Protein||Secretion of hormones from adrenal cortex|
|FSH (Follicle Stimulating Hormone)||Protein||stimulate spermatogenesis and oogenesis|
|LH (Luteinising Hormone)||Protein||It causes ovulatiin and formation of corpus luteum|
- LH in males is called ICSH
|LTH (Luteotropic Honnone)||Protein|
Stimulate growth of mammary glands during pregnancy and promotes lactation alter parturition (delivery)
- Also Known as Prolactin.
Metachrosis (colour change) in poikilothermals (cold blooded animals)
- In human MSH is secreted by anterior lobe is merged in anterior lobe
-Function in human is not known.
- Contraction of uterine muscles during pregnancy
- Causes release of milk after delivery
Also called birth hormone
- Reabsorption of water from DCT of nephron and collecting duct
-Hyposecretion causes Diabetes insipidus
Also called ADH (Antidiuretic hormone)
|3||Thyroid||Located in the neck between the trachea and larynx||Thyroxine||Amine||Regulate BMR of body||- Hyposecretion in children causes cretinism||Thyroxine is the only hormone stored in our body|
-Decreases the level of calcium in blood
- Hyposecretion in adults causes myxoedema
- Generally say hyposecretion of thyroxine causes simple goitre
- Hypersecretion of Thyroxine causes exophthalmic goitre
Element in thyroxine is iodine
|4||Parathyroid||Attached to thyroid|
Increases the level of calcium in blood
Hypersecretion of PTH causes osteoporosis
Hyposecretion causes tetany
|Also called Collip's Hormone|
|5||Pineal gland||Attached to epithalamus in brain||Melatonin||Amine|
- Metachrosis in poikibthermals
- Control sexual behaviour in mammals
- Also called epiphysis cerebri
- Also called as third eye in frog
- Ectodermal in origin
|6||Pancreas||In the loop of duodenum|
- Decreases the level of glucose in blood
|- Hyposecretion of insulin causes Diabetes mellitus|
World Diabetes Day 14 November
|- Glucagon||- Protein||- Increases the level of glucose in blood|
- Endocrine part of pancreas is called Islets of Langerhans.
- Endodennal in origin
|7||Adrenal Gland||Above Kidney|
Hyposecretion of corticoids causes Addison's disease
Ectomesodennal in origin
Maintain the level of Na+, K+ and Cl- body
Hypersecretion of corticoids causes Cushing's and Conn's disease
|Also called 3-F gland, Life saving gland, 4-S gland, Emergency gland|
|Gluco corticoids||Carbohydrate metabolism|
|Sex corticoids||Secrete androgens and estrogens|
|Adrenaline||Amine||Increases heart beat, blood pressure and blood glucose level|
|8||Testes||Outside the abdominal cavity||Testosterone||Steroid|
-Promote secondary sexual
|9||Ovaries||Inside the abdominal cavity||Estrogen||Steroid||Stimuate oogenesis|
- Promote secondary sexual characters in females
|- Maintain pregnancy||Progesterone is also called anti abortion hormone|
|10||Thymus||Near Heart||Thymosin||Protein||Increase immunity of body|
- Endodermal in origin
-Also called Throne of Immunity or training School of T-lymphocytes
|1. What are hormones?|
|2. How are nervous and hormonal coordination different?|
|3. What are some important endocrine glands and hormones in animals?|
|4. How does the endocrine system regulate the body?|
|5. What are some examples of hormonal disorders in animals?|