Human anatomy and physiology Endocrine system. Hormones

1. ENDOCRINE SYSTEM
PREPARED BY
MISS.RUBI S.KHAN
(PRINCIPAL)
DNYANDEEP COLLEGE OF PHARMACY SHITALWADI
RAMTEK
D- PHARM-I
E.R. 20

2. INTORDUCTION
The endocrine sytem is the collection of glands that secrete the hormones and
neurotransmitter in the body .
It regulate the body physiology and major participate in the defensive
mechanism of the body.
The major endocrine glands include,
 Pineal gland
Pituitary gland
Pancreas
Ovaries
Testes
Thyroidgland
Parathyroid gland
Hypothalamus
Gastrointestinal tract
Adrenal gland

3. FUNCTION OF ENDOCRINE SYSTEM
1. The main function of your endocrine system is to release hormones
into your blood while continuously monitoring the levels.
2. Hormones regulate the metabolism processes of the body
3. Growth and development.
4. Sexual function.
5. Reproduction.
6. Sleep-wake cycle.
7. Mood.

4. Difference Between Exocrine Glands and Endocrine Glands
Endocrine Glands Exocrine Glands
Ducts
Endocrine glands do not have ducts. Exocrine glands have ducts.
Secretory Products
Hormones Sweat, enzymes, mucus, sebum
Route of Secretion
Secretory products are released
directly into the bloodstream,
eventually reaching the target organ.
Secretory products are released to an
internal organ or the external surface
through a duct.
Examples
Thyroid glands, parathyroid glands,
pituitary glands, adrenal glands.
Salivary glands, liver, Brunner’s
glands, oesophageal glands.

5. MAJOR
ENDOCRINE
GLAND

6. The branch of science that deals with the study of structure and function of
endocrine gland, their disorders and their treatments is called as
ENDOCRINOLOGY.
HORMONES
Hormones are mediator molecules that are released in one part of the body but
regulate the activity of the cells in other parts of the body.
Hormones regulate important body processes and functions including growth,
reproduction and metabolism.
There are two types of the hormones,
1. Local hormons.
2. Circulating hormones.

7. FUNCTION OF HORMONES
1. Control growth and development.
2. Regulate chemical composition and volume of the internal environment
3. Regulate metabolism
4. Regulate secretions
5. Maintain immune system
6. Regulate operation of reproductive system.

8. PITUITARY GLAND AND HYPOTHALAMUS
Pituitary gland is a small endocrine gland located in a depression called ‘sella
turcica’ present in the sphenoid bone at the base of skull.
Pituitary gland is divided into two divisions,
1.Anterior pituitary or adenohypophysis
2.Posterior pituitary or neurohypophysis
1.Anterior pituitary or adenohypophysis
It secretes many hormones and regulates the
other endocrine gland’s function, so it is also known as master gland.
Adenohypophysis consists of two portions, pars distalis and pars intermedia.

9. Anterior pituitary /adenohypophysis produces,
1. Growth/somatotropic hormone (GH/STH)- GH is responsible for the general
growth of the body.
2. Thyroid stimulating hormone (TSH)- TSH stimulates the synthesis and
secretion of thyroid hormones from the thyroid gland.
3. Adrenocorticotropic hormone (ACTH)- ACTH stimulates the synthesis and
secretion of steroid hormones called glucocorticoids from the adrenal cortex.
4. Prolactin (PRL)- Prolactin regulates the growth of the mammary glands and
formation of milk in them
5. Follicle stimulating hormone (FSH)- In males, FSH and androgens regulate
spermatogenesis. . FSH stimulates growth and development of the ovarian
follicles in females
6. Luteinizing hormone (LH)-In males, LH stimulates the synthesis and
secretion of hormones called androgens from testis. In females, LH induces
ovulation of fully mature follicles and maintains the ovulation

10. posterior pituitary or
neurohypophysis produces,
1. Oxytocin- Oxytocin acts on the smooth
muscles of our body and stimulates their
contraction. In females, it stimulates a
vigorous contraction of uterus at the time
of child birth, and milk ejection from the
mammary gland.
2. Vasopressin- Vasopressin acts mainly at
the kidney and resorption of water and
electrolytes by the distal tubules and
thereby reduces loss of water through
urine
Pituitary gland

11. ADRENAL GLAND
Our body has one pair of adrenal glands, one at the anterior part of each
kidney. The gland is composed of two types of tissues. The centrally located
tissue is called the adrenal medulla, and outside this lies the adrenal cortex.
Adrenal medulla— Adrenal medullary hormones are the amines
derived from catechol and so these hormones are called catecholamines.
1. Adrenaline or epinephrine.
2. Noradrenaline or norepinephrine.
3. Dopamine.
Adrenaline and noradrenaline are rapidly secreted .
In response to stress of any kind and during emergency
situations and are called emergency hormones or hormones
of Fight or Flight. These hormones increase alertness, pupillary dilation,
heartbeat

12. piloerection (raising of hairs), sweating etc. Both the hormones increase the, the
strength of heart contraction and the rate of respiration.
Adrenal cortex- 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,
commonly called as corticoids.
1. Mineralocorticoids- Play critical role in maintaining the electrolyte and
fluid balance of the body.
2. Aldosterone- regulate homeostasis of sodium and potassium ion and helps to
regulating blood pressure and blood volume.
3. Glucocorticoids- helps to responds to environmental change, have anti
inflammatory property.

13. THYROID AND PARATHYROID GLAND
1. Thyroid gland situated at the roof of the neck on either side of the trachea.
2. It weight approximately 30g.
3. It is butterfly shaped, having two lobes and both the lobes are interconnected
with a thin flap of connective tissue called isthmus.
4. The gland is made of a large number of follicles called thyroid follicles.
5. These follicular cells synthesise two hormones, tetraiodothyronine or
thyroxin (T4) having 4 atom of iodine and triiodothyronine (T3) having 3
atom of iodine.
6. T3 and T4 are called as thyroid hormones.
7. In between the follicles, the parafollicular cells are present. These cells
secrete calcitonin.
8. Iodine is essential for the normal rate of hormone synthesis in the thyroid.

14. FUNCTIONS OF THYROID HORMONE
 Thyroid hormones play an important
role in the regulation of the basal
metabolic rate.
It also supports the process of red blood
cell formation.
 Thyroid hormones control the metabolism
of carbohydrates, proteins and fats.
 Maintenance of water and electrolyte balance
is also influenced by thyroid hormones.
 Thyroid gland also secretes a protein hormone
called thyrocalcitonin (TCT) which regulates
the blood calcium levels.

15. DISORDER RELATED TO THYROID GLAND
Hyperthyroidism— Increased secretion of thyroid hormone is called
hyperthyroidism.
Hypothyroidism— decreased secretion of thyroid hormone is called
hypothyroidism.
Goitre— Goitre means enlargement of thyroid gland. It occurs both in
hypothyroidism and hyperthyroidism.
PARATHYROID GLAND
In humans, four parathyroid glands are present on the back side of the
thyroid gland.
one pair each in the two lobes of the thyroid gland.
Each parathyroid gland is made up of chief cells, which secrete a peptide
hormone called parathyroid hormone (PTH)/parathormone.
The secretion of PTH is regulated by the circulating levels of calcium
ions.

16. FUNCTIONS OF PARATHYROID HORMONE
Parathyroid hormone (PTH) increases
the Ca2+ levels in the blood.
PTH acts on bones and stimulates the
process of bone resorption dissolution.
PTH also stimulates reabsorption of Ca2+
by the renal tubules and increases Ca2+
absorption from the digested food.
It is, thus, clear that PTH is a
hypercalcaemic hormone, i.e., it increases
the blood Ca2+ levels.

17. THYROID GLAND PARATHYROID GLAND

18. DISORDER RELATED TO PARATHYROID GLAND
Hypoparathyroidism— less secretion of PTH is called hypoparathyroidism.
It leads to hypocalcaemia (decrease in blood calcium level)
Hyperparathyroidism— Hyper secretion of PTH is called
hyperparathyroidism. It leads in hypercalcemia (Increase in blood
calcium level).
PANCREAS
Pancreas is a composite gland which acts as both exocrine and endocrine gland.
It measures about 12.5-15cm in length.
It consist of a head, body and a tail.
The endocrine pancreas consists of ‘Islets of Langerhans’.

19. The two main types of cells in the Islet of Langerhans are called α-cells and β-
cells. The α-cells secrete a hormone called glucagon, while the β-cells secrete
insulin.
Glucagon
Glucagon is a peptide hormone, and plays an important role in
maintaining the normal blood glucose levels.
Glucagon acts mainly on the liver cells (hepatocytes) and stimulates
glycogenolysis resulting in an increased blood sugar (hyperglycaemia).
 Glucagon reduces the cellular glucose uptake and utilisation. Thus,
glucagon is a hyperglycaemic hormone.

20. Insulin
 Insulin is a peptide hormone, which plays a major role in the regulation of
glucose homeostasis.
Insulin acts mainly on hepatocytes and adipocytes and enhances cellular
glucose uptake and utilisation. As a result, there is a rapid movement of
glucose from blood to hepatocytes and adipocytes resulting in decreased
blood glucose levels (hypoglycaemia).
Insulin also stimulates conversion of glucose to glycogen (glycogenesis) in
the target cells.
Somatostatin
It is secreated by the delta cells of pancreatic islets. It inhibit the secretion of
pancreatic polypeptide.

21. GONADS (TESTES AND OVARIES)
In gonads we discuss about both testis and ovary.
Gonads are the organs that produce gametes-sperm in males and oocytes in
females.
OVARY
The ovaries are paired oval bodies located in the female pelvic cavity,
produce steroid hormones including estrogen and progestrone.
Function of estrogen and progestrone.
 The female sex hormones, along with FSH and LH from anterior
pituitary,
1. regulate the menstrual cycle.
2. maintain pregnancy.
3. prepare mammary glands for lactation.
4. Promote enlargement of the breast.
5. Promote widening of hip at puberty.

22. TESTES
•Oval glands lie in the scrotum.The main hormone produced and secreted by the
testes is testosteron.
Function of testosteron
1. Stimulate production of sperm.
2. Growth of beard and deepening of the voice.
3. growth of facial and axillary hair, aggressiveness.
4. These hormones produce anabolic (synthetic) effects on protein and
carbohydrate metabolism.

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