2. ENDOCRINE SYSTEM
Endocrine system helps in the regulation and
coordination of body and body activities .
The endocrine system and nervous system work
together.

4. HORMONES
Reacting to fear, growing taller, and developing male or
female characteristics are all activities in the body that
are partially regulated by hormones.
Hormones are substances secreted (released) by cells
that act to regulate the activity of other cells in the
body.
Hormones act as chemical messengers, carrying
instructions that cause cells to change their activities.
Hormones act on a specific tissue called target tissue.

5. The processes in the body that
are regulated by hormones
include:
Overall metabolism
Maintenance of homeostasis
Growth
Reproduction
Behavior

6. GLANDS
Glands are organs of endocrine system specialized
for secretion of substances like hormones.
Some glands secrete their secretions into some
organs by ducts, they are called EXOCRINE
GLANDS.
Other glands release their secretion directly into
the bloodstream that called ENDOCRINE GLANDS.
Some glands secrete their secretions both into
bloodstream and body organs, they are called as
MIXED GLANDS

7. Types of hormones
Proteinic Hormones consist of chain
of amino acids or related compounds.

Steroid Hormones are lipid like,
carbon ring compounds that are
chemically similar to cholesterol and
bile.

10. Regulation of hormone
secretion
The rate of hormone secretion varies with the needs
of the body.
In many cases the level of a hormone in the blood
turns production of the hormone off and on through
feedback mechanisms.
If high levels of a hormone stimulate the output of
even more hormone, the regulation is called positive
feedback.
In negative feedback, the production of some
hormone or substance stops the production of another
hormone.

11. Negative feedback

13. HUMAN
ENDOCRINE
GLANDS
Pineal
Hypothalamus
Pituitary
Thyroid
Parathyoid
Thymus
Adrenal
Pancreas
Ovaries
Testes

15. HYPOTHALAMUS
 The hypothalamus is the area of the brain
that coordinates the activities of the
nervous and endocrine systems. It
controls many body functions, including
body temperature, blood pressure, and
emotions.
The hypothalamus receives information
about external and internal conditions
from other brain regions. The
hypothalamus responds by giving
instructions—in the form of hormones—to
the pituitary gland.

17. Hormones of Hypothalamus
Growth Hormone Releasing Hormone
(GRH or GH)
Adrenocorticotropic Hormone Releasing
Hormone (CRH or ACTH)
Thyroid Releasing Hormone (TRH or TSH)
Gonadotropic Releasing Hormone GnRH
(LH – FSH – LTH – RH)

18. PITUITARY GLAND
The pituitary gland is an endocrine gland suspended
from the hypothalamus by a short stalk.
The pituitary gland secretes many hormones, including
some that control endocrine glands elsewhere in the
body.
Hormones:
Tropic Hormones
 Growth Hormone
 MSH (Melanin Stimulating Hormone)
ADH (Antiduretic Hormone)
Oxytocin


20. Tropic Hormones
These hormones stimulate the secretions of
other hormones
Thyroid Stimulating Hormone (TSH): Thyroid
Gland
Adrenocorticotropic Hormone (ACTH): adrenal
glands
Gonadotropic Hormones (LH, FSH, GTH): glands
of the reproductive system.
Follicle Stimulating Hormone (FSH): Growth and
maturation of the egg in the follicle.
In the testes, it stimulates the production of
sperm.

21. Growth Hormone
Other name SOMATOTROPIN
A deficiency in this hormone will
result in a condition known as
DWARFISM.
An excess amount of this hormone
causes an abnormal increase in the
length. This condition is known as
GIGANTISM.

22. MSH (Melanin Stimulating Hormone) It
stimulates production of melanocytes
MSH determines the color of the skin.
ADH (Vasopressin): Its main function is to
regulate the water balance of the body by
controlling reabsorption of water in the kidneys.
OXYTOCIN: This hormone stimulates the
smooth muscle fibers of the uterus to contract
during labor.
It causes contractions of the channel cells of
the mammary glands so that milk can be
secreted.

23. Thyroid and parathyroid gland
The thyroid gland,
located in the neck, is
wrapped around the
trachea.
The parathyroid glands
are located on the back
of the thyroid gland.

24. Hormones
Thyroid hormone thyroxin which has iodine in
its structure
Thyroid hormones regulate the body’s
metabolic rate and promote normal growth of
the brain, bones, and muscles during childhood.
Thyroid hormones also affect reproductive
functions and maintain mental alertness in
adults.

25. A high level of calcium in the blood stimulates the
thyroid gland to produce a hormone called
calcitonin. Calcitonin causes calcium to be
deposited in bone tissue rapidly, lowering the
blood-calcium level.
Parathyroid hormone (PTH) or parathormone
released by parathyroid gland.
PTH is made and released in response to a falling
level of calcium in the blood in order to increase it.

26. Thyroid gland disorders
 The underproduction of thyroid hormones is hypothyroidism.
 The overproduction of thyroid hormones is hyperthyroidism.

28. Pancreas

29. Pancreas
The pancreas contains clusters of specialized cells,
called the islets of Langerhans. Two hormones made by
the islet cells that interact to control the level of
glucose in the blood.
Insulin, produced by β cells, is a hormone that
lowers blood glucose level by promoting the
accumulation of glycogen (glucose) in the liver. The
deficiency of insulin is known as diabetes mellitus.
Glucagon, produced by α cells, has the
opposite effect of insulin—it raises blood glucose levels.

31. DIABETES MELLITUS
Diabetes mellitus (2 TYPES) is a serious disorder in
which cells are unable to obtain glucose from the
blood, resulting in high blood glucose levels.
The kidneys excrete the excess glucose, and water
follows, resulting in excessive volumes of urine
and persistent thirst.
Because cells cannot take up glucose, they use the
body’s supply of fats and proteins for energy.

32. Adrenal glands
The human body has two adrenal glands on top of
the kidneys.
Each almond-size adrenal gland is actually two
glands in one: an inner core, called the adrenal
medulla, and an outer shell, called the adrenal
cortex.

33. Adrenal gland hormones
ADRENAL MEDULLA:
It produces epinephrine (adrenalin) and
norepinephrine (noradrenalin) as a response to stress
situations (fear, danger, cold…)
They increase heart rate, blood pressure, blood glucose
level, blood flow into heart and lungs (Fight or Flight
response)
ADRENAL CORTEX:
Produces cortisol, aldosterone, small amounts of
testosterone
Cortisol makes more energy available to the body.
Aldosterone helps reabsorb sodium (Na+) ions from the
fluids removed by the kidneys so that these ions are not
lost in the urine.

34. Pineal gland
The pineal gland is a
pea-sized gland located
in the brain, which
secretes the hormone
melatonin.
Melatonin seems to be
released by the human
pineal gland as a
response to darkness.
Therefore, the pineal
gland is involved in
establishing daily
biorhythms.

36. Thymus
The thymus is a
lymphoid organ.
It is involved in the
immune system during
prenatal and postnatal
periods by stimulating
lymphocyte
production by its
hormones.

38. Gonads
The main function of the male and female
gonads is in the development of the
reproductive system and secondary sexual
characteristics (even behavior).
They are both endocrine and exocrine glands
Male gonads TESTES, female gonads OVARIES
The ovaries secrete estrogens and
progesterone, and the testes produce
testosterone.
Exocrine function is in the production of
gametes (sperm and egg)