Human endocrine system

ENDOCRINE SYSTEM
JAI NARAIN VYAS UNIVERSITY, JODHPUR
ASSISTANT PROFESSOR:- ASHWIN SINGH
CHOUHAN
DEPARTMENT:- PHARMACOLOGY
E-mail:- anshukavya1993@gmail.com

JNVU PHARMACY, JODHPUR
The endocrine system is the collection of glands that
produce hormones that regulate metabolism, growth and
development, tissue function, sexual function,
reproduction, sleep, and mood, among other things.
THE ENDOCRINE SYSTEM

ENDOCRINE SYSTEM FUNCTIONS
Your endocrine system
Makes hormones that control your moods, growth and
development, metabolism, organs, and reproduction.
Controls how your hormones are released.
Sends those hormones into your bloodstream so they
can travel to other body parts.

ENDOCRINE SYSTEM

PARTS OF THE ENDOCRINE
SYSTEM

HYPOTHALAMUS
The hypothalamus is a
small but important area
in the center of the
brain. It plays an
important role in
hormone production and
helps to stimulate many
important processes in
the body and is located
in the brain, between the
pituitary gland and
thalamus.

The hypothalamus’ main role is to keep the body in
homeostasis as much as possible. Homeostasis means a
healthful, balanced bodily state. The body is always trying
to achieve this balance. Feelings of hunger, for example,
are the brain’s way of letting its owner know that they
need more nutrients to achieve homeostasis. The
hypothalamus acts as the connector between the
endocrine and nervous systems to achieve this. It plays a
part in many essential functions of the body such as:
body temperature
thirst
appetite and weight control
emotions
sleep cycles
sex drive
childbirth
blood pressure and heart rate
production of digestive juices
balancing bodily fluids

HORMONES OF THE HYPOTHALAMUS
Hormones secreted by the hypothalamus include:
ANTIDIURETIC HORMONE, which increases how much
water is absorbed into the blood by the kidneys
CORTICOTROPIN-releasing hormone, which helps
regulate metabolism and immune response by working
with the pituitary gland and adrenal gland to release
certain steroids
GONADOTROPIN-releasing hormone, which instructs
the pituitary gland to release more hormones that keep
the sexual organs working

OXYTOCIN- A hormone involved in several processes,
including the release of a mother’s breast milk,
moderating body temperature, and regulating sleep
cycles
PROLACTIN-Controlling hormones, which tell the
pituitary gland to either start or stop breast milk
production in lactating mothers
THYROTROPIN-Releasing hormone activates the
thyroid, which releases the hormones that regulate
metabolism, energy levels, and developmental growth

PITUITARY GLAND
The pituitary gland is small
and oval-shaped. It’s
located behind your nose,
near the underside of your
brain. It’s attached to
the hypothalamus by a stalk
like structure.
The hypothalamus is a small
area of your brain. It’s very
important in controlling the
balance of your bodily
functions. It controls the
release of hormones from
the pituitary gland.

The pituitary gland can be divided into two different
parts: the anterior and posterior lobe
ANTERIOR LOBE
The anterior lobe of your pituitary gland is made up of
several different types of cells that produce and release
different types of hormones, including:
Growth hormone - Growth hormone regulates growth
and physical development. It can stimulate growth in
almost all of your tissues. Its primary targets are bones
and muscles.
Thyroid-stimulating hormon- This hormone activates
your thyroid to release thyroid hormones. Your thyroid
gland and the hormones it produces are crucial for
metabolism.
Adreno-corticotropic hormone-
This hormone stimulates your adrenal glands to produce
cortisol and other hormones.

Follicle-stimulating hormone- Follicle-stimulating
hormone is involved with estrogen secretion and the
growth of egg cells in women. It’s also important for
sperm cell production in men.
Luteinizing hormone- Luteinizing hormone is involved
in the production of estrogen in women and testosterone
in men.
Prolactin- Prolactin helps women who are breastfeeding
produce milk.
Endorphins- Endorphins have pain-relieving properties
and are thought to be connected to the “pleasure
centers” of the brain.
Enkephalins- Enkephalins are closely related to
endorphins and have similar pain-relieving effects.
Beta-melanocyte-stimulating hormone-This hormone
helps to stimulate increased pigmentation of your skin in
response to exposure to ultraviolet radiation.

POSTERIOR LOBE
The posterior lobe of the pituitary gland also secretes
hormones. These hormones are usually produced in your
hypothalamus and stored in the posterior lobe until
they’re released.
Hormones stored in the posterior lobe include:
Vasopressin- This is also called antidiuretic hormone. It
helps your body conserve water and prevent dehydration.
Oxytocin- This hormone stimulates the release of breast
milk. It also stimulates contractions of the uterus during
labor.

PINEAL GLAND
The pineal gland (also
called the pineal body or
epiphysis) is a small
endocrine gland in the
brain. It is located near
the center of the brain,
between the two
hemispheres, tucked in
a groove where the two
rounded thalamic bodies
join.

The pineal gland is a reddish-gray body about the size of
a pea (8 mm in humans) located just rostro-dorsal to the
superior colliculus and behind and beneath the stria
medullaris, between the laterally positioned thalamic
bodies.
It is part of the epithalamus.The pineal gland is a midline
structure, and is often seen in plain skull X-rays, as it is
often calcified. The main hormone produced and secreted
by the pineal gland is melatonin. Secretion is highest at
night and between the ages of 0-5.
PINEAL GLAND HORMONES
Melatonin
While the full function of the pineal gland is still
somewhat mysterious, we do know that it secretes the
hormone melatonin. Melatonin is a hormone from the
pineal gland that helps regulate biological rhythms such
as sleep and wake cycles.

In other words, it's melatonin that directs your internal
clock - the one that allows you to wake up about the
same time every morning without an alarm clock.
Melatonin is secreted in different amounts during the
night and day. Melatonin secretions peak during the
nighttime, and this makes you feel drowsy. While it does
not necessarily induce sleep, it can promote sleep and
allow a good night's rest. In fact, we see melatonin
marked as a supplement to help people who deal with
insomnia. Because melatonin secretions peak during
puberty and then continue to drop through out life, it is
thought that a lack of melatonin production is why so
many elderly people report trouble sleeping.

THYROID GLAND
The thyroid is a butterfly-
shaped gland that sits low on
the front of the neck. Your
thyroid lies below your
Adam’s apple, along the
front of the windpipe. The
thyroid has two side lobes,
connected by a bridge
(isthmus) in the middle.
When the thyroid is its
normal size, you can’t feel it.
Brownish-red in color, the
thyroid is rich with blood
vessels. Nerves important for
voice quality also pass
through the thyroid

THYROID HORMONES
Your thyroid makes 2 main hormones –triiodothyronine
(T3) and thyroxine (T4). Adequate amounts
of iodine (a chemical element that’s an essential part of
our diet) are needed for the thyroid to be able to make
these hormones.
Another hormone that’s produced in your thyroid gland is
called calcitonin. This hormone, secreted by a small
population of cells known as C cells, is involved in
regulating the level of calcium and phosphate in your
blood.

The main thyroid hormones are secreted directly into the
bloodstream and go to all parts of your body. Most T4 is
converted to T3 (the active form of the hormone) in your
organs and tissues. Thyroid hormones affect your body’s
metabolic rate and regulate many of your bodily functions
such as breathing, heart rate, body temperature,
digestion and how quickly you burn calories.
The amount of hormones your thyroid makes is usually
tightly regulated. A part of your brain called
the hypothalamus signals your pituitary gland (an
important gland in your brain) to produce a hormone
called thyroid stimulating hormone (TSH). TSH then
signals your thyroid to make T3 and T4. The level of
thyroid hormones in your body then feeds back to the
hypothalamus and the pituitary, which in turn adjust the
release of TSH

PARATHYROID
The parathyroid glands are
tiny, round structures usually
found embedded in the posterior
surface of the thyroid gland A
thick connective tissue capsule
separates the glands from the
thyroid tissue. Most people have
four parathyroid glands, but
occasionally there are more in
tissues of the neck or chest. The
function of one type of
parathyroid cells, the oxyphil
cells, is not clear. The primary
functional cells of the parathyroid
glands are the chief cells. These
epithelial cells produce and
secrete the parathyroid
hormone (PTH), the major
hormone involved in the
regulation of blood calcium levels.

The parathyroid glands produce and secrete PTH, a
peptide hormone, in response to low blood calcium levels
PTH secretion causes the release of calcium from the
bones by stimulating osteoclasts, which secrete enzymes
that degrade bone and release calcium into the interstitial
fluid. PTH also inhibits osteoblasts, the cells involved in
bone deposition, thereby sparing blood calcium. PTH
causes increased reabsorption of calcium (and
magnesium) in the kidney tubules from the urine filtrate.
In addition, PTH initiates the production of the steroid
hormone calcitriol (also known as 1,25-dihydroxyvitamin
D), which is the active form of vitamin D3, in the kidneys.
Calcitriol then stimulates increased absorption of dietary
calcium by the intestines. A negative feedback loop
regulates the levels of PTH, with rising blood calcium
levels inhibiting further release of PTH.

THYMUS
The thymus gland is a
small organ behind the
breastbone that plays an
important function both in
the immune system and
endocrine system. Though
the thymus begins to
atrophy (decay) during
puberty, its effect in
"training“T lymphocytes to
fight infections and even
cancer lasts for a lifetime.

CELLS OF THE THYMUS
A number of different cell types are present within the
thymus gland.
Epithelial cells: cells that line body surfaces and cavities
Kulchitsky cells: cells that are the hormone-producing
cells of the thymus or neuroendocrine cells
Thymocytes: cells that become mature T lymphocytes
HORMONE PRODUCTION
The thymus gland produces several hormones including:
thymopoietin and thymulin, which are hormones that
assist in the process where T cells differentiate into
different types thymosin, which accentuates the immune
response as well as stimulating pituitary hormones such
as growth hormone thymic humoral factor, which acts
similarly to thymosin, but increases the immune response
to viruses in particular.

The thymus gland may produce small amounts of some
hormones produced in other areas of the body, such as
melatonin and insulin. Cells in the thymus gland (such as
epithelial cells) also have receptors through which other
hormones can regulate its function.

ADRENALS
Adrenal glands, also known as
suprarenal glands, are small,
triangular-shaped glands located
on top of both kidneys. Adrenal
glands produce hormones that help
regulate your metabolism, immune
system, blood pressure, response
to stress and other essential
functions. Adrenal glands are
composed of two parts the cortex
and the medulla which are each
responsible for producing different
hormones.

When adrenal glands don’t produce enough hormones,
this can lead to adrenal insufficiency (Addison’s disease).
Adrenal glands may develop nodules that can be benign
or malignant, which can potentially produce excessive
amounts of certain hormones leading to various health
issues
AADRENAL GLAND IS MADE OF TWO MAIN PARTS
The adrenal cortex is the outer region and also the
largest part of an adrenal gland. It is divided into three
separate zones: zona glomerulosa, zona fasciculata and
zona reticularis. Each zone is responsible for producing
specific hormones.
The adrenal medulla is located inside the adrenal cortex
in the center of an adrenal gland. It produces “stress
hormones,” including adrenaline.
The adrenal cortex and adrenal medulla are enveloped in
an adipose capsule that forms a protective layer around
an adrenal gland

HORMONES OF THE ADRENAL GLANDS
Adrenal Cortex Hormones
The adrenal cortex produces two main groups of
corticosteroid hormones— glucocorticoids and
mineralcorticoids. The release of glucocorticoids is
triggered by the hypothalamus and pituitary gland.
Mineralcorticoids are mediated by signals triggered by the
kidney.
When the hypothalamus produces corticotrophin-
releasing hormone (CRH), it stimulates the pituitary gland
to release adrenal corticotrophic hormone (ACTH). These
hormones, in turn, alert the adrenal glands to produce
corticosteroid hormones.

Glucocorticoids released by the adrenal cortex include:
Hydrocortisone: Commonly known as cortisol, it
regulates how the body converts fats, proteins, and
carbohydrates to energy. It also helps regulate blood
pressure and cardiovascular function.
Corticosterone: This hormone works with
hydrocortisone to regulate immune response and
suppress inflammatory reactions.
The principle mineralcorticoid is aldosterone, which
maintains the right balance of salt and water while
helping control blood pressure.
There is a third class of hormone released by the adrenal
cortex, known as sex steroids or sex hormones. The
adrenal cortex releases small amounts of male and
female sex hormones. However, their impact is usually
overshadowed by the greater amounts of hormones (such
as estrogen and testosterone) released by
the ovaries or testes. JNVU PHARMACY, JODHPUR

ADRENAL MEDULLA HORMONES
Hormones secreted by the adrenal medulla are
Epinephrine: Most people know epinephrine by its other
name—adrenaline. This hormone rapidly responds to
stress by increasing your heart rate and rushing blood to
the muscles and brain. It also spikes your blood sugar
level by helping convert glycogen to glucose in the liver.
(Glycogen is the liver’s storage form of glucose.)
Norepinephrine: Also known as noradrenaline, this
hormone works with epinephrine in responding to stress.
However, it can cause vasoconstriction (the narrowing of
blood vessels). This results in high blood pressure.

PANCREAS
The pancreas is an abdominal
organ that is located behind
the stomach and is surrounded
by other organs, including the
spleen, liver and small
intestine. The pancreas is
about 6 inches (15.24
centimeters) long, oblong and
flat.
The pancreas plays an
important role in digestion and
in regulating blood sugar.
Three diseases associated with
the pancreas are pancreatitis,
pancreatic cancer and
diabetes.

The pancreas maintains the body’s blood glucose
(sugar) balance.
Primary hormones of the pancreas include insulin and
glucagon, and both regulate blood glucose.
Diabetes is the most common disorder associated with
the pancreas.
The pancreas is unique in that it’s both an endocrine and
exocrine gland. In other words, the pancreas has the dual
function of secreting hormones into blood (endocrine)
and secreting enzymes through ducts (exocrine).

HORMONES OF THE PANCREAS
The production of pancreatic hormones, including insulin,
somatostatin, gastrin, and glucagon, play an important
role in maintaining sugar and salt balance in our bodies.
Primary hormones secreted by the pancreas include:
Gastrin: This hormone aids digestion by stimulating
certain cells in the stomach to produce acid.
Glucagon: Glucagon helps insulin maintain normal blood
glucose by working in the opposite way of insulin. It
stimulates your cells to release glucose, and this raises
your blood glucose levels.

Insulin: This hormone regulates blood glucose by
allowing many of your body’s cells to absorb and use
glucose. In turn, this drops blood glucose levels.
Somatostatin: When levels of other pancreatic
hormones, such as insulin and glucagon, get too high,
somatostatin is secreted to maintain a balance of glucose
and/or salt in the blood.
Vasoactive intestinal peptide (VIP): This hormone
helps control water secretion and absorption from the
intestines by stimulating the intestinal cells to release
water and salts into the intestines.

OVARIES
The ovaries are oval shaped
and about the size of a
large grape. They are
located on opposite ends of
the pelvic wall, on either
side of the uterus. The
ovaries are each attached to
the fimbria (tissue that
connects the ovaries to the
fallopian tube). The ovaries
are a pair of ova-producing
organs (that is, they
produce egg cells) that
maintain the health of the
female reproductive system

The major hormones secreted by the ovaries are
oestrogen and progesterone, both important hormones in
the menstrual cycle. Oestrogen production dominates in
the first half of the menstrual cycle before ovulation, and
progesterone production dominates during the second
half of the menstrual cycle when the corpus luteum has
formed. Both hormones are important in preparing the
lining of the womb for pregnancy and the implantation of
a fertilised egg, or embryo.
If conception occurs during any one menstrual cycle, the
corpus luteum does not lose its ability to function and
continues to secrete oestrogen and progesterone,
allowing the embryo to implant in the lining of the womb
and form a placenta. At this point, development of the
foetus begins.

TESTES
The testes are twin oval-
shaped organs about the
size of a large grape. They
are located within the
scrotum, which is the loose
pouch of skin that hangs
outside the body behind the
penis. While this location
makes the testes vulnerable
to injury (they have no
muscles or bones to shield
them), it provides a cooler
temperature for the organs.
A cooler environment is
necessary for healthy sperm
production.

The main hormone secreted by the testes is testosterone,
an androgenic hormone. Testosterone is secreted by cells
that lie between the seminiferous tubules, known as the
Leydig cells. The testes also produce inhibin B and anti-
Müllerian hormone from Sertoli cells, and insulin-like
factor 3 and oestradiol from the Leydig cells.
Testosterone is important in the first stages of developing
the male reproductive organs in a foetus. It also causes
the development of male characteristics such as growth
of facial hair, deepening of the voice and the growth spurt
that takes place during puberty. Testosterone is important
in maintaining these secondary male characteristics
throughout a man’s life. From puberty onwards,
testosterone provides the main stimulus for sperm
production.

ENDOCRINE SYSTEM
DISORDERS
Acromegaly. Sometimes the pituitary gland makes too
much growth hormone and your bones get bigger. It
usually affects your hands, feet, and face. It usually
starts in middle age.
Adrenal insufficiency. When you have this, your
adrenal glands don’t make enough of certain hormones,
like cortisol, which controls stress.
Cushing's disease. In this, your body makes too much
cortisol. You could gain weight, get stretch
marks, bruise easily at first, then get weakened muscles
and bones and possibly develop a hump on your upper
back.

Hyperthyroidism. This is when your thyroid gland
makes more hormones than your body needs. You might
hear it called overactive thyroid. It makes your system
run fast and you might feel nervous, lose weight, and
have a rapid heartbeat or trouble sleeping.
Hypothyroidism. When your body doesn’t make enough
thyroid hormone, your system slows down. You might
feel tired, gain weight, have a slow heartbeat, and
get joint and muscle pains.
Hypopituitarism. Sometimes your pituitary gland
doesn’t make enough of certain hormones and your
adrenal and thyroid glands can’t work right.

Multiple endocrine neoplasia. This is a group of
disorders that affect your endocrine system. It causes
tumors on at least two endocrine glands or in other
organs and tissues.
Polycystic ovary syndrome. An imbalance of
reproductive hormones can cause your ovaries to either
not make an egg or not release it during ovulation. This
can throw off your periods, cause acne, and make hair to
grow on your face or chin.
Precocious puberty . When glands that control
reproduction don’t work properly, some kids start puberty
abnormally early -- around 8 in girls and 9 in boys

Endocrine
Gland
Hormone Released Chemical Class Target
Tissue/Organ
Major Function of
Hormone
(1) Hypothalamus Hypothalamic
releasing and
inhibiting
hormones
Peptide Anterior pituitary Regulate anterior
pituitary hormone
(2) a. Posterior
Pituitary
Antidiuretic (ADH) Peptide Kidneys Stimulates water
reabsorption by
kidneys
Oxytocin Peptide Uterus, mammary
glands
Stimulates uterine
muscle
contractions and
release of milk by
mammary glands
b. Anterior
Pituitary
Thyroid stimulating
(TSH)
Glycoprotein Thyroid Stimulates thyroid
Adrenocorticotropi
c (ACTH)
Peptide Adrenal cortex Stimulates adrenal
cortex
SUMMARY

Gonadotropic (FSH,
LH)
Glycoprotein Gonads Egg and
sperm
production, sex
hormone
production
Prolactin (PRL) Protein Mammary glands Milk production
Growth (GH) Protein Soft tissue, bones Cell division,
protein synthesis
and bone growth
(3) Thyroid Thyroxine (T4) and
Triiodothyronie
(T3)
Iodinated amino
acid
All tissue Increase metabolic
rate, regulates
growth and
development
Calcitonin Peptide Bones, kidneys and
intestine
Lowers blood
calcium level

(4) Parathyroids Parathyroid (PTH) Peptide Bones, kidneys
and
intestine
Raises blood calcium
level
(5) a. Adrenal
Cortex
Glucocorticoids
(cortisol)
Steroid All tissue Raise blood glucose
level, stimulates
breakdown
of protein
Mineralocorticoids
(aldosterone)
Steroid Kidneys Reabsorb sodium and
excrete potassium
Sex Hormones Steroid Gonads, skin,
muscles
and bones
Stimulates
reproductive organs
and brings on sex
characteristics
b. Adrenal
Medulla
Epinephrine and
norepinephrine
Modified amino
acid
Cardiac and
other
muscles
Released in emergency
situations, raises blood
glucose level, “fight or
flight” response

(6) Pancreas Insulin Protein Liver, muscles,
adipose tissue
Lowers blood glucose
levels, promotes
formation
of glycogen
Glucagon Protein Liver, muscles,
adipose tissue
Raises blood glucose
levels
(7) Testes Androgens
(testosterone)
Steroid Gonads, skin,
muscles
and bone
Stimulates male sex
characteristics
(8) Ovaries Estrogen and
progesterone
Steroid Gonads, skin,
muscles
and bones
Stimulates female sex
characteristics
(9) Thymus Thymosins Peptide T lymphocytes Stimulates production
and maturation of T
lymphocytes
(10) Pineal Gland Melatonin Modified amino
acid
Brain Controls circadian and
circannual rhythms,
possibly involved in
maturation of sexual
organs

THANK YOU

Human endocrine system

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Human endocrine system

Similar to Human endocrine system (20)

More from Jai Narain Vyas University Jodhpur Rajasthan India 342003

More from Jai Narain Vyas University Jodhpur Rajasthan India 342003 (20)

Recently uploaded

Recently uploaded (20)

Human endocrine system