Introduction about endocrine hormones

1. ENDOCRINE GLANDS
BY
K. RAVICHANDRAN

2. INTRODUCTION
 The endocrine system is a network of glands and organs located
the body. It’s similar to the nervous system in that it plays a vital
controlling and regulating many of the body’s functions.
 However, while the nervous system uses nerve impulses and
for communication, the endocrine system uses chemical
hormones.
 The endocrine system is responsible for regulating a range of
through the release of hormones.
 Hormones are secreted by the glands of the endocrine system,
through the bloodstream to various organs and tissues in the

3. Endocrine Glands & TheirHormones
 The endocrine system is made up of a complex
network of glands, which are organs that
secrete substances.
 The glands of the endocrine system are where
hormones are produced, stored, and released.
Each gland produces one or more hormones,
which go on to target specific organs and
tissues in the body.
 Although there are eight major endocrine
glands scattered throughout the body, they are
still considered to be one system because they
have similar functions, similar mechanisms of
influence, and many important
interrelationships.

4. 1. Hypothalamus. While some people don’t consider it a gland,
the hypothalamus produces multiple hormones that control the pituitary gland. It’s
also involved in regulating many functions, including sleep-wake cycles, body
temperature, and appetite. It can also regulate the function of other endocrine
glands.
2. Pituitary. The pituitary gland is located below the hypothalamus. The hormones it
produces affect growth and reproduction. They can also control the function of other
endocrine glands.
3. Pineal. This gland is found in the middle of your brain. It’s important for your sleep-
wake cycles.
4. Thyroid. The thyroid gland is located in the front part of your neck. It’s very
important for metabolism.

5. 5. Parathyroid. Also located in the front of your neck, the parathyroid gland is
important for maintaining control of calcium levels in your bones and blood.
6. Thymus. Located in the upper torso, the thymus is active until puberty and
produces hormones important for the development of a type of white blood cell
called a T cell.
7. Adrenal. One adrenal gland can be found on top of each kidney. These glands
produce hormones important for regulating functions such as blood pressure, heart
rate, and stress response.
8. Pancreas. The pancreas is located in your abdomen behind your stomach. Its
endocrine function invol

6. Chemical Nature of Hormones
Chemically, hormones may be classified as either proteins or steroids. All of
the hormones in the human body, except the sex hormones and those from
the adrenal cortex, are proteins or protein derivatives.
Mechanism of Hormone
Action Hormones are carried by the blood throughout the entire body, yet they
affect only certain cells. The specific cells that respond to
given hormone have receptor sites for that hormone. This is sort of a lock-and-key
mechanism. If a hormone fits the receptor site, then there will be an effect. If a hormone
and a receptor site do not match, then there is no reaction. All the cells that have
receptor sites for a given hormone make up the target tissue for that hormone. In some
cases, the target tissue is localized in a single gland or organ. In other cases, the target
tissue is diffuse and scattered throughout the body so that many areas are affected.
Protein hormones react with receptors on the surface of the cell. Steroid hormones
typically react with receptor sites inside a cell. Because this method of action actually
involves synthesis of proteins, it is relatively slow.

7. Control of Hormone Action
Hormones are very potent substances, which means that very small
amounts of a hormone may have profound effects on metabolic processes. Because
of their potency, hormone secretion must be regulated within very narrow limits in
order to maintain homeostasis in the body.
Many hormones are controlled by some form of a negative feedback
mechanism. In this type of system, a gland is sensitive to the concentration of a
substance that it regulates. A negative feedback system causes a reversal of
increases and decreases in body conditions in order to maintain a state of stability or
homeostasis. Some endocrine glands secrete hormones in response to other
hormones. The hormones that cause secretion of other hormones are called tropic
hormones. A hormone from gland A causes gland B to secrete its hormone. A third
method of regulating hormone secretion is by direct nervous stimulation.
A nerve stimulus causes gland A to secrete its hormone.

8. Hormone Secreting Gland(s) Function
Adrenaline Adrenal
Increases blood pressure, heart rate, and
metabolism in reaction to stress
Aldosterone Adrenal Controls the body’s salt and water balance
Cortisol Adrenal Plays a role in stress response
Dehydroepiandrosterone
Sulfate (DHEA)
Adrenal
Aids in production of body odor and growth
of body hair during puberty
Estrogen Ovary
Works to regulate menstrual cycle, maintain
pregnancy, and develop female sex
characteristics; aids in sperm production
Follicle stimulating
hormone (FSH)
Pituitary Controls the production of eggs and sperm
Glucagon Pancreas Helps to increase levels of blood glucose
Insulin Pancreas Helps to reduce your blood glucose levels
Below are some examples of hormones that are produced by the endocrine
system.

9. Luteinizing hormone
(LH)
Pituitary
Controls estrogen and testosterone production as
well as ovulation
Melatonin Pituitary Controls sleep and wake cycles
Oxytocin Pituitary
Helps with lactation, childbirth, and mother-child
bonding
Parathyroid hormone Parathyroid Controls calcium levels in bones and blood
Progesterone Ovary
Helps to prepare the body for pregnancy when an
egg is fertilized
Prolactin Pituitary Promotes breast-milk production
Testosterone
Ovary, teste,
adrenal
Contributes to sex drive and body density in males
and females as well as development of male sex
characteristics
Thyroid hormone Thyroid
Help to control several body functions, including
the rate of metabolism and energy levels

10. Conditions that can affect the endocrine system
Sometimes, hormone levels can be too high or too low.
 Hyperthyroidism  It happens when your thyroid gland makes more thyroid
hormone than necessary. This can be caused by a range of things, including
autoimmune conditions.
 Hypothyroidism  It occurs when your thyroid doesn’t produce enough thyroid
hormone.
 Cushing syndrome  It happens due to high levels of the hormone cortisol.
 Addison disease  It happens when your adrenal glands don’t produce enough
cortisol or aldosterone.

11. Signs or symptoms of a hormonal
imbalance Weight gain
 A hump of fat between the shoulders
 Unexplained, and sometimes sudden, weight loss
 Fatigue, Muscle weakness
 Muscle aches, tenderness, and stiffness
 Pain or swelling in your joints
 Increased or decreased heart rate
 Increased sensitivity to cold or heat
 Frequent urination, Increased thirst, Increased hunger
 Depression
 Nervousness, anxiety, or irritability
 Blurred vision
 Infertility, Thinning hair dry skin

12. Causes of a hormonal imbalance
There are many possible causes of a hormonal imbalance. Causes differ
hormones or glands are affected. Common causes of hormonal imbalance
 Hormone therapy
 Medications
 Cancer treatments such as chemotherapy
 Tumors, whether cancerous or benign
 Pituitary tumors
 Eating disorders
 Stress
 Injury or trauma
 Cushing syndrome, or high levels of cortisol
 Congenital adrenal hyperplasia, which causes low levels of cortisol and
 Hypothyroidism, or an underactive thyroid
 Hyperthyroidism, or an overactive thyroid

13. Treatment options for a hormonal imbalance
1. Hormonal birth control  Hormonal birth control can help
regulate your menstrual cycles. Types of hormonal birth control
include the:
•Birth control pill
•Birth control patch
•Birth control shot
•Vaginal ring
•Intrauterine device (IUD)
It may also help improve acne and reduce extra hair on the face
and body.
2. Oestrogen therapy
3. Anti-androgen medications
4. Thyroid hormone therapy