The endocrine system is comprised of glands that secrete hormones directly into the bloodstream to regulate distant organs and systems. The major endocrine glands include the pituitary, thyroid, parathyroid, adrenal, pancreas, ovaries, testes, and pineal glands. These glands secrete hormones that govern critical body functions like reproduction, stress response, growth, energy levels, and homeostasis. The hormones travel through the circulatory system to target organs and allow for integration of body systems and physiological equilibrium.

1. ENDOCRINE SYSTEM

3. Definition
Endocrine System refers to the collection of glands of an organism that
secrete hormones directly into the circulatory system to be carried toward a distant
target organ.
includes all of the glands of the body and the hormones produced by those glands.
Major endocrine glands
 pineal gland
 pituitary gland
 pancreas
 ovaries
 testes
 thyroid gland
 parathyroid gland
 hypothalamus
 gastrointestinal tract
 adrenal glands
There are up to 20 major
hormones secreted by the
gland in the endocrine system
which are essential to different
tasks throughout the body.

4. Here are a few of the areas governed
by the endocrine system
 Reproduction
 Responses to stress and injuries
 Growth and sexual development
 Body energy levels
 Internal balance of body systems
 Bone and muscle strength

5. Functions of the Endocrine System
 Controls the processes involved in movement and
physiological equilibrium
 Includes all tissues or glands that secrete hormones into the
blood
 Secrete hormones directly into the bloodstream.
 Integrate body systems

6. TERMS
 ENDOCRINE GLAND a gland that secretes hormones
directly into the bloodstream; a ductless gland.
 HORMONES is a very powerful substance secreted by an
endocrine gland into the bloodstream, that affects the
function of another cell or "target cell".
 HOMEOSTASIS is the maintenance of the constant
internal environment which include the function of
kidney, liver, skin, etc.

7. Major Endocrine Glands

8. Pituitary Gland
(Hypophysis)

 It is also known as the “master gland”
 It is a master in controlling other glands of the
body ( thyroid, adrenal glands, and gonads
 It is consists of anterior pituitary and posterior
pituitary glands.

9. Anterior Pituitary Glands
( Adenohypophysis)
 Hormone stimulates the thyroid gland,
adrenal glands and gonads
 It secretes other hormones like
melanocyte stimulating hormone
responsible for skin color
 Prolactin stimulating milk production
for lactating mothers
 Somatotropin (growth hormone)
 Giantism and dwarfism
 LH,MSH, FLH

10. Anterior Pituitary Glands
 It has three region :
1. Pars distalis – It is the largest and
vascular lobe, it is the major secretory
of the gland
2. Pars tuberalis – it joins the pituitary
stalk arising from the posterior gland
3. Pars intermedia – it is located
between the pars distalis and posterior
gland, it serves as the boundary
between anterior and posterior gland (
it is very small and indistinct to
humans)

11. Posterior Pituitary Glands
(Neurohypophysis)
 It releases vasopressin
hormones to control the amount
of water
 Oxytocin secreted during
childbirth in stimulating
muscular contraction of the
uterus and ejection of milk from
lactating mammary gland

12. 2 Regions of the Posterior Pituitary
Gland
 Pars Nervosa
- It is also called as “posterior lobe”
- Is the storage site of Oxytocin and Vasopressin
 Infundibular stalk
- the connection between the hypothalamus and the posterior
pituitary.

13. Thyroid Glands
 It is located in the neck at the back of the
Adam’s apple
 It secretes three hormones :
- T3 (triiodothyronine)
- T4 (thyroxin)
- Calcitonin – lowers down the blood
calcium level of the body
 Both T3 and T4 contain the iodine element
which regulate the metabolism and play a
crucial role in development ad maturation.
 Hyperthyroidism- excess of T3 and T4
 Hypothyroidism- insufficient of T3 and
T4

14.  HYPOTHYROIDISM
-is an underactivity of the
thyroid gland causing laziness,
dullness, and goiter.
 HYPERTHYROIDISM
- having an active behavior
resulting to loss of weight and
insomnia.

15. Parathyroid Gland
 It is located at the back of the thyroid
gland
 The parathormone regulates the
utilization of calcium and phosphorus in
the blood level of the body
 Too much secretion of the parathormone
presents poor physical coordination
 Less secretion can lead to “tetany” is
the intermittent, involuntary twitching and
spasms of the muscle

16. Adrenal Glands
 It is located at the top or above the kidney
 Adrenalin, the hormone it produces
 It has two parts the inner part which is the
“medulla” and the outer part which is the
“cortex”
 Medulla is the source of epinephrine(adrenalin)
and Non-epinephrine. Epinephrine raises blood
sugar levels, cause nervousness and perspirations
on acute emergencies.
 Cortex releases cortisone which is essential
for adapting to stress and maintaining blood sugar
level and aldosterone that regulates the salt
and water balance of the body.

17. Gonads
 It stimulates the secondary sex
characteristics for boys and girls during
puberty stage
 The appearance of pubic hair, hair at the
armpit etc.
 The male gonads secrete the hormone
“androgen” that contain testosterone which
influences the growth of prostate, seminal
vesicles, the production of sperm
 The female gonads secrete the hormones
“estrogen” which is necessary for the
development of the reproductive organ and “
progesterone” which is essential for
maintaining pregnancy located at the paired
ovaries

18. Pancreas
 It is located near the stomach at the
right side of the abdomen at the level
of the umbilicus
 The hormones and insulin are found at
the “Islets of Langerhans” of the
pancreas.
 Insulin plays an important role in
keeping the levels of sugar(glucose) in
the bloodstream under control.
 Glucagon increases the level of sugar
in the body if the insulin is absent or
lacking.

19. Pineal Gland
 It is situated at the mid-cerebrum
 It releases melatonin that
regulates body rhythms and
sleeping patterns.

20. THE
END!!! 
Prepared By:
Prepared by:
Patricia Francisco
Monique Burgos