3. Hormones
• Chemical messengers
• Enter directly into the bloodstream
• Regulate and integrate body functions
• Play role in body’s metabolism and
growth
4. Endocrine Glands
• Are ductless glands
• Consists of cells that produce internal
secretions called hormones
5. How The Endocrine System
Works
• Cells of endocrine glands secrete hormones
into the extracellular fluid
• Hormones enter the capillaries through
diffusion and secrete directly into the
bloodstream (plasma part of the blood)
• Through blood circulation, these hormones
can be distributed all over our body
7. Pituitary Gland
• Small gland about the size of a corn at the
base of the brain
• Connected to the hypothalamus by a stalk
• Master gland
• Secretes hormones like Growth Hormone
(GH) & Thyroid Stimulating Hormone (TSH)
- GH Influences body size and growth
- TSH influences the thyroid gland to release
its thyroxine.
8.
9. Pineal Gland
• Pear-shaped structure at the back of
the base of the brain
• Behind the junction of the spinal cord
and brain tissue
• Smaller than a pea
• SECRETES: MELATONIN
- influences the biological rhythm of an
organism.
10.
11. Thyroid Gland
• Large gland below the larynx at the
base of the neck
• Regulation of metabolism related to
growth
• Secretes: Thyroxine
- It influences the rate of metabolism
and physical development.
12. Parathyroid Glands
• Four small glands at the back of the
thyroid gland
• Secretes: Parathyroid Hormone (PTH)
• Control and maintain plasma
concentration of calcium and
phosphorus
13.
14. Thymus
• Located above the heart and under the
breast bone
• SECRETES: Thymosin that promotes
maturation of the immune system
• Lymphocytes are also produced by this
gland
• Vital in the defense against body
diseases
15. Adrenal Glands
• Two glands located on top of each kidney
• Two parts: adrenal cortex and medulla
– Adrenal cortex SECRETES cortin, responsible for
the control of fat, carbohydrates, protein
metabolism
– Medulla SECRETES epinephrine/adrenalin which
are the glands of emergency. The adrenaline is
released during emergency situations or when the
body is stressed.
16.
17. Pancreas
• Large gland located below and behind
the stomach
• Consists of cells called ISLETS OF
LANGERHANS that SECRETE Insulin and
Glucagon
– Insulin decreases blood sugar level
– Glucagon increases blood sugar level
18.
19. Gonads
• Sex glands (Ovaries and Testes)
• Control development of secondary sex
characteristics that change from
childhood to adulthood
• Ovaries (located at the pelvis)
– Secrete Estrogen and Progesterone
• Testes (below the pelvis)
– Secrete Testosterone
