2. ENDOCRINE SYSTEM
The endocrine system includes all of the glands of the body and the hormones produced by those glands.
The glands are controlled directly by stimulation from the nervous system as well as by chemical receptors in the blood and hormones produced by other glands.
By regulating the functions of organs in the body, these glands help to maintain the body’s homeostasis.
Cellular metabolism, reproduction, sexual development, sugar and mineral homeostasis, heart rate, and digestion are among the many processes regulated by the actions of hormones.

4. GLANDULAR TISSUE

5. WHAT IS A HORMONE?

6. ENDOCRINE GLANDS

7. THYROIDS
Thyroids is a butterfly-shaped gland located at the base of the neck and wrapped around the lateral sides of the trachea. The thyroid gland produces 3 major hormones:
Calcitonin
Triiodothyronine (T3)
Thyroxine (T4)
Calcitonin functions to reduce the concentration of calcium ions in the blood by aiding the absorption of calcium into the matrix of bones.
The hormones T3 and T4 work together to regulate the body’s metabolic rate. Increased levels of T3 and T4 lead to increased cellular activity and energy usage in the body.

8. PARATHYROIDS
Prathyroids are 4 small masses of glandular tissue found on the posterior side of the thyroid gland.
The parathyroid glands produce the hormone parathyroid hormone (PTH), which is involved in calcium ion homeostasis.

9. ADRENALS
The adrenal glands are a pair of roughly triangular glands found immediately superior to the kidneys.

10. PANCREAS
The pancreas is a large gland located in the abdominal cavity just inferior and posterior to the stomach.
The pancreas is considered to be a heterocrine gland as it contains both endocrine and exocrine tissue.
Endocrine glands produce two hormones:
Glucagon, which is responsible for raising blood glucose levels.
Insulin, which is responsible for lowering blood glucose levels after a meal. Insulin triggers the absorption of glucose from the blood into cells, where it is added to glycogen molecules for storage.

11. PANCREAS

13. Progesterone: prepares the wall of the uterus so that the lining is able to accept a fertilized egg, implanted and develop.
Estrogens: It is responsible for the development and regulation of the female reproductive system and secondary sex characteristics.
Testosterone (androgens): plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics

14. HYPOTHALAMUS
One of the most important functions of the hypothalamus is to link the nervous system to the endocrine system via the pituitary gland (hypophysis).
It synthesizes and secretes certain neurohormones, and these in turn stimulate or inhibit the secretion of pituitary hormones.
The hypothalamus controls body temperature, hunger, important aspects of parenting and attachment behaviours, thirst, fatigue, sleep, and circadian rhythms.

16. NEUROSECRETORY CELLS

17. HYPOPHYSIS

19. PINEAL GLAND
The pineal gland produces melatonin, a serotonin-derived hormone which modulates sleep patterns in both circadian and seasonal cycles
Pineal Gland

20. COMPARISION BETWEEN NERVOUS AND ENDOCRINE SYSTEMS
NERVOUS SYSTEM
Movement of messages
By chemical messengers through the bloodstreem
By electrical impulse within the neuron and by chemical Messenger between neurons
Chemical messenger
Hormones
Neurotransmitters
Speed of transmission
Slow
Fast
Distance covered by chemical messenger
Very large
Very small
Effect (speed and duration)
Slow and long-lasting
Immediate, short-lived
Effector
Target cells (into the organs and glands)
Muscle cells or glands