1. Endocrine System A chemical communication system of the body tissue
Types of communication
Gap Junctions: similar to pores that are connected, allow signal molecules to pass from cell to cell
Neurotransmitters
Paracrines (Local hormones): a cell of tissue that stimulates other cells around them with secretion
Hormones: chemical messenger that travels through blood and stimulates target cells

2. Hypothalamus & Pituitary Gland
Most important glands in system they have the largest effect on bodily functions
They are closely related the pituitary sits on a structure of the hypothalamus. The hypothalamus often acts through the neurohypophysis(posterior pituitary)

3. Hypothalamus Is connected to the third ventricle of the brain
It regulates primitive body functions from hydration to sex drive
It produces 9 hormones five that stimulate the pituitary, two that inhibits and two that are secreted through the posterior pituitary(oxytocin (OT), antidiuretic hormone (ADH))

4. Pituitary Gland
Made of two parts the adenohypophysis and neurohypophysis
Adenohypophysis: also known as the anterior lobe. It has no nervous connection it only responds to hormone interaction
Neurohypophysis: posterior lobe. It is only ¼ the size of the anterior lobe. It has nervous connection and is not a true gland it is a collection of different tissue. Contains the hypothalamic stalk.

5. Pituitary Hormones Most of the pituitary hormones are trophic hormones
Trophic hormones: stimulates other endocrine organs to secrete their own hormones
Axis: the interaction between the hypothalamus, pituitary and a remote endocrine gland. (There are 3 different axis)

6. Posterior Pituitary Lobe
It doesn’t produce any hormones it just stores two OT and ADH
OT: causes contraction of the uterus darning Birth, contraction of lactation, contraction during sexual response
ADH: Controls hydration and vasoconstriction

7. Anterior Lobe
Follicle Stimulating Hormone(FSH): targets gonads causes the development of eggs and sperm
Luteinizing Hormone(LH): targets gonads in females causes ovulation, in males cause production of testosterone
Thyrotropin(TSH): targets thyroid effects metabolism

8. Anterior Lobe
Corticotropin(ACTH): targets adrenal cortex effects sugar, fat and protein metabolism (“cortisol”)
Prolactin(PRL): targets mammary glands increase in number and production
Growth Hormone(GH): targets all tissue is produced 1000 times more than any other hormone promotes mitosis thus tissue growth