Endocrine System

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 doesnt 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