What is the Endocrine System?

• The endocrine system is a system of organs or glands which are able to release hormones directly into the blood stream.
• Endocrine glands are referred to as ductless glands.
• It would be inefficient to hv ducts if hormones have and effect on multiple target organs.
• These Hormones enter the blood stream.

Ovaries

• Found in females only.

• Produce the hormones Estrogen and Progesterone.

• These hormones are responsible for:

  • The Secondary Sexual Characteristics of a female
  • The regulation of the menstrual cycle.

Secondary Sexual Characteristics of a Female

• Development of Breasts
• Pubic & underarm hair growth

Testes

• They make the hormones called testosterone.

• Testosterone is responsible for the male's secondary sexual characteristics:

  • Deepening of your voice
  • Pubic hair

• Athletes take more testosterone to increase and enhance their performance.

Pancreas

• Secretes pancreatic juices:

  • Pancreatic Amylase
  • Pancreatic Lipase
  • Trypsin

• Has a duct.

• Pancreas is both an Exocrine Gland (has a pancreatic duct) and an endocrine gland.

• Secretes insulin - converts excess glucose into insoluble glycogen and stored in the liver and large muscles.

• Secretes Glucargon - converts glycogen back to soluble glucose. Cells can now use the glucose for respiration.

Pituitary Gland/Master Gland

• Secretes ADH - responsible for osmoregulation, makes walls of collecting duct permeable.
• Secretes Thyroid Stimulating Hormone (TSH) - has an effect on the thyroid gland, produces thyroxine.
• Secretes Growth Hormone (GH) - controls and stimulates growth of entire body/organism.
• Secretes Follicle Stimulating Hormone (FSH) - development of egg and sperms.
• Secretes Luteinizing Hormone (LH) - controls ovulation.
• Known as Master Gland - secretes many hormones which have an effect on many different organs.

Thyroid Gland

• Secretes Thyroxine - responsible for brain development, controls tissue respiration and growth regulation.

Adrenal Gland

• Produce a hormone called Adrenaline (Fight or Flight Hormone)

  • Causes increase Blood Flow (increased heart rate) - more energy
  • Increases respiratory rate
  • Pupils dilate - to see more.

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