Hormones

• Hormones are chemical messengers that travel in the blood to activate target cells
• They are carried in the blood plasma to other parts of the body, but they only affect target cells
• They are released directly into the blood
• Hormones are secreted by various glands
• Hormones tend to have long-lasting effects
• They travel at the "speed of blood"

Glands

The Pituitary Gland

• secretes many important hormones…