Hormones &The Endocrine Glands

10.1 & 10.2

Hormones

• chemicals produced by cells in one part of the body that regulate processes in another part of the body

• endocrine glands secrete hormones directly into the blood (exocrine glands into ducts)

Endocrine vs. Nervous

• both systems integrate and control organs and tissues

• nervous system helps body to adjust quickly to changes

• endocrine system maintains control over longer periods of time

Types of hormones

• protein hormones are amino acid chains and are water-soluble; diffuse well through blood and fluids

• steroid hormones are derived from cholesterol and are soluble in blood when combined with hydrophilic carrier proteins

Water-Soluble Hormones

Animation…

• Narrated animation of water-soluble (protein) hormones. Specific example of using cAMP to activate proteins in the target cell:

• http://highered.mcgraw-hill.com/sites/0072943696/student_view0/chapter10/animation__second_messenger__camp.html

Fat-Soluble Hormones

Animation…

• Narrated animation of steroid hormone action:

• http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120109/bio46.swf::Mechanism%20of%20Steroid%20Hormone%20Action

Hypothalamus

• part of the nervous system

• produces neurohormones which diffuse into the blood and travel to the pituitary gland

Pituitary Gland

• “master gland”

• secretes hormones that control other endocrine glands

• under the nervous control of the hypothalamus

Pituitary Gland

Anterior Pituitary

• neurohormones from the hypothalamus stimulate or inhibit release of hormones

• produces, stores & releases:– prolactin (PSH)– growth hormone– tropic hormones (TSH, ACTH, FSH, LH) – melanocyte-stimulating hormone MSH

“Intermediate Lobe”

• not very developed in humans

• releases endorphins, “natural painkillers”

• endorphins function in the nervous system in pathways that control pain)

Posterior Pituitary

• stores and releases hormones produced by the hypothalamus:– anti-diuretic hormone (ADH)– oxytocin