1. The Glands and Hormones of the Endocrine System
Chapter 9.1
McGraw-Hill Ryerson
Biology 12 (2011)

2. ENDOCRINE SYSTEM Insulin Growth Hormone Gastrin
Series of glands that produce hormones to help maintain homeostasis.
Hormones: Chemical regulators that affect other parts of the body.
Insulin
Growth Hormone
Gastrin

3. Hormones
Some glands produce one hormone, some produce many kinds and even other chemicals.
Hormones must be produced and travel through the blood to a target cell or organ.
Levels of hormones vary throughout the day.
Difference between hormone and neurotransmitter
Hormone travels through blood stream to reach another cell
Neurotransmitter travels across synapse to neighbouring cell

4. Coordination
The nervous system and the endocrine system work together to allow the body to function.
Nervous System --> SHORT TERM corrections
Endocrine System --> LONG TERM stability

5. HORMONES Sex hormones, cortisol Insulin, growth hormone
Two types of hormones:
Steroid hormones: made from cholesterol, complex ring structures, fat soluble
Sex hormones, cortisol
Protein hormones: amino acid chains
Insulin, growth hormone
To be susceptible to the effects of a hormone, a cell must have a specific receptor.

6. Mechanism of Action: Steroid Hormones
hormones diffuse out of blood stream and into the target cells
combine with receptor molecules in cytoplasm

7. Mechanism of Action: Steroid Hormones
hormone-receptor complex diffuses into nucleus
attaches to chromosomes and activates a gene, initiating transcription and protein synthesis.

8. Mechanism of Action: Protein Hormones
hormones diffuse out of blood stream
attach to receptors on the cell membranes of target cells

9. Mechanism of Action: Protein Hormones
the receptor-hormone complex activates the production of enzyme that converts ATP into cyclic AMP (cAMP)
cAMP is a messenger that activates various enzymes inside the cell to begin their normal functions.

10. PITUITARY GLAND
This is known as the master gland because it controls a lot of other endocrine glands.
A small sac connected to the hypothalamus.
Pituitary gland stores hormones while the hypothalamus stimulates it to release them.

11. PITUITARY GLAND The pituitary gland has two lobes:
The posterior lobe stores and releases hormones produced by the hypothalamus (ex. ADH, oxytocin)
The anterior lobe produces and stores its own hormones (ex. TSH, prolactin)

12. Homework
Pg 395 #2, 5, 8, 10