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

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

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

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

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.

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

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

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

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.

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.

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)

Homework Pg 395 #2, 5, 8, 10