Hormone Actions SC.912.L.14.31

Essential Question How do hormones work?

Hormones Chemicals secreted into blood Steroids or proteins Act on only on distant target organs that have receptors for the hormone Act until they are cleared from the blood by liver or kidney.

Lipid Soluble Hormones Type of Receptor Intracellular receptors (cytoplasm and/or nucleus) Types of hormones Steroids and thyroid hormones Action in cell Alters gene expression Examples: Estrogen, Testosterone, Thyroid Hormone, Aldosterone, Cortisol

Water Soluble Type of Receptor Types of hormones Action in Cell Cell surface receptors (plasma membrane) Types of hormones Proteins and peptides, catecholamines and eicosanoids Action in Cell Generation of second messengers which alter the activity of other molecules - usually enzymes - within the cell Examples: ADH, FSH, TSH, Epinephrine, Insulin

Mechanism of action of hormones Membrane permeability Protein synthesis Deactivation /activation of enzymes Secretory activity triggered Cell division stimulated Action depends on Level of circulating hormone # of receptors Affinity of receptors

Negative Feedback Most hormones are controlled by negative feedback. As the hormone brings the body back into balance less of it is produced.

Through another protein Day 2 - Hormones Fat Soluble Inside Cell Direct Water Soluble Outside cell Through another protein From your cornell notes complete this concept map.

Day 2 - From your cornell notes complete this concept map. Hormones ______Soluble _________ _____________ ______________ ________________ From your cornell notes complete this concept map.