ENDOCRINE SYSTEM

Diabetes Mellitus - low insulin production

Hirsutism- High Androgens (male hormones)

Gigantism and Dwarfism - Growth Hormone

Goitre- Thyroid gland-Thyroxin (iodine)

Proptosis- Hyperthyroidism-increased thyroxin

Addison’s disease- Adrenal gland (glucocorticoids)

Cushing’s Disease- high cortisol hormone

Series of glands that produce hormones to help maintain homeostasis. Hormones: Chemical regulators that affect target cells in other parts of the body. Insulin Growth Hormone Testosterone

Some glands produce one hormone, some produce many kinds and even other chemicals. All hormones are transmitted by blood to target cells which have hormone specific receptor sites

HORMONES To be susceptible to the effects of a hormone, a cell must have a specific receptor . 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

Mechanism of Action Steroid Hormones (LIPID Soluble): hormones diffuse out of blood stream and into the target cells Cross target cell membranes to combine with receptor molecules in cytosol hormone-receptor complex activates a gene, initiating transcription and protein synthesis.

Mechanism of Action PROTEIN Hormones (WATER Soluble): hormones diffuse throughout of blood stream attach to receptors on the membrane of target cells the receptor-hormone complex activates a series of reactions within target cells to turn on genes Target cells begin their specific cellular functions.

Hormones and Feedback Mechanisms One gland responds to a stimulus to produce a hormone (A) This hormone stimulates a second gland to produce other hormone(s) (B) to generate homeostatic responses. The second hormone (B) also inhibits the hormone production of the original gland.