Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Breast development wikipedia , lookup
Hormonal contraception wikipedia , lookup
Mammary gland wikipedia , lookup
Hyperandrogenism wikipedia , lookup
Menstrual cycle wikipedia , lookup
Neuroendocrine tumor wikipedia , lookup
Endocrine disruptor wikipedia , lookup
Triclocarban wikipedia , lookup
Adrenal gland wikipedia , lookup
Hormones and homeostasis ?Hormones ?Homeostasis Name some endocrine glands Hormones versus neurotransmitters… Hormones can be steroids, proteins or tyrosine derivatives (amines) Steroid hormones • • • • Derivatives of cholesterol Insoluble in water – travel in plasma bound to plasma proteins Longer-acting and act INSIDE the cell Stress, sexuality, SEX Steroid hormones • Steroid hormones pass through the cell membrane easily and act on the inside of the cell • Intracellular effects • Bind to receptors in cytoplasm OR nucleus • Steroid hormones alter DNA transcription: they act as ‘transcription factors’… Steroid hormones are transcription factors Amine hormones • Derived from the amino acids tyrosine, tryptophan, glutamine • Produced by - the adrenal gland, brain, hypothalamus and the anterior pituitary gland • Catecholamines have very short duration of action – act as neurotransmitters as well as hormones Melatonin (tryptophan derivative) Serotonin (Glutamine derivative) Peptide/ protein hormones (there are many!) Peptide and protein hormones • Soluble in plasma but cannot cross the lipid membrane • Act on cell surface receptors • Binding with the receptor leads to activation of a ‘second messenger’ cascade • May or may not affect transcription in the nucleus Protein hormones act via ‘second messengers’ In summary…. Hormonal control The hypothalamus and the pituitary gland are closely related The hypothalamus links the nervous and the endocrine system • Hypothalamus controls synthesis and release of MANY hormones from the anterior pituitary (via releasing factors and portal circulation) • Hypothalamic neurosecretory cells release hormones (oxytocin, ADH) from the posterior pituitary gland • Negative feedback plays a major role Hypophyseal portal circulation Hormones secreted by the hypothalamus/pituitary… How does the hypothalamus orchestrate the autonomic nervous/endocrine system? Negative feedback is essential to hypothalamo-pituitary-hormonal control • Hormones whose secretion is regulated by the hypothalamus and pituitary gland regulate their own release through negative feedback. • The hormone produced by a peripheral glad will bind to receptors in the hypothalamus and pituitary and inhibit release of ‘tropic’ hormones’ Explain the control of ADH secretion by negative feedback Thyroid hormone release is controlled by negative feedback…