BIO 446L 1st Edition Lecture 18 Outline of Last Lecture I. Exam 2 review dayOutline of Current Lecture I. The endocrine systema. Pituitary glandi. Hypothalamusii. Anterior pituitaryiii. Posterior pituitaryiv. Adrenal cortexCurrent LectureThe Endocrine System- Hormoneso Classifications Peptide, amino acid derivatives, or lipids (steroids)o DNES= diffuse neuro endocrine secretory cells Secrete hormones individually, often in paracrine manner (tissues nearby)o Make a chart of hormones, chemical class, gland, action- Pituitary glando Sits in sella turcica of sphenoid bone of skullo Posterior pituitary is an extension of the hypothalamus Derived as down pocketing of brain in embryonic developmento Anterior pituitary—adenohypophysis Derived as up pocketing of rood of mouth Pars intermedia—between ant and post Pars distalis—stalk connecting anterior pituitary to hypothalamus- Hypothalamic hormones—table 20.2o Arteries arterioles 1st capillary bed venuole vein 2nd capillary bed Hormones diffuse receptors of anterior pituitaryo Hypothalamal hypophyseal tract (bundle of CNS axons) In posterior pituitaryo 2 nuclei of hypothalamus Paraventricular nuclei—produce oxytocinThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. Supraoptic nuclei—produce ADH (receptor in kidney—water retention)- Axons move down stalk and terminate in posterior pituitary—NO secretory cells in posterior pituitary (secreted from axons from hypothalamus)- Anterior Pituitary—Pars distaliso Major secretory structure of anterior pituitaryo Table 20.1—ACTH, TSH, FSH/LH, GH (somatotropin), prolactino Acetophils—red, basophils—blue, chromophobe—poor staino Round, plump cells—will secrete hormoneso Very large blood vessels—sinusoid fenestrations (slits)o ACTH adrenal cortex POMC- P= pro hormone- O= Opio—beta endorphin- M= Malanocytes—MSH, melatonin of skin/eyes/haur- C= ACTHo TSH= thyroido FSH/LH= gonadotropinso GH= growth hormone (somatotropin—not trophic)o Prolactin= not trophic, milk production in breast- Anterior pit—Target Tissue and Feedbacko Negative feedback Upon stimulation, hypothalamus will release a trophic hormone which will cause the release of another hormone then to the target tissue- Levels of these hormones are sensed and if too high or too low, will feedback to hypothalamus to reverse signal and regulate levelso Know target tissue for hormones of anterior pit- Posterior Pituitary—Pars Nervosao Pituocytes—like glial cells, support nerve tissueo Neurosecretory bodies—bulges off axon that store hormones secreted by axons when action potential fired from hypothalamic nuclei, hormone is releasedo Oxytocino ADH (aka vasopressin)- Adrenal Cortexo Adrenal glands sit on top of kidneys—cortex and medullao Cortex Cell layers- Zona glomerulosa—secretes mineralocorticoido Aldosterone—increases Na absorptiono Stimulus is angiotensin II (primary) and ACTH (weak) - Zona fasiculata—secrete glucocorticoidso Cortisol—stress hormone, increases blood glucose levels and blunts inflammatory responseo Stimulus is ACTH- Zona reticularis—secretes androgens (weak) and dehydroepiantrosteroneo Stimulus is ACTH cells that don’t stain—lipids/steroid hormones see slide for micrographs of each layer MA: cushing disease—over secretion of cortisol, fat pocket deposition MA: Adison disease—darkened skin on face MA: long term steroid use—inhibits body’s own natural production of
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