* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download endocrine
Survey
Document related concepts
Triclocarban wikipedia , lookup
Menstrual cycle wikipedia , lookup
Xenoestrogen wikipedia , lookup
Cardiac physiology wikipedia , lookup
History of catecholamine research wikipedia , lookup
Neuroendocrine tumor wikipedia , lookup
Hormone replacement therapy (male-to-female) wikipedia , lookup
Mammary gland wikipedia , lookup
Breast development wikipedia , lookup
Congenital adrenal hyperplasia due to 21-hydroxylase deficiency wikipedia , lookup
Endocrine disruptor wikipedia , lookup
Bioidentical hormone replacement therapy wikipedia , lookup
Hyperthyroidism wikipedia , lookup
Graves' disease wikipedia , lookup
Hyperandrogenism wikipedia , lookup
Transcript
The Endocrine System chapter 16 Endocrine System: Definitions • Endocrine – releasing substances into blood – Endo = within or internal – Contrast with Exocrine – releasing substances outside the body • Hormone – a chemical that influences the function of a remote tissue (acts at a distance) Endocrine System: Overview 9 glands in total Endocrine glands 1. pituitary 2. thyroid 3. parathyroid 4. adrenal 5. pineal 6. thymus Mixed glands A. produce both hormones and exocrine products 1. pancreas 2. gonads B. produce hormones and has neural functions 1. hypothalamus Pineal gland Hypothalamus Pituitary gland Thyroid gland Parathyroid glands (on dorsal aspect of thyroid gland) Thymus gland Adrenal glands Pancreas Ovary (female) Testis (male) Hormones • How they work – Regulate the metabolic function of other cells – Have lag times ranging from seconds to hours – Tend to have prolonged effects – Are classified as amino acid-based hormones, or steroids 2 Main Types of Hormones • Amino acid based – Water-soluble – Do not enter the cell – e.g., insulin, norepinepherine, epinephrine • Steroids – Lipid soluble – Act intracellularly and activate genes – e.g., testosterone, estrogen, cortisol Mechanism of Hormone Action • Act on receptors in the plasma membrane • Amino acid–based hormones – e.g., epinephrine- binds to smooth muscle cells in blood vessels - causing contraction • Direct gene activation • Steroid hormones, thyroid hormones – e.g., growth hormone - stimulates cells to increase in size and divide • The precise response depends on the type of the target cell • The ONLY tissue to respond is the Target Tissue (may be very specific (1) tissue, or multiple tissues) Hormone Blood Concentrations • Concentrations of circulating hormone reflect: – Rate of release – Speed of inactivation and removal from the body • Hormones are removed from the blood by: • Degrading enzymes • The kidneys • Liver enzyme systems Hypothalamic Control • Hypothalamus “releasing hormones” and “inhibiting hormones” tells of central control by brain – GHRH (growth hormone RH) and GHIH (growth hormone IH) control GH from Ant. Pituitary – PRH (prolactin RH) and PIH control PL from Ant. Pit. – TRH thyrotropin RH – release of TSH from Ant. Pit. – CRH corticotropin releasing hormone – release of hormones from adrenal cortex Stress – GnRH gonadotropin RH – release of gonadal hormones from Ant. Pit. LH and FSH Pituitary (Hypophysis) • Pituitary gland – two-lobes – secretes 9 major hormones • Connected to the hypothamus by – Posterior Lobe • Neurohypophysis – neural tissue) and the infundibulum • Receives, stores, and releases hormones from the hypothalamus – Anterior Lobe • Adenohypophysis – made up of glandular tissue • Synthesizes and secretes a number of hormones Pituitary (Hypophysis) Figure 16.6 Anterior Pituitary Hormones • regulate other endocrine glands • • • • • • GH – growth hormone TSH – thyroid stimulating hormone ACTH – adrenocorticotrophic hormone FSH – follicle stimulating hormone LH – luteinizing hormone PRL - prolactin (latter 3 are called gonadotropins) Growth Hormone (GH) • Underproduction in children dwarfism • Overproduction in children gigantism • Overproduction in adults acromegaly Posterior Pituitary Hormones • Posterior pituitary – stores antidiuretic hormone (ADH) and oxytocin – ADH and oxytocin are synthesized in the hypothalamus • Oxytocin stimulates smooth muscle contraction in breasts and uterus – “cuddle hormone” • Both are amino acid based – Receptor location? Pancreas • both exocrine and endocrine cells, • Acinar cells enzyme-rich juice used for digestion (exocrine product) • Pancreatic islets (islets of Langerhans) produce hormones (endocrine products) • The islets contain two major cell types: – Alpha () cells that produce glucagon – Beta () cells that produce insulin Regulation of Blood Glucose Levels • hyperglycemic glucagon glucose uptake • hypoglycemic insulin glucose release Figure 16.18 Diabetes Mellitus (DM) • Results from hyposecretion or hypoactivity of insulin • The three cardinal signs of DM are: – Polyuria – huge urine output – Polydipsia – excessive thirst – Polyphagia – excessive hunger and food consumption Thyroid Gland • thyroid hormone metabolism, BP, growth – T3 (10x) – T4 • calcitonin response to rising blood calcium – inhibit gut absorption and kidney reabsorption of Ca++ Thyroid Disorders • Hypothyroidism – Thyroid gland defect, inadequate TSH, lack of iodine • Low metabolic rate, feeling chilled • Goiter formation ( if cause is lack of iodine) • Cretinism = Hypothyroidism in infants • Stunted growth, low mentality • can be prevented by hormone replacement therapy Grave’s Disease – Hyperthyroidism • Autoimmune disease- body attacks and stimulates the thyroid cells - increased thyroid hormone • High BMR, Weight loss, Increased heart rate, Protrusion of the eyeballs, goiter – Treated by surgical removal of the thyroid gland Parathyroid Glands • PTH (parathormone) – response to falling calcium in blood – promotes gut absorption and kidney reabsorption of Ca++ – Question: • what two hormones regulate calcium in blood? Adrenal (Suprarenal) Glands • Adrenal glands – cope with stressful events • Structurally and functionally, they are two glands in one – Adrenal cortex – glandular tissue – Adrenal medulla – neural tissue that acts as part of the SNS Adrenal Cortex Hormones • Aldosterone - dehydration – causes kidney to reabsorb Na+ reabsorb water – stimulated by angiotensin (remember Renin) • Cortisol - stress – increases blood glucose levels & reduces edema of tissues – prolonged high levels changes in neural and circulatory function, depressed bone/cartilage growth, suppressed immune response Adrenal Cortex Hormones • Androgens (masculinizing hormones) – most important is testosterone • the onset of puberty • secondary sex characteristics • sex drive in females – testosterone can be converted to estrogen in females after menopause Disorder • Addison’s disease – Hyposecretion of the adrenal cortex • Deficiency in cortisol and aldosterone • Low BP • Hypoglycemia • Cushings disease – Hypersecretion of adrenal cortex (tumor of the adrenal cortex) • Hyperglycemia • “buffalo hump” (fat on upper back) Adrenal Medulla • secretes the catecholamines – epinephrine – norepinephrine • “Fight or Flight” secretion causes: – blood glucose levels to rise – blood vessels to constrict – faster heart rate – blood diversion to brain, heart, and skeletal muscle Adrenal Medulla • Epinephrine is the more potent stimulator of the heart and metabolic activities • Norepinephrine is more influential on peripheral vasoconstriction and blood pressure Stress and the Adrenal Gland Figure 16.16