Ch16 Endocrine part 2 several separate organs release hormones into capillaries hormones are transported in the blood Hypothalamus Pituitary glands Pineal gland Thyroid Parathyroid Thymus Adrenal Cortex Adrenal Medulla Kidney Pancreas Ovary Testes several others for each hormone know: it s effects, functions what stim its release where is it made its target organs Endocrine system Endocrine Glands learning goals direct hormones tropic hormones pre-hormone types of hormones target = non-endocrine tissues target = other endocrine glands inactive form metabolic hormones - thyroid hormones thyroid hormone thyroid gland (follicular cells) thyroxine T 4 tri-iodothyronine T 3 effects: calorigenic basal metabolic rate (BMR) - heat rate of cell respiration uncoupling enzymes metabolic protein synthesis increase heart rate and BP growth nervous system, muscle, skeletal control of T 4 production TSH (thyroid stimulating hormone) low blood T 4 low body temp pregnancy inhibited by high blood T 4 somatostatin follicular cells produce thyroid hormones follicles store pre-hormone = colloid Thyroid gland anatomy parafollicular cells produce calcitonin
thyroglobulin synthesis iodination I 2 added to tyrosines storage colloid = thyroglobulin + I 2 cleavage colloid splits into T 4 and T 3 secretion exocytosis Thyroid hormone synthesis transport TBG thyroxine-binding globulin calcitonin effects: thyroid gland (parafollicular cells) decrease blood calcium deposit calcium into bone high blood calcium calcium hormones parathyroid hormone parathyroid gland effects : hypercalcemia increase Ca ++ absorption increase Ca ++ reabsorption remove Ca ++ from bone low blood calcium adrenal cortex outer layers glucocorticoids cortisol mineralcorticoids aldosterone androgens Adrenal gland adrenal medulla catecholamines inner layer epinephrine, norepinephrine stress hormones - epinephrine epinephrine, norepinephrine catecholamines made in adrenal medulla effects: fight or flight adrenaline rush increase heart rate, BP increase respiratory rate ; bronchodilation increase blood to muscles increase alertness increase blood glucose Sympathetic nervous system stress hormones - cortisol cortisol (glucocorticoid) the stress hormone made in adrenal cortex increase blood glucose for brain = glucose sparing glucose from glycogen glycogenolysis glucose from fats gluconeogenesis increase BP protein catabolism more AA for repair anti-inflammatory limits immune response anti sex hormones affects memory ACTH stress
aldosterone (mineralcorticoid) adrenal cortex increases Osm Na + in blood increases Na + reabsorption from nephron, intestines increases BP targets: nephron ; intestines angiotensin low blood Na atrial natriuretic peptide heart decreases Osm Na + in blood decreases BP high BP osmolarity Antidiuretic hormone (ADH) hypothalamus effects: decreases blood Osm increases water reabsorption nephron increases blood volume, BP high osmolarity insulin pancreas beta (β) cells the most anabolic hormone increase membrane transport of glucose increase cell respiration increase storage of glucose, glycogen increase protein synthesis increase lipid synthesis high blood glucose parasympathetic n.s. glucagon glucose enters beta cells increases cell respiration ATP closes K + channels depolarization opens Ca ++ channels Ca ++ stim exocytosis of insulin hormone to decrease blood glucose GLUT4 carrier Insulin production hormones to increase blood glucose glucagon pancreas alpha (α) cells affects liver - glycogenolysis, gluconeogenesis low blood glucose, eg. between meals other hormones: epinephrine for N.S. if immediate stress cortisol for N.S. if long term stress growth hormone for growth thyroxine for cell respiration, heat Diabetes Mellitus hyperglycemia = high blood glucose Diabetes Mellitus chronic hyperglycemia type 1 Insulin dependent IDDM decreased Beta cells congenital or autoimmune type 2 non Insulin dependent NIDDM decrease Insulin receptors on target cells developed common symptoms glucosuria polyuria polydipsia polyphagia
same as GHIH inhibit GH (growth hormone) inhibit TSH (thyroxine) inhibit insulin inhibit gastric activity renin-angiotensin epinephrine cortisol thyroxine antidiuretic hormone somatostatin BP hormones atrial natriuretic peptide lowers BP renin-angiotensin-aldosterone system maintains (raises) systemic BP renin made by kidney if low BP renin stim angiotensinogen angiotensin I (liver) ACE stim angiotensin I angiotensin II (lung) angiotensin II vasoconstriction systemic BP aldosterone RAAS increases protein synthesis: thyroid hormone growth hormone insulin insulin-like growth factors protein synthesis decreases protein synthesis growth hormone insulin-like growth factors thyroid hormone cortisol anterior pituitary liver thyroid gland growth related hormones estradiol progesterone follicle (ovary) corpus luteum (ovary) sex hormones testosterone interstitial cells inhibin sustentacular cells androgens made in adrenal cortex converted to estrogen or testosterone hormones w/other functions anti-inflammatory cortisol adrenal cortex RBC production erythropoietin kidney uterine contractions oxytocin hypothalamus milk release oxytocin milk production prolactin anterior pituitary Vit D production calcitriol kidney cholecalciferol skin inhibit RAS melatonin digestive functions gastrin stomach secretin small intestine cholecystokinin small intestine hunger control leptin adipose
hormones that control other endocrine glands stimulating hormones anterior pituitary control other endocrine glands stimulate growth of gland + hormone production releasing hormones control the anterior pituitary hypothalamus Hypothalamus Pituitary gland relationship master gland of the endocrine system posterior pituitary is a neural extension of the hypothalamus hypothalamic-hypophyseal tract 2 hormones are made in the hypothalamus, released from the posterior pituitary : antidiuretic hormone ADH oxytocin anterior pituitary is controlled by releasing hormones (RH) from the hypothalamus via the hypophyseal portal system anterior pituitary secretes : direct hormones stimulating hormones Anterior Pituitary direct hormones GH growth hormone = somatotropic hormone effects: mitosis protein synthesis increase blood glucose insulin-like growth factors stim: GHRH ; low GH ; exercise inhibited by GHIH = somatostatin PRL prolactin effect: milk production stim PRH ; nursing LH luteinizing hormone effect: ovulation Anterior Pituitary stimulating hormones TSH thyroid stimulating hormone thyrotropin ACTH adrenocorticotropic hormone corticotropin FSH follicle stimulating hormone folliculotropin LH luteinizing hormone luteotropin ICSH interstitial cell stimulating hormone GH somatotropin stimulate target tissue to release hormone ; grow stimulating hormone effects ant pituitary other endocrine glands TSH thyroid thyroxine ACTH adrenal cortex cortisol FSH follicle estrogen LH corpus luteum progesterone ICSH interstitial cells testosterone GH liver insulin-like growth factors
hypothalamus controls the anterior pituitary there is a regulating hormone for every pituitary hormone hypothalamus ant. pituitary hormone growth hormonerh GHRH GH prolactin RH PRH PRL corticotropicrh CRH ACTH thyrotropicrh TRH TSH gonadotropicrh GnRH (FHRH) FSH GnRH (LHRH) LH growth hormoneih GHIH inhibit GH gonadotropicih GnIH inhibit FSH, LH private controls the general Who s the Boss? target gland hormones inhibit the hypothalamus and/or anterior pituitary negative feedback hormone related diseases Grave s Disease hyperthyroidism Cretinism hypothyroidism (congenital) Goiter thyroid tumor due to decreased I 2 Cushing s increased Cortisol Addison s Disease decreased Aldosterone, Cortisol Gigantism increased GH (congenital) Acromegaly increased GH (adult) Pituitary Dwarfism decreased GH Diabetes Mellitus high blood glucose ; insulin