Endocrine organs and Disorders

Pituitary Gland Lies deep in brain, attached to hypothalmus Anterior pituitary – adenohypophysis (gland) Tropic hormones – stimulates another endocrine gland to secrete hormone Thyroid stimulating hormone (TSH)– thyroid Adrenocorticotropic hormone –(ACTH) adrenal cortex Follicle-stimulating hormone (FSH) – ovarian follicles Luteinizing Hormone (LH)- ovulating hormone Growth hormone – promotes normal growth Prolactin – lactogenic hormone (breast development for lactation)

Disorders of AP Growth hormone Prolactin Hypersecretion – gigantism, Acromegaly, hyperglycemia Hyposecretion – dwarfism Prolactin Hyper – inappropriate lactation in men and non-nursing women Hypo – insufficient lactation in nursing women

Posterior pituitary Antidiuretic hormone (ADH) – reabsorption of water from urine in kidney to blood, decrease urine volume Oxytocin – stimulates contraction of smooth muscle of uterus, initiate and maintain labor, stimulates milk letdown

Disorders of PP ADH Oxytocin Hyper – abnormal water retention Hypo – diabetes insipidus – elimination of too much urine – dehydration Oxytocin Hyper – increase milk flow Hypo – prolonged labor

Hypothalmus Produces ADH and oxytocin (PP only releases them) Releasing hormones – stimulates Anterior pituitary to release hormones Inhibiting hormones – Inhibits anterior pit. release of hormones Hypothalmus functions in nervous and endocrine systems – dominant role in regulation of many body functions: body temp, appetite, thirst

Thyroid Thyroxine (T4) and Triiodothyronine (T3) – speed up cells release of energy from foods, stimulate cellular metabolism Calcitonin – maintains homeostasis of blood calcium, decreases the amount of calcium in the blood, act on bone to inhibit its breakdown, therefore calcium does not move out of bone.

Thyroid disorders Hyperthyroidism, increase metabolic rate, lose weight, restless, excessively active Exophthalmus – protruding eyes Graves disease – inherited, hyperthyroidism, bulging eyes Hypothyroidism – under secretion of TH Goiter – low intake of iodine, enlargement of thyroid to compensate for lack of iodine Cretinism – low metabolic rate, retarded growth and sexual development Myxedema – lessened mental and physical vigor, weight gain, loss of hair, accumulation of mucous fluid (eyes)

Parathyroid glands Posterior of thyroid, Usually 4, small parathyroid hormone – increase concentration of calcium in blood (opposite of calcitonin) fig. 11-12 Hyper – hypercalcemia Hypo - hypocalcemia

Adrenal Glands – top of kidneys Adrenal cortex – outer part, corticoids Mineralocorticoids, MC’s – aldosterone Control mineral salts in blood (increase sodium, decrease potassium) Glucocorticoids (cortisol, hydrocortisone) Maintain normal glucose concentration and blood pressure Sex hormones

Adrenal Medulla Inner portion of adrenal gland Epinephrine, Norepinephrine – secreted during stressful situations, works with sympathetic nervous system (adrenaline)

Adrenal disorders Hypersecretion of GC’s – usually because of a tumor – Cushing syndrome Moon face, buffalo bump due to redistribution of body fat, can remove tumor Hypersecretion in inner zone – sex hormones called androgens, results in secondary sex characteristics In women, caused by virilizing tumor Hyposecretion of adrenal cortex - Addison disease – muscle weakness, low blood sugar

Pancreatic islets – islets of Langerhans Scattered among pancreatic cells in pancreas Glucagon – increases the blood glucose concentration Insulin – decreases blood glucose concentration by moving it out of the blood Hypersecretion - hypoglycemia Hyposecretion - type 1 diabetes mellitus – high glucose levels in blood Type 2 diabetes – abnormality of insulin receptors

Additional endocrine glands Ovary Ovarian follicles – estrogen, feminizing hormone Corpus luteum – progesterone Testes Testosterone – masculinizing hormone Thymus – in mediastinum, contains WBC’s Thymosin – several hormones that play in important role in the development and function of the body’s immune system

More endocrine glands… Placenta – temporarily produce hormones Chorionic ganadotropins (pregnancy test indicators), estrogen, progesterone Pineal gland – near 3rd ventricle in brain Melatonin – regulates puberty and menstrual cycle in females 3rd eye – optic nerve, increase at night, internal clock and sleep cycle, supplements help to sleep SAD – seasonal affective disorder – high levels