The Endocrine System -the 2 nd in control-

The Endocrine System Composed of several ductless glands –Pituitary (anterior & posterior) –Thyroid –Adrenal/ Supraranal –Pineal –Thymus –ALONG w/ the Pancreas, Placenta & Gonads

endo= within & crine=to secrete Made of glands Secrete hormone directly into bloodstream (ductless glands) Specialized epithelial tissue >12.5g Endocrine

Hormones (hormon = excite) –Chemical messengers released into the blood & lymph for transport around the body –Long lasting effect –Effect target cells or organs

Hormone Function reproduction growth & development mobilization of body defenses cellular metabolism & homeostasis

6 Mechanisms of hormone release (a) Humoral: in response to changing levels of ions or nutrients in the blood (b) Neural: stimulation by nerves (c) Hormonal: stimulation received from other hormones

Hormone Control Negative Feedback 1.Blood level of hormone falls 2.Brain gets message & sends out hormone to stimulate gland 3.Gland secretes hormone 4.When blood level of hormone increases, then brain hormone stops

Hypothalamus Anterior pituitary Posterior pituitary Thyrotropin ACTH Somatotropin LH FSH Prolactin Vasopressin Oxytocin Thyroid Adrenal Cortex Adrenal Medulla PancreasOvary Testis Muscles liver Tissues Liver, muscles Estradiol Testosterone Insulin, glucagon, somatostatin T3 Cortisol aldosterone Mammary glands Reproductive organs Epinephrine Releasing hormones Nervous

Pituitary Gland

Anterior Pituitary I Growth Hormone stimulates body to grow & burn carbohydrates (sugars) & fat Dwarfism hyposecretion Gigantism hypersecretion

Anterior Pituitary II Melanocyte-stimulating Hormone increases amount of pigmentation in skin Prolactin stimulates milk production and maintains it Adrenocorticotropic Hormone controls the secretion of hormones from the adrenal cortex Thyroid Stimulating Hormone controls the release of hormones from the thyroid gland

Anterior Pituitary III Follicle-Stimulating Hormone stimulates development of ova and estrogen production in ovaries; stimulates sperm production Lutenizing Hormone stimulates ovulation and prepares uterus for possible implantation of fertilized ovum; stimulates the production of testosterone

Posterior Pituitary Oxytocin stimulates contraction of uterus & of the cells surrounding the mammary glands Antidiuretic hormone regulates fluid balance by reabsorbing water in the kidneys; also helps to regulate blood pressure

Thyroid Gland Thyroxine & Triiodothyronine stimulates metabolism; promotes protein synthesis, glucose uptake and lipid metabolism; is regulated by TSH Calcitonin reduces Ca and P levels in blood;

Thyroid Disorders Cretinism Hyposecretion (children) Myxedema Hyposecretion (adults) Graves’ Disease hypersecretion Goiter

Adrenal or Suprarenal Glands (adrenal cortex)- glands on top of kidneys Aldosterone maintains fluid balance by conserving Na and excretion of K; cause water retention and increased blood pressure Cortisol promotes glucogenesis in liver; inhibits allergic response and reduces inflammation Androgens and Estrogens sex hormones

Adrenal or Suprarenal Glands (adrenal cortex) disorders Cushion’s Disease Androgenital syndrome

Adrenal or Suprarenal Glands (Adrenal Medulla) epinephrine & norepinephrine copy effects of the sympathetic nervous system

Pancreas Glucagon stimulates conversion of glycogen to glucose Insulin stimulates conversion of glucose to glycogen; stimulates uptake of glucose by muscle and nerve cells Diabetes Mellitus –Hypo/hyper secretion of insulin

Pineal Gland Melatonin regulates diurnal biorhythms; highest at night

Thymus Gland Thymosin stimulates the production of T-cells

Gonads Ovaries - Estrogens stimulates development of sex organs and secondary sex characteristics Testes -Testosterone stimulates development of sex organs and secondary sex characteristics

Placenta Human Chorionic Gonadotropin stimulates production of estrogen and progesterone during pregnancy Human Placental Lactogen prepare breasts for milk production Relaxin loosens mother's pelvic ligaments and pubic symphysis

Endocrine System…. Professor KS Satyapal 20 ENDOCRINE DISORDERS GIGANTISM: Hyperactive pituitary in preadolescence Overgrowth of long bones

Endocrine System…. Professor KS Satyapal 20 ENDOCRINE DISORDERS ACROMEGALY: Hyperactive pituitary in adulthood Over development of bones in face, hands, feet

Endocrine System…. Professor KS Satyapal 20 ENDOCRINE DISORDERS Dwarfism: Hypoactive pituitary in childhood

Endocrine System…. Professor KS Satyapal 22 ENDOCRINE DISORDERS GOITER Thyroid hyper secretion Enlarged thyroid gland due to iodine insufficiency

Endocrine System…. Professor KS Satyapal 2 1 ENDOCRINE DISORDERS CRETINISM Results from thyroid hormone insufficiency in infancy

Endocrine System…. Professor KS Satyapal 22 ENDOCRINE DISORDERS Grave’s Disease/Exophthalmos Hyperactive thyroid Bulging eyes

Endocrine System…. Professor KS Satyapal 22 ENDOCRINE DISORDERS Hypothyroidism Hypoactive thyroid

Endocrine System…. Professor KS Satyapal 23 ENDOCRINE DISORDERS CUSHING’S SYNDROME hypersecretion of adrenal cortex Adipose tissue accumulates in cheeks & base of neck

Endocrine System…. Professor KS Satyapal 23 ENDOCRINE DISORDERS Diabetes hyposecretion of insulin Untreated = hyperglycemia (too much sugar in blood) Overtreated = hypoglycemia (too little sugar in blood)