Endocrine System Health Science 1

Glands Gland- Hormones ENDOCRINE GLANDS -any organ that produces a secretion Hormones Chemical messengers ENDOCRINE GLANDS Secrete hormones directly into bloodstream Ductless  EXOCRINE GLANDS – secrete substances through a duct (sweat, salivary, lacrimal and pancreas)

Pituitary Gland Tiny structure the size of a grape Located at the base of the brain Posterior is connected to the hypothalamus (controls bp, beating of the heart, temp control, appetite,etc) Divided into anterior and posterior lobes The “Master Gland”

Pituitary Gland Anterior Pituitary Hormones: GROWTH HORMONE – GH responsible for growth and development PROLACTIN – develops breast tissue, stimulates production of milk after childbirth THYROID-STIMULATING HORMONE – TSH - stimulates thyroxine

Pituitary Gland Anterior Pituitary Hormones: ADRENOCORTICOTROPIC HORMONE – ACTH – stimulates adrenal cortex FOLLICLE-STIMULATING HORMONE – FSH - stimulates growth of graafian follicle and production of estrogen in females, sperm in males LUTEINIZING HORMONE – LH – stimulates ovulation and formation of corpus luteum, which produces progesterone in females

Pituitary Gland Posterior Pituitary Hormones: VASOPRESSIN – converts to ADH (antidiuretic hormone) in the bloodstream, acts on kidney to concentrate urine and preserve H2O in the body OXYTOCIN – released during childbirth causing contractions of the uterus

Thyroid Gland Butterfly-shaped mass of tissue On either side of larynx, over trachea H-shaped Main hormone – THYROXINE – is controlled by the secretion of TSH Thyroxine controls the rate of metabolism CALCITONIN – controls calcium ion concentration in the body, prevents hypercalcemia

Parathyroid Gland Four glands, each the size of a grain of rice Attached to posterior thyroid Produce PARATHORMONE which helps control blood calcium level, prevents hypocalcemia

Thymus Gland Posterior to the sternum Endocrine gland and lymphatic organ Located behind the sternum, above and in front of the heart Begins to disappear at puberty Important for immunity

Adrenal Glands Located above the kidney & divided into cortex and medulla. Adrenal cortex secretes hormones known at corticoids – they are anti-inflammatory ANDROGENS are male sex hormones Adrenal medulla(inside) secretes epinephrine (adrenalin) and norepinephrine ADRENALIN is a powerful cardiac stimulant – “fight or flight” hormones that prepare the body for an emergency situation

Gonads Ovary in female Testes in male Estrogen – development of female reproductive organs, secondary sex characteristics (may have underdeveloped breast, no menstrual cycle) Progesterone – plays a part in the menstrual cycle Testosterone – male reproductive organs and secondary sex characteristics

Pancreas Located behind the stomach Also organ of digestive system. Endocrine and exocrine functions Involved in production of INSULIN by special cells- ISLETS OF LANGERHANS Insulin – promotes utilization of glucose by the cells, fatty acid and amino acid transport, and facilitates protein synthesis

Hormones Prostaglandins- tissue hormones that can cause constriction of the blood vessels and muscle contractions Steroid abuse-liver changes, dec.spleen prod., atrophy of testicles, breast enlargement and increase cardiovascular disease.

Endocrine Disorders GIGANTISM Hyperfunction of pituitary – too much growth hormone In preadolescent – overgrowth of long bones leads to excessive tallness Cx- usually pituitary tumor Rx- remove tumor or medication to stop release of GH

Endocrine Disorders ACROMEGALY Hyperfunction of pituitary – too much growth hormone in adulthood Overdevelopment of bones in face, hands and feet Attacks cartilage – so the chin protrudes, lips nose and extremities enlarge Rx – drugs to inhibit growth hormone, radiation

Endocrine Disorders Growth Hormone Deficiency S/S- much shorter than most or all children of the same age and gender, puberty may come late or may not come at all Cx- may be unknown, poorly developed pituitary glands Rx- growth hormone injections given at home, side effects are headache fluid retention muscle and joint aches slipped bones at the hip 

Endocrine Disorders DWARFISM Hypofunction of pituitary in childhood Small size, but body proportions and intellect are normal Sexual immaturity Rx – early diagnosis, injection of growth hormone

Endocrine Disorders Addison’s Disease Cause- adrenal glands not working properly, decrease in androgens or corticosteroids s/s- Weight loss, muscle weakness ,fatigue that gets worse over time, low blood pressure, patchy or dark skin Rx- corticosteroid or androgen replacement

Endocrine Disorders Cushing’s Syndrome Cx- body tissues exposed over time to too much of the hormone cortisol (stress hormone), usually from a medication or tumor s/s-Upper body obesity, thin arms and legs, severe fatigue and muscle weakness, high blood pressure, high blood sugar, easy bruising Rx- wean medication or remove tumor

Endocrine Disorders Diabetes Mellitus Caused by  secretion of insulin Can be insulin dependent (juvenile/Type I) or non-insulin dependent (Type II) Symps – polyuria, polyphagia, polydipsia, weight loss, blurred vision, and possible diabetic coma Since glucose not available for cellular oxidation, body starts to burn up protein and fat If not treated, excess glucose in blood (hyperglycemia) and glucose secreted in urine (glycosuria)

Endocrine Disorders If too much insulin is given, blood sugar may go too low (hypoglycemia  insulin shock) If blood sugar gets too high – hyperglycemia  diabetic coma Type II (non-insulin dependent) is most common, usually familial, occurs later in life, control with oral hypoglycemic drugs and diet Tests for Diabetes – blood sample measured in glucometer – done by patient in home – normal blood sugar 80-100 mg http://www.youtube.com/watch?v=jHRfDTqPzj4

Endocrine Disorders Hyperthyroidism Overactive thyroid, thyroid releases too much of its hormones Cx- Graves Disease, too much iodine, thyroiditis, tumors, large amounts of thyroid hormone S/S- Difficulty concentrating, fatigue, Goiter, thyroid nodules, Heat intolerance, increased appetite, sweating, irregular periods, nervousness, weight loss Rx- Antithyroid medications, radioactive iodine (which destroys the thyroid gland and stops the excess production of hormones), or surgery to remove the thyroid

Endocrine Disorders Hypothyroidism underactive thyroid, usually in women over 50 Cx- medications, congenital, radiation, radioactive iodine, S/S- fatigue, sensitivity to cold, heavier periods, brittle hair and nails, paleness, depression, weight gain, decreased taste and smell Rx- medication to raise blood levels

Endocrine Disorders Tetany In hypoparathyroidism, decreased calcium levels affect function of nerves S/S- Convulsive twitching develops, person dies of spasms in the respiratory muscles Rx – Vitamin D, calcium and parathormone