ST120 Concorde Career College, Portland Define the term endocrine. Describe the functions of the endocrine system. List and identify the structures of the endocrine system and describe the function of each. List the endocrine hormones, the source of each, and the effect each has on the body. Describe the effect of the hypothalamus on the endocrine system. Describe the mechanism by which the endocrine system helps to maintain homeostasis. Describe common diseases, disorders, and conditions of the endocrine system including signs and symptoms, diagnosis, and available treatment options. Demonstrate knowledge of medical terminology related to the endocrine system verbally and in the written form. Exocrine - ducts Lacrimal glands Salivary glands Sweat glands Sebaceous glands Pancreas Endocrine secretes directly into bloodstream The term endocrine refers to a gland that secrets directly into the bloodstream. The term exocrine refers to a gland that secrets directly onto a surface or through a duct. The endocrine system produces hormones as directed by the nervous system. Hormones are messengers, delivered via the bloodstream, that have certain effects of various cells, functions, or organs. Amino acid compounds Steroids Hormone secretion is regulated by a negative feed back system Pineal Pituitary Anterior lobe Posterior lobe (AKA - Pineal Body) Small, flattened, cone-shaped structure located posterior to the midbrain and connected to the roof of the 3rd ventricle. Produced by the pineal gland Melatonin is primarily produced at night (during darkness) Melatonin influences the sleep/wake cycle and seems to delay the onset of puberty Small gland approximately the size of an olive or a cherry located in the sella turcica of the sphenoid bone Attached to the hypothalamus by the infundibulum (stalk-like structure) Divided into anterior and posterior lobes Considered to be the “Master Gland” because it’s hormones regulate other glands. AKA - Hypophysis -tropin - Suffix that indicates hormones that stimulate other glands. 1. Growth Hormone (GH) 2. Thyroid Stimulating Hormone (TSH) 3. Adrenocorticotropic Hormone (ACTH) 4. Prolactin (PRL) 5. Follicle Stimulating Hormone (FSH) 6. Luteinizing Hormone (LH) General Information Messages (“releasing hormones”) from the hypothalamus are received in the anterior pituitary gland via a portal system Produced in the anterior pituitary AKA - Somatotropin Acts on most body tissues (primarily bone and soft tissues) Produced throughout the lifespan Produced in the anterior pituitary AKA - thyrotropin Stimulates the thyroid gland to produce thyroid hormones Produced in the anterior pituitary Stimulates the adrenal cortex Produced in the anterior pituitary Stimulates milk production (lactation) Produced in the anterior pituitary Classified as a gonadotropin Female - Stimulates ova development in the ovaries Male - Stimulates sperm cells in the testes Produced in the anterior pituitary Female - Causes ovulation and sex hormone secretion Male - Hormone is referred to as interstitial cell stimulating hormone (ICSH) and causes sex hormone secretion 1. Antidiuretic Hormone (ADH) 2. Oxytocin General Information Posterior pituitary hormones are produced in the hypothalamus and stored in the posterior pituitary Hormone release is controlled by nerve impulses that travel through a special pathway (tract) between the hypothalamus and the posterior pituitary Relationship of Hypothalamus and Pituitary Gland Posterior pituitary hormone Promotes reabsorption of water from the kidneys thereby decreasing the amount of urine excreted Posterior pituitary hormone Causes uterine contraction and milk let down (ejection) from the breasts Gigantism - Overproduction of GH during childhood. Acromegaly - Overproduction of GH during adulthood. Large stature Usually very weak Widening of the bones of the hands, feet, and face Largest endocrine gland Located in the neck Two main lobes (right and left lateral) Connected by a narrow band called the isthmus A third lobe, of conical shape, called the pyramidal lobe, frequently arises from the upper part of the isthmus, or from the adjacent portion of either lobe Thyroxine (T4) Principal thyroid hormone Increases metabolism; required for normal growth and mental capacity Triiodothyronine (T3) Secondary thyroid hormone Increases metabolism; required for normal growth and mental capacity Calcitonin Decreases calcium level in the blood Thyroid produces T4 and T3 in response to a signal (TSH) from the pituitary gland Overgrowth of the thyroid gland Smooth appearance May or may not cause overproduction of hormones Due to lack of iodine in the diet AKA neonatal hypothyroidism Failure of fetal thyroid to form Results in lack of physical growth and mental development Thyroid test required at birth to detect Lifetime treatment with thyroid supplement Atrophy of the thyroid in an adult Skin becomes dry and a peculiar swelling occurs Patient becomes mentally and physically sluggish Easily treated with hormone replacement therapy Most cases due to Grave’s disease Exophthalmos Thyroid storm Treat either with Chemical suppression Destruction of thyroid tissue (radioactive iodine) Surgical removal Routine blood test Specialty blood test (radioactive iodine uptake) Radionuclide scan (thyroid scan) Four tiny glands located posterior to the thyroid gland Embedded in the thyroid capsule Responsible for production of parathyroid hormone (PTH) One of three substances that regulate calcium metabolism PTH ▪ Promotes release of calcium from bone ▪ Causes kidney to retain calcium Calcitonin ▪ Lowers amount of calcium in circulation by allowing deposit in bone Hydroxycholecalciferol ▪ Active hormonal form of vitamin D ▪ Produced in the liver and kidneys ▪ Increases absorption of calcium from the small intestine to raise blood calcium levels All three substances work together to regulate calcium levels in the blood, maintain bone, and other functions (e.g., strong teeth) Positive Trousseau’s sign may indicate hypocalcemia due to hypoparathyroidism Positive Chvostek’s sign may indicate hypocalcemia due to hypoparathyroidism Caused by inadequate PTH production, damage to, or removal of the parathyroid glands Excess PTH causes removal of calcium from the bone causing weakening/kidney stones Two small glands Located above each kidney Outer portion - cortex Inner portion medulla Cortex Medulla Three main groups of hormones Glucocorticoids Mineralocorticoids Sex hormones (gonadocorticoids) Main hormone (95%) - cortisol (aka hydrocortisone) Maintains carbohydrate reserve by promoting conservation of glucose instead of protein Glucocorticoid production increases during times of stress Suppress inflammatory response Main hormone (95%) - Aldosterone Regulation of electrolyte balance Control reabsorption of sodium and secretion of potassium by the kidneys Influences development of secondary sex characteristics Male - hair growth on body, deepening of voice, maturation of sperm cells Female - breast development, changes in shape of pelvis (Hypofunction of Adrenal Cortex) Muscle atrophy Weakness Unusual skin pigmentation Electrolyte imbalance (Hypersecretion of Cortisol) Obesity with round face Bruises easily Muscle weakness Bone loss Elevated blood sugar Before and after treatment Released in response to sympathetic stimulation Fight or flight hormones Increase blood pressure Convert stored glycogen to glucose Increase heart rate Increase metabolism Dilate bronchioles Epinephrine (aka Adrenaline) and Norepinephrine Increase blood pressure and heart rate Activate cells influenced by sympathetic nervous system and others Both an endocrine and exocrine gland Located within the abdomen Produces two primary hormones Insulin Glucagon •Alpha cells producing glucagon (15–20% of total islet cells) •Beta cells producing insulin and amylin (65–80%) •Delta cells producing somatostatin (3–10%) •PP cells producing pancreatic polypeptide (3–5%) •Epsilon cells producing ghrelin (<1%) Produced in the beta cells of the islets of Langerhans Responsible for transport of glucose across plasma membranes where it is metabolized for energy Insulin increases the rate that the liver changes glucose into fat Lowers blood sugar level Increases rate that amino acids are converted into proteins Produced in the alpha cells of the islets of Langerhans Works with insulin to regulate blood sugar levels Causes the liver to release stored glucose into the bloodstream Increases the rate at which glucose is made from proteins in the liver Failure of the islet cells to produce an adequate supply of insulin Two types Type I Type II May be controlled with diet, exercise, insulin replacement therapy Male Testes ▪ Testosterone Female Ovaries ▪ Estrogens ▪ Progesterone Stimulates growth of primary sex organs (testes, penis) Supports development of secondary sex characteristics Stimulates growth of primary sex organs (uterus, tubes) Supports development of secondary sex characteristics Stimulates development of secretory portions of mammary glands Prepares uterine lining for implantation of fertilized ovum Aids in maintaining pregnancy Mass of lymphoid tissue in the mediastinum above the heart Produces Thymosin Assists in maturation of T lymphocytes after they leave the thymus and reside in the lymph nodes throughout the body Stomach secretes a hormone that simulates digestive activity Kidneys secret erythropoietin which stimulates red blood cell production in the bone marrow when a decrease in oxygen is detected Atria of the heart produce a substance called atrial natriuretic peptide (ANP) in response to increases filling of the atria. ANP increases loss of sodium by the kidneys and lowers blood pressure Placenta produces several hormones during pregnancy including HCG (measured during a pregnancy test) Produced by most body tissues Act near site of production Blood vessel constriction and dilation Bronchial constriction and dilation Intestinal constriction and relaxation (increased and decreased peristalsis) Many additional functions that are not fully understood