Nick Pytel Nate Mohney

 What are some of the structures associated with the endocrine system?  Pituitary Gland  Pineal Gland  Thyroid & Parathyroid Glands  Thymus  Adrenal Glands  Pancreas  Ovaries (females)  Testes (males)

 What is the major function of the endocrine system?  To maintain

 What are some of the processes regulated by the endocrine system?  Hydration (Post. Pituitary)  Metabolism (Thyroid)  Electrolyte Levels (Thyroid, Parathyroid, Adrenal)  Blood Sugar Levels (Pancreas, Adrenal)  Fight or Flight Response (Adrenal)  Reproduction (Ovary, Testis, Pituitary)  Growth (Pituitary, Thyroid)  …and many more

 How does the endocrine system regulate these processes?  Through chemical signals known as Human Insulin Human Testosterone Human Growth Hormone

 What is known as the “Master Gland?”  The pituitary gland  Why is it called this?  It is one of the most proximal endocrine glands to the brain  It’s hormones regulate those of other endocrine glands

 Remember that the anterior pituitary gland  is highly vascularized  contains many epithelial cells that secrete hormones  nerves from the hypothalamus stimulate the pituitary cells to release their hormones  Secretes several different hormones, but the two we will discuss are  Growth Hormone (GH) also known as somatropin  Adrenocorticotropic Hormone (ACTH) aka corticotropin

 Human Growth Hormone (aka somatotropin)  Indirectly stimulates the growth of muscle, bone, and other tissues  Acts on the liver, which releases somatomedins that directly affect:  Chondrocytes → Cartilage Formation → Bone Growth  Muscle Cells → Protein Synthesis → Muscle Growth  Fat Cells → Lipogenesis Triglyceride Structure

 Operates by

 ACTH stimulates the adrenal cortex to produce corticosteroid hormones including cortisol

 Cortisol is produced by the Suprarenal Glands in response to ACTH secretions  It is usually produced in response to stress  fasting, psychological (depression, fear, stress), prolonged exercise, hypoglycemia, and illness  It promotes gluconeogenesis  the production of glucose from lipids, glycogen, and proteins (which are broken down to fatty acids, glucose, and amino acids respectively)  Raise blood glucose levels to replenish depleted supplies  Prolonged secretion causes hyperglycemia

 The basis of cancer is when structural damage to the DNA sequence of a cell compromises the control of cell growth a division  Often requires damage to multiple genes that regulate cell division  The result is the cell proliferates uncontrollably  Causes include random DNA replication errors as well as damage to the DNA sequence (UV light, X- rays, chemical carcinogens)

 Benign Tumors  generally, uncontrolled cell proliferation begins in this way  are limited in growth by the presence of surrounding tissue  are made up of cells that are bound to one another and do not metastasize

 Pressure  A growing mass may put pressure on the surrounding organs: closing vessels and straining organs  Metastasis  The increased rate of division correlates to an increased rate in DNA replication errors, which may lead to loss of intercellular binding function  Lead to malignant tumors (cancer)  Adenomas  Particularly in tissue that secretes regulatory hormones, an increase in the number of cells would lead to an imbalance in hormone secretion.

 Adenoma – A benign epithelial neoplasm in which the tumor cells form glands or gland- like structures  Types of Pituitary Adenomas  Prolactinoma - Most Common - ~43%  Non-Secreting - ~30%  Growth Hormone Secreting - ~17%  ACTH Secreting - ~7%  TSH Secreting - ~3%  All Others… Rare

 Gigantism – Abnormal size or overgrowth of the entire body or any of its parts.  Abnormally large stature  Proportional  Before growth plates close in long bones 12 year old kid with his mother

 Acromegaly – Disorder resulting in progressive enlargement of face, hands, feet and soft tissues.  Occurs after growth plates have closed  Disproportionate growth Woman suffering from acromegaly at ages 16, 33, and 52. What changes do you notice?

 Severe Headaches  Arthritis and Carpal Tunnel Syndrome  Diabetes Mellitus  Renal Failure  Enlarged Heart and Hear Failure Shortened life span and diminished quality of life! What are some potential treatments?

Surgery – Transsphenoid Medication – GH Inhibitors with supplemental GH Radiation Possible side effects?

 Collection of symptoms derived from long term overexposure to cortisol  Cortisol is a key hormone in the body’s response to stress  Pituitary adenomas are most common cause – Cushing’s Disease  5x more common in women

 Increased central body fat – head, neck, torso  Moon face  Skin ulcerations  Buffalo hump  Immunosuppressed  Growth suppression (In children)  Mood changes (Depression)  Purple Straie

 24-Hour Urine Free Cortisol Level  Measure of how much cortisol is excreted via urine in a 24 hour period.  Normal range for adults… <100 micrograms/day  Positive test can be up to several times higher  What might interfere with the results?

If it is caused by a pituitary adenoma then the treatment is very similar to the treatment for acromegaly.  Surgical removal of tumor  Irradiation of tumor  Medications to inhibit tumor secretions or limit the effectiveness of the synthesis pathway

 Too little Growth Hormone leads to pituitary dwarfism  Too little ACTH leads to Addison’s disease

 Severely stunted growth  Proportional development  Treated with regular hGH injections  If treatment starts early the patient can achieve a near normal stature

 Symptoms  Fatigue  Weight Loss  Weakness  Dizziness  Hyperpigmentation  Treated with hormone replacement therapy. Fun Fact: Do you know someone famous who had Addison’s?