BIOL 320 1st Edition Lecture 2 Outline of Last Lecture I Review of Epithelial Tissue Cell Types A Description B Function C Location II Endocrine System A Definition of Endocrinology III Hormones A Definition B Categories C Mechanism of Action D Target Cell Specificity E Interaction of Hormones at Target Cells F Control of Hormone Release IV Hypothalamus and Pituitary A Structural and Functional Relationship Outline of Current Lecture V Posterior Pituitary Hypothalamic Hormones A Regulation B Oxytocin C Antidiuretic Hormone i Fun with ADH VI Hypothalamic Hormones A Release To B Target C Regulation D Description of Hormones VII Anterior Pituitary Hormones A Regulation B Description of Hormones VIII Thyroid Gland A Location and Structure B Thyroid Hormones C Homeostatic Imbalances IX Parathyroid Glands A Location and Structure B Parathyroid Hormone C Homeostatic Imbalances Current Lecture Posterior Pituitary Hypothalamic Hormones Regulation Neural ADH and Oxytocin are hypothalamic hormones not pituitary hormones posterior pituitary allows for release into bloodstream Oxytocin Paraventricular hypothalamic nuclei produce hormone Released during childbirth stimulant of uterine contractions and in nursing women Acts via the PIP2 Ca2 second messenger system Positive feedback loop Antidiuretic Hormone ADH or Vasopressin AVP Supraoptic hypothalamic nuclei produce hormone Released to inhibit or prevent urine formation Acts via the cAMP second messenger system Targets the kidney tubules to respond by reabsorbing more water from the forming urine and returning it to the bloodstream Fun with ADH o Diabetes insipidus Tasteless Overflow Excessive urination without sugar in the urine ADH is not released Blood pressure is decreased Dehydration can occur Can be result of trauma to the head that target the supraoptic hypothalamic nuclei o Breaking the Seal Once you have had to go to the bathroom the first time while drinking alcohol you continuously have to go Alcohol inhibits ADH hormonal system slow to self adjust correct o Hangover Result of dehydration due to decreased release of ADH Ventral Hypothalamic Hormones Released Into o Hypophyseal portal system Target o Anterior pituitary Adenohypophysis Regulation o Hormonal Description of Hormones o Growth Hormone Releasing Hormone GHRH Triggers the anterior pituitary to release growth hormone GH o Somatostatin or Growth Hormone Inhibiting Hormone GHIH Inhibits the anterior pituitary release of growth hormone GH o Thyrotropin Releasing Hormone TRH Triggers the anterior pituitary to release thyroid stimulating hormone TSH or Thyrotropin o Corticotropin Releasing Hormone CRH Triggers the anterior pituitary to release adrenocorticotropin hormone ACTH o Gonadotropin Releasing Hormone GnRH Triggers the anterior pituitary to release gonadotropins LH and FSH to reproductive structures ovaries or testes o Prolactin Releasing Hormone PRH Triggers the anterior pituitary to release prolactin for milk production o Prolactin Inhibiting Hormone PIH Inhibits the anterior pituitary to release prolactin Anterior Pituitary Hormones Regulation o Hormonal Description of Hormones o Growth Hormone GH Causes growth Highest levels during childhood Target EVERYTHING not just muscular skeletal Metabolic rate increases amino acid uptake increases to build protein and fat burning increases Glucose sparing other body system use other energy sources to preserve glucose for the brain energy requirement Increases sulfur uptake for cartilage growth Protein synthesis decreases with age muscle atrophy is a big problem unless activity is maintained Timing of sleep is critical for proper release Release is altered by stress Release changes in response to nutrient blood levels o Thyrotropin Thyroid Stimulating Hormone TSH Stimulates the thyroid to synthesize and release thyroid hormone TH o Adrenocorticotropic Hormone ACTH Stimulates the adrenal cortex to synthesize steroid hormones mineralocorticoids glucocorticoids and androgens o Follicle Stimulating Hormone FSH Stimulate the ovaries and testes to produce hormones estrogen progesterone by the ovaries and testosterone by the testes as well as other functions o Luteinizing Hormone LH Stimulate the ovaries and testes to produce hormones estrogen progesterone by the ovaries and testosterone by the testes as well as other functions o Prolactin PRL Stimulates milk production in mammary glands Release is tied to estrogen levels released when estrogen levels are high Thyroid Gland Location and Structure o Two lobed orgain joined by an isthmus o Sits on top of trachea o Well vascularized o Histology Follicular cells in direct contact with the follicle Produce thyroid hormone T3 active form and T4 inactive form mostly T4 Parafollicular cells not in direct contact with follicle Produces calcitonin Thyroid Hormones o Thyroxine T4 inactive form of TH two tyrosines and four iodines o Triiodothyronine T3 active form of TH two tyrosines and three iodines Tissues take up T4 and turn it into T3 Promotes normal Basal metabolic rate BMR Heart rate blood pressure Muscle function Nervous system development and function GI motility Female reproductive function Skin condition o Calcitonin Decreases concentration of calcium in blood Stimulates osteoblasts to reduces calcium levels and inhibit osteoclasts activity Higher in children than adults Not necessary for proper calcium homeostasis Homeostatic Imbalances o Myxedema Hypothyroidism Mucus swelling Symptoms Low BMR Constant chills Constipation Sluggish thinking Treatment Hormone supplement Iodine intake in diet Caused by Insufficient iodine intake in diet o Goiter can result Dysfunction with TRH or TSH release o Grave s Disease Hyperthyroidism Symptoms High BMR Constant sweating Anxious Exophthalmos bulging protruding eyeballs due to edema in eye socket Treatment Surgical removal of the thyroid gland Ingestion of radioactive iodine which selectively destroys the most active thyroid cells Caused by Autoimmune disorder where over secretion of TH results Parathyroid Glands Location and Structure o Positioned on the distal posterior side of the thyroid o Produce parathyroid hormone PTH o Composed of chief cells and oxyphil cells Parathyroid Hormone o Increases blood concentration of calcium o Stimulates osteoclasts activity o Inhibits osteoblasts activity o Causes GI tract to retain calcium do not waste o Causes kidneys to reabsorb calcium do not excrete Homeostatic Imbalances o Hyperparathyroidism Calcium