BIOH 113 1st Edition Lecture 5Outline of Last Lecture I. Endocrine SystemII. Endocrine System FunctionIII. HormonesIV. Target CellsV. Hormone Blood ConcentrationsVI. Hormone and Target Cell InteractionsVII. Major Endocrine OrgansVIII. OxytocinIX. ADHOutline of Current Lecture I. Pituitary-Hypothalamic RelationshipsII. Adenophypophyseal HormonesIII. Thyroid GlandIV. Thyroid HormoneV. CalcitoninVI. Parathyroid GlandsVII. Parathyroid HormonesCurrent LectureI. Pituitary-Hypothalamic Relationshipsa. Anterior Lobe- is an outpocketing of the oral mucosai. There is no direct neural contact with the hypothalamusii. There is a vascular connection through the hypophyseal portal system consisting of:1. The primary capillary plexus2. The hypophyseal portal veins3. The secondary capillary plexusII. Adenophypophyseal HormonesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.a. The seven hormones of the adenohypophysis:i. Abbreviate as: GH, TSH, ACTH, FSH, LH, MSH, and PRL—will detail laterii. Tropic hormones regulate the activity of other endocrine glands1. The tropic hormones that are released are: a. TSH- thyroid stimulating hormoneb. ACTH- adrenocorticotropic hormonec. FSH-follicle stimulating hormoned. LH- luteinizing hormoneb. Growth Hormone (GH)i. Produced by somatropic cells of the anterior lobe that:1. Stimulate most cells, but target bone and skeletal muscle2. Promote protein synthesis and encourage the use of fats for fuelii. Metabolic Action:1. GH stimulates liver, skeletal muscle, bone, and cartilage to produce insulin-like growth factors (IGFs)2. Direct action promotes lipolysis and inhibits glucose uptake—this is the glucose sparing effectc. Prolactin (PRL)i. In females, PRL stimulates milk production by the breasts and may enhance testosterone production in malesii. Triggered by the hypothalamic prolactin-releasing hormone (PRH)iii. Inhibited by the prolactin-inhibiting hormone (PIH)iv. Blood levels rise toward the end of pregnancyv. Suckling from babies stimulates PRH release and encourages continued milk productiond. Thyroid Stimulating Hormone (TSH)i. Tropic hormone that stimulates the normal development of secretory activity of the thyroid glandii. Triggered by hypothalamic peptide thyrotropin-releasing hormone (TRH)iii. Rising blood levels of thyroid hormones act on the pituitary and hypothalamus to block the release of TSHe. Adrenocorticotropic Hormone (ACTH)i. Stimulates the adrenal cortex to release corticosteroidsii. Triggered by hypothalamic corticotropin-releasing hormone (CRH) iii. Internal and external factors such as fever, hypoglycemia, and stressors can trigger the release of CRHf. Gonadotropins- follicle-stimulating hormone (FSH) and luteinizing hormone (LH)i. Regulate the function of the ovaries and testesii. FSH stimulates gamete (egg/sperm) productioniii. Triggered by the hypothalamic gonadotropin-releasing hormone (GnRH) during and after pubertyIII. Thyroid Glanda. The largest endocrine gland, located in the anterior neck, consists of two lateral lobes connected by a median tissue mass call the isthmusb. Composed of follicles that produce the glycoprotein, thyroglobulinc. Colloid (thyroglobulin+iodine) fills the lumen, or space, of the follicles and is the precursor of thyroid hormoned. Other endocrine cells, the parafollicular cells, produce the hormone calcitoninIV. Thyroid Hormone (TH)a. Thyroid hormone- the body’s major metabolic hormoneb. Consists of two closely related iodine-containing compoundsi. T4—thyroxin; has two tyrosine molecules plus four bound iodine atomsii. T3—triiodothyronine; has two tyrosines with three bound iodine atomsiii. T3 and T4 bind to TG in order to be carried through plasmac. TH is concerned with:i. Glucose oxidationii. Increasing metabolic rateiii. Heat productiond. TH plays a role in:i. Maintaining blood pressureii. Regulating tissue growthiii. Developing skeletal and nervous systemsiv. Maturation and reproductive capabilitiesV. Calcitonina. Calcitonin- peptide hormone produced by the parafollicular cells—also called C cellsb. Decreases blood calcium levelsc. Is an antagonist to parathyroid hormonesd. Calcitonin targets the skeleton where it:i. Inhibits osteoclast activity (so bone resorption) and release of calcium from the bone matrixii. Stimulates calcium uptake and incorporation into the bone matrixe. Regulated by a humoral negative feedback mechanismVI. Parathyroid Glandsa. Small glands embedded in the posterior of the thyroidb. Cells are arranged in cords containing oxyphil and chief cellsc. Chief cells secrete parathyroid hormones (PTH)d. PTH regulates calcium balance in the bloodVII. Parathyroid Hormonesa. PTH release increases calcium in the blood and:i. Stimulates osteoclasts to digest bone matrixii. Enhances the reabsorption of calcium and the secretion of phosphate by the kidneysiii. Increases absorption of calcium by intestinal mucosal cellsb. Rising calcium levels in the blood inhibits the release of