c.i.4.a. When blood volume is low c.i.4.b. When blood pressure is low c.i.4.c. Blood osmolarity c.i.4.c.i. Concentration of solute needs to be high, low water c.i.4.c.ii. Low solute, high water c.i.4.c.iii. High blood osmolarity and low blood volume and pressure, ADH is sent out. c.i.4.d. Needs an action potential so that it exocytosis the ADH
c.i.5. Effects of ADH c.i.5.a. Water reabsorption c.i.6. Inhibitors c.i.6.a. Alcohol prevents the firing of action potential from the hypothalamic nerves c.i.6.b. You have to pee a lot when your drunk because there is less ADH in the system c.ii. Paraventricular (oxytocin) c.ii.1. We have paraventricular nucleus in the hypothalamus c.ii.2. Oxytocin c.ii.2.a. Responsible for stimulating smooth muscle contraction in the uterus c.ii.2.b. Comes from supraoptic nerves c.ii.2.c. Inducer c.ii.2.c.i. Infant nursing (infant is sucking on the nipple) c.ii.2.c.ii. Infant crying c.ii.2.c.ii.1. Doesn’t have to be your baby c.ii.2.c.ii.2. Can stimulate oxytocin to be release c.ii.2.d. Oxytocin c.ii.2.d.i. Causes milk to be moved out of the secretory portion and into the duct portion (milk letdown) c.ii.2.e. Effects c.ii.2.e.i. Uterine contractions c.ii.2.e.ii. Milk letdown c.ii.2.f. Differences of prolactin and oxytocin c.ii.2.f.i. Prolactin doesn’t cause milk letdown, it causes milk production. Milk letdown is oxytocin c.ii.2.g. Inhibitors
c.ii.2.g.i. Catecholamines c.ii.2.g.i.1. A stressed mother cannot be releasing a lot of milk 7. Thyroid Gland a. Gland is really made up 3D spheres, that are lined by a single layer of cells called follicular cells b. Thyroid Follicle b.i. Thyroid globulin b.i.1. Glycoprotein b.i.2. Precursor to T3 and T4 b.ii. Induced by TSH which is induced by TRH b.iii. Parafollicular cells b.iii.1. Don’t make up the lining of the follicle b.iii.2. Secretes calcitonin b.iii.3. AKA see saw cells b.iii.4. Capillary that is releasing TSH which is binding to receptors on the basal side of the cell and stimulating the cell, TSH also binds to and activates iodide pumps (sodium iodine transporters, symporters). The protein is up regulated by TSH. Iodide then comes into the blood cell, then an enzyme called thyroid peroxidase. The enzyme will oxidize iodide into iodine and then put iodine onto thyroidglobulin (concept is called iodinating). The transport of iodide into the apical surface of the cell is called pendrin transporter. Thyroglobulin becomes iodinated so now we can endocytosis and lysosomes will cut up so the thyroglobulin so that T3 and T4 will be released. T3 and T4 binds to TBG, transthyretin or albumin. b.iv. Goiter b.iv.1. Too much thyroid in neck c. Homeostasis of Thyroid Gland c.i. Decreased levels in T3 and T4, less negative feedback c.ii. Hypothalamus releases TRH
c.iii. TRH goes to the anterior lobe and TSH is released c.iv. TSH goes to the thyroid gland and then releases T3 and T4 c.v. Increased levels of T3 and T4 c.vi. If you had a tumor in your pituitary you’re making too much TSH c.vi.1. Overstimulate the thyroid gland c.vi.2. TRH levels are low c.vi.3.