BIOLOGY 225 Lecture Notes - Lecture 24: Cerebral Circulation, Thyroid, Bradykinin Receptor B2
Document Summary
Isoreceptor - structurally and functionally distinct receptors for the same ligand. Isoreceptors often have differential tissue distributions, different second messengers and physiological actions. Inc cerebral blood flow and cerebral glucose utilization. Very common in europe in medieval times. Thyroid hormone necessary for brain development - neuron differentiation. W/o hormone, can"t differentiate mental retardation. Structure of thyroid hormones / thyroid hormone synthesis. Two primary forms of thyroid hormone: t3 and t4. Only one place in body absorbs iodine - thyroid. Can see if hyperactive, hypoactive, or normal. Tyrosine monoiodo/diiodotyrosine t3 or t3 + dit t4. T3 and t4 are the functional hormones, and t4 is the one that is usually released from the thyroid. Hypothalamus - thyrotropin (tsh) releasing hormone (trh): pituitary tsh release is stimulated by trh, pituitary tsh release is inhibited by t3/t4, thyroid gland, deficient (or large excess) iodide-inhibition. If no iodine, neg feedback doesn"t work bc thyroid only producing defective thyroid hormone, keeps going goiter.
