MCDB 418 Lecture Notes - Lecture 3: Phosphorylation, Oncotic Pressure, Blood Vessel
Document Summary
Lecture 3: the hypothalamus and pituitary axis ii. Neurons that originate in hypothalamus terminate in posterior pituitary. Neurohormones oxytocin & vasopressin synthesized in cell body + travel in vesicles down axons. Sources: synthesized at son and pvn cell bodies transported to pars nervosa (storage site) Secrete upon stimulation into inferior hypophysial artery target tissues. Structure: ot and avp consist of 9 amino acids (short) folded into a ring through a disulfide bond at a1 and a6. Avp differs from ot at a3 + a8. Binding proteins: ot + avp are associated with larger proteins called neurophysin which act as transport/carrier proteins. Different isoforms/names of ot and avp found in different animals. Discovered in 1909 by sir henry h. dale. Vincent du vigneaud defined structure of ot + identified 9 amino acids. Suckling, visual, psychological stimuli sensory or visual afferent nerve fibers spinal cord. Hypothalamus: magnoneurosecretory cells posterior pituitary (exocytosis) oxytocin. Oxytocin smooth muscles surrounding gland ducts: contraction milk ejection.