01:119:115 Lecture Notes - Lecture 45: Melanocyte-Stimulating Hormone, Signal Transduction, Melanosome

• School: Rutgers University
• Department: Biological Science
• Course: 01:119:115
• Professor: A Keating

Document Summary

Chapter 45 - hormones and the endocrine system. Intracellular receptors usually perform the entire task of transducing the signal within the target cell: the (cid:272)he(cid:373)i(cid:272)al sig(cid:374)al a(cid:272)ti(cid:448)ates the re(cid:272)eptor, (cid:449)hi(cid:272)h dire(cid:272)tl(cid:455) triggers the (cid:272)ell"s response. A variety of local regulators affect neighboring target cells. Local regulators called prostaglandins (pgs) are modified fatty acids derived from lipids in the plasma membrane: released by most types of cells into interstitial fluids, prostaglandins regulate nearby cells in various ways, depending on the tissue. Secretion is regulated by hypothalamic hormones: melanocyte-stimulating hormone (msh) regulates the activity of pigment-containing cells in the skin of some fishes, amphibians, and reptiles. Its major tropic action is to signal the liver to release insulin-like growth factors (igfs), which circulate in the blood and directly stimulate bone and cartilage growth. Concept 45. 4 nonpituitary hormones help regulate metabolism, homeostasis, development, and behavior.