PSL300H1 Lecture Notes - Lecture 2: Tryptophan, Immunocytochemistry, Blood Sugar
Document Summary
Why did it take so long before the first hormones were identified: not seen as important, brain control dominant/ at that time all homeostasis are thought to be controlled by the brain, bioassays not available, not true. There were bioassays at that time: chemical separation methods inaccurate, first huge challenge. Hormones have very low concentrations, it"s hard to separate them out. 1900 1910 face off - poland vs england. Neural control: pavlov and most physiologists (including mcleod here in toronto) Hormonal control: starling leader of splinter group. Bayliss & starling discover secretin 1902 initially dispute neural control of pancreatic secretions. Their theory: neural control did not have a role in pancreatic function. Reality: both hormonal (slow/sustained)and neural (fast/short term) controls required. Ernest starling, british physiologist first used the term hormone in 1905 derived from. Transported in the circulation to distant targets. Active on specific receptors on target cells. If receptor cannot stimulate the pathway problem.
