BIOL373 Lecture Notes - Lecture 5: Endocrine Gland, Gene Expression, Unit
Document Summary
Ion transport across a membrane: gene expression -> protein synthesis. Exocrine: normal epithelial layer with a duct. Endocrine: no exit, only way to exit is via capillaries, doesn"t have ducts, extensive er, vesicles containing their hormone product near the plasma membrane. Classic approaches in experimental endocrinology: ablate, remove suspected gland, replace, gland or extract of gland, create situation of excess- too much of it. Isolate active substance -> characterize chemically: throught these approaches- classic hormones were identified major tool of endocrinologists, then and now: biological assays (bioassays)- introduce hormone and monitor the response. How do we determine whether something is an endocrine gland: first we have to remove the suspected gland and monitor the animal for abnormalities (anatomical, behavioral, etc. ) Experiment: arnold adolph berthold (1803- 1861: long known that removing testes from farm animals reduced masculine behaviour and phenotype, berthold wondered whether effects were due to neural connections with testes, experimental models: chickens ei.
