PHGY 214 Lecture Notes - Oogenesis, Sertoli Cell, Fetus
Document Summary
Lecture 1 : chapter 5 general principles of endocrinology. Ductless glands, secrete hormones & travel through blood to all cells. Target cells have receptors, bind specific hormones. Regulate/direct particular functions: rates of enzymatic reactions, transport ions/molecules across cell membrane, gene expression & protein synthesis. Induce adaptive changes help body cope with stressful situations. Plasma concentration of hormone depends on: hormone"s rate of secretion by endocrine gland (major factor for all hormones, extent of binding to plasma proteins (for lipophilic, rate of metabolic inactivation & excretion (all hormones) Bind to surface membrane receptors, use second-messenger system. Most commonly due to abnormal plasma concentrations of a hormone (inappropriate secretion). Hyposecretion: too little secreted: primary abnormality within gland. Genetic, dietary, chemical, immunologic, cancer, etc: secondary normal gland but too little hormone secreted; deficiency of tropic hormone. Hypersecretion: too much secreted: causes: tumors; immunologic factors, primary abnormality within gland, secondary excessive stimulation from outside the gland.