ANP 1105 Lecture Notes - Lecture 5: Cyclic Adenosine Monophosphate, Codocyte, Endocrine System

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1105
• Professor: Joanne Savory

Document Summary

Affinity of hormone for receptor: different types of hormones (structural groups of hormones) Mechanism of hormone action: hormones alter levels of cell activity. Production of 2nd messenger (ex: cyclic amp (camp), calcium) Activation of protein kinases to regulate activity of key enzymes: steroid hormones. Entr y into the nucleus and activation of gene transcription. Blood level of hormone depends on: rate of synthesis, rate of degradation/clearance from blood. Half-life: persistence of a hormone in the blood; usually <1 min to 30 min. Time to onset of hormone action variable: enzyme activation rapid (minutes); enzyme synthesis hours to days. Some hormones secreted as prohormones; activated once reach target cell. Duration of hormone action also variable (hours to days) Usually negative feedback (setpoint); sometimes positive feedback. 3 types of stimuli: humoral, neural and hormonal: humoral: hormone secretion in direct response to change in blood level of a nutrient, ion.