BIOL 11100 Lecture Notes - Lecture 24: Endocrine System, Homeostasis, Comparator

• School: Purdue University
• Department: Biological Sciences
• Course: BIOL 11100
• Professor: Humphrey

Document Summary

Homeostasis: organisms must keep internal body conditions within optimal ranges (set points, homeostasis, keeping internal body conditions constant, organisms have set points for, body temp, blood glucose concentration, ion concentration. Hormones: hormones, signaling molecules released into circulation for organism wide signaling, endocrine signaling, hormones effective at low concentrations, affect growth, metabolism, development, and homeostasis, organs and tissues that secrete hormones are referred to as the endocrine system. 3 classes of hormones: peptides hormones, proteins, insulin, amino acid derivatives, modified amino acids, melatonin, steroid hormones, derived from cholesterol, testosterone and estrogen. Classification of hormones: hormones may be classified as, hydrophobic (nonpolar) - fat soluble (lipophilic) Bind to intracellular receptors: hydrophilic (polar) - water soluble, non-steroid hormones. Glucose regulation by the pancreas: meal is skipped or you are exercising, glucose levels decrease, pancreas secretes glucagon, cells break down glycogen, release glucose into bloodstream, levels increase (negative feedback to the pancreas, pancreas stops secreting glucagon.