topic 1

• physiology is the study of how animals work
• physiological processes obey physical and chemical laws
• homeostasis- maintenance of internal consistency (ex: sweating, shivering, breathing)
• ectotherms do not regulate body temperature
• physiological phenotype is a product of genotype and environment (impacts gene expression)
• genotype- genetic makeup (genes)
• phenotype- morphology, physiology and behavior
• genotype is the product of evolution
• physical properties determine the structural difference
• electrical laws describe membrane function
• big animals have less surface area to volume ratio
• small animals have more surface area to volume ratio than large animals so they can lose heat more easily
• reducing surface area to volume ratio keeps animal warm
• regulation is a central theme in physiology
• conformers- internal conditions change with external conditions (ectotherms)
• regulators- constant internal conditions regardless of external conditions (endotherms)
• through feedback loops homeostasis is maintained; negative and positive feedback loops
• negative feedback loops- to resist the change of the environment, working against the change
• examples of negative feedback loops: regulating body temperature, blood pressure, hypoventilation, hyperventilation
• when CO2 increases, H2CO2, H+ and HCO3 increase as well
• when pH goes down, the concentration of H+ increases
• positive feedback loops are rare, not as common, and it's temporary.
• positive feedback loops examples: binding of oxygen to hemoglobin, oxytocin being released for uterine contraction for baby to be delivered, and clotting factors to stop bleeding
• equilibrium- no net change and no dissipation of energy
• steady state- no net change but continuous dissipation of energy or matter, what's going in is coming out
• phenotypic plasticity- single genotype generates more than one phenotype depending on environmental conditions