BIOL 206 Lecture Notes - Lecture 14: Homeothermy, Poikilotherm, Ectotherm
Document Summary
Ex: drop leaf: negative feedback in the control of blood pressures. Pressure receptors in the walls of certain arteries detect and increase of bp. Blood pressure- hydrostatic pressure; the force of blood on walls of vessels. Brain receives and integrates input: brain signals heart and blood vessels. Heart rate slows and vessels dilate (increase in diameter) Example of negative feedback and homeostasis: pressure receptors= receptors. Brain signals heart and blood vessels- effector: called negative because it makes the opposite change, negative feedback never stops. Brain never stops: feedforward mechanism in digestion. Ex: event think about, smell, see food digestive system begins to get ready- because taking in whole chunks of organisms takes a lot of work. If can start eating before mechanism starts- can get ahead of game. When stomach growls- stomach contracting/ creating turbulence while preparing for food. Once digestive system starts, secretions simulated: chemoreceptors in nose and mouth send signals to the brain.
