BIO202H5 Lecture Notes - Lecture 5: Placodermi, Peristalsis, Parietal Cell
Document Summary
Suspended small particles are abundant in aquatic habitats. Many more aquatic animals are suspension feeders (feeding on debris, phytoplankton, zooplankton) Reynolds # = size x velocity x density/ viscosity. Small reynolds number = fluid flow influenced by inertial forces (flow is turbulent and boundary layer is thin) Structural relationship in jaws increase mechanical efficiency. Earliest jaws in placoderm fish were complex lever systems (skill raising and mandible lowering at the same time) Mechanical advantage: point of rotation: force applied to crush something from muscles as well as force that is causing resistance = contributors to point of rotation and provides mechanical advantage, ex: dunkleostus. Class 3 lever : force closest to fulcrum; both force and resistance on the same side of fulcrum: point of rotation, similar to forceps, limitations as to how far you can move the neck. Class 1 lever: force and resistance on opposite sides of fulcrum: similar to can opener, lower jaw remains stationary.
