BIOL211 Lecture Notes - Lecture 9: Cleithrum, Interventricular Septum, Hyaline Cartilage
Document Summary
Living on land is quite different than living in water. Air is less viscous & less dense but tetrapods need to overcome gravity. Need a skeleton that supports the body. Gas exchange organ cannot collapse tetrapods can use tidal flow with a sac- like lung. More opportunity for body temperature regulation: support and locomotion, support & locomotion on land. Gravity impacts support and locomotion on land. Fish are essentially weightless in water not true for land animals. Skeleton must be able to support tetrapods. Differs from the skeleton seen in fishes: bones. Skeleton is made up of bone . External layer of bone is compact lamellar bone. Joints are covered by articular cartilage . Entire joint is enclosed in a joint capsule : axial skeleton. The axial skeleton adapted to life on land. Vertebrae processes known as zygapophyses provide additional support in the spine.