Chapter 8 Flashcards
Vertebral column of fishes
Intervertebral articulations permit only side to side movement
Tetrapods vertebral column
Dorsoventral flexibility
Some side to side limitation
Modern vertebrae is made up of what
Centrum, neural arch, health arch, apophyses
Transverse processes
Diapophyses, articulate with ribs, some muscles attached, extend or flex vertebral column
Pre and post zygapophyses
Interlock and limit dorsoventral flexion
Side to side flexion
Parapophyses
Lateral from centra, few tetrapods, articulate with capitulum of bicipital rib
Hypapohyses
Mideventral, snakes
Morphogenesis of vert
Sclerotome mesenchyme from mesoderm somites-> surround notochord and neural tube-> vertebral blastema-> chondroblasts-> cartilagenous centrum and arches-> later replaced by bone
Diplospondyly
2 centra per segment in fishes and primitive tetraposs
Vertebral column of fish
Diverse
Dorsal trunk, caudal tail
Fibroelastic ligament overlies and connects neural spine in all fish
Vert column sharks
Notochord throughout vert columnamd restricted within centra, centra restricted at each end, vertebral canal has paired dorsal plates, dorsal intercalary plates, hemal arches, ventral intercalary plates
Teleosts vert column
Well Ossified
Remnant of notochord
Connected by complex of collagenous and elastic ligaments
Neural spines tall
Rachitomous vert
Early tetrapods
Several bones per segment
Hypocentrum- u shaped and cradled notochord
Pluerocentra pair
Neural arch
Rachitomous-> modern amniotes
Increased pleurocentra and reduced hypocentra
Amphicelous vert
Concavity at both ends