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ZOO: 4926 Oct. 13, 2011. Feeding II - Biomechanics. Lecture Outline Review of skull anatomy Suction feeding and jaw protrusion Feeding: a phylogenetic perspective Pharyngeal jaw anatomy. Where is the suspensorium?. Perciform skull. Label the premaxilla and its ascending process.
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ZOO: 4926 Oct. 13, 2011 Feeding II - Biomechanics
Lecture Outline • Review of skull anatomy • Suction feeding and jaw protrusion • Feeding: a phylogenetic perspective • Pharyngeal jaw anatomy
Where is the suspensorium? Perciform skull Label the premaxilla and its ascending process Where is the levatoroperculi? Name the three ways to open the mouth
Linkage systems for suction feeding • Cranial elevation – epaxial muscles • Opercular series – Levator operculi (LO) rotates operculum back to pull on interoperculo-mandibular ligament (IML) which depresses lower jaw • Hypaxial mm – Sternohyiodeus- Geniohyoideus linkage system
Timing of muscle activation creates unidirectional flow Which muscles are active when the mouth opens? Closes?
jaw protrusion • Ventral portion of PM attached to lower jaw (depression) • Epaxial muscles elevate head • Rotation of the maxilla as cam
Branchial apparatus/basket: anterior is buccal cavityposterior is pectoral girdlesuspended from the skull by a thin bone (PB#1)
Lecture Summary • Skull anatomy: mechanical units • Suction feeding: timing of muscle activation, shape of buccal cavity • Feeding phylogeny: trend of increasing jaw mobility and mechanical degrees of freedom • Pharyngeal jaws: Upper = PB #3&4 • Lower = CB #5