![]() The ninth vertebra is also known as sacral vertebra. 1.66D 1, D 2) and articulates with the pelvic girdle. The transverse processes are stout, fan-shaped (Fig. This vertebra is peculiar and has two-rounded condyles on the posterior side of the centrum for articulation with the anterior paired concavities of the urostyle. All the vertebrae excepting the first and the last one have typical structural construction. The anterior pair of processes are known as prezygapophyses and the posterior pair are called post-zygapophyses (singular-post-zygapophysis). The articulating processes are present on the neural arch. The lateral side of the neural arch carries transverse processes. The roof of the neural arch possesses a median elevation known as neural spine. On the dorsal side, the centrum bears a ring-like neural arch which encloses the neural canal. The centrum is greatly reduced.Ī typical vertebra has a solid cylindrical part known as centrum. Anteriorly it possesses two concave facets which fit with the paired occipital condyles of the skull. The transverse processes and the prezygapophyses are absent. It articulates with the occipital condyles of the skull. 1.66A) is composed of nine vertebrae and a terminal rod-like structure called urostyle (oura=tail and style=rod). Similar pair on the posterior side are known as posterior cornu which enclose the laryngotracheal chamber. The anterior pair are longer and extend up to the auditory capsules. There are two pairs of prolongations (or horns) from the body of hyoid apparatus. The body of the hyoid constitutes the main bulk of the apparatus. It also forms the supporting framework for the attachment of the tongue. The hyoid apparatus is essentially a cartilaginous structure which supports the floor of the buccal cavity (Fig. Both the upper and lower jaws are toothless in toad. The posterior part of the angulosplenial articulates with the upper jaw. Each half is developed from a Meckel’s cartilage and consists of three bones, the dentary, angulosplenial and mentomeckelian. The lower jaw is composed of two halves and the halves are united anteriorly by ligament (Fig. The palatine is rod-like and connects the maxilla with the sphenethmoid bone. The other two supporting bones are the pterygoid and the palatine. Behind the quadratojugal there is a very small Y-shaped supporting bone called the quadrate. A small hammer-like squamosal connects the posterior part of the upper jaw with the otic capsule.Įach half of the upper jaw is made up of small premaxilla, long slender maxilla and quadratojugal. The floor of the auditory capsule is supported by the lateral extension of the Para sphenoid and the dorsal side is covered by prootic bone. The auditory capsules are situated in front of the exoccipitals. The cartilaginous otic capsules are loosely attached with the cranium. ![]() The nose is covered dorsally by a triangular nasal bone and the floor is provided with the vomer (Fig. This bone is completely covered by frontoparietals on the dorsal side. A ring-like sphenethmoid bone is present at the anterior end of the cranium. The floor of the skull is formed of a dagger-like Para sphenoid (Fig.
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