Its mucous epithelial lining contains some mucous glands.The pharynx leads into oesophagus through a wide opening named the gullet.In male frog, near the angle of two jaws, on the floor of the pharynx on either side, is present the small opening of a vocal sac.The eustachian aperture opens into the middle ear.On the roof on either lateral side, there is a wide eustachian aperture.The glottis leads to the laryngo-tracheal chamber.There is a longitudinal slit-like aperture present on the floor of the pharynx named glottis.Various apertures open into the pharynx.As the pharynx is short in size, sometimes both the buccal cavity and the pharynx are described as bucco-pharyngeal cavity.The buccal cavity leads into the pharynx.While swallowing the food, the frog depresses the eyes inwards and pushes the food inside the pharynx.Bulgings of orbits or eyeballs are present on the roof of the buccal cavity and behind the vomerine teeth.These openings are the part of frog’s respiration.These internal nostrils connect the nasal cavity and the buccal cavity.Just in front of the vomerine teeth, a pair of small openings present which are called internal nostrils or internal nares.Located on the roof of the buccal cavity.The protrusion of the tongue is brought about by the change of pressure in the large sublingual lymph sac.The posterior end of the tongue can be flicked out and retracted immediately after catching the prey with its slimy surface.fig: Preying mechanism of frog with tongue. ![]() Its anterior end is attached to the inner border of the lower jaw and the posterior end is free.It is large, muscular, sticky, and protrusible.The tongue is present on the floor of the mouth cavity.The teeth of frogs are replaced several times when they are lost and that’s why frogs are polyphyodont.The tooth contains a central pulp cavity open at the side and filled with a soft nourishing pulp. ![]() The tip of the crown is covered with enamel which is a very hard substance. The free part of a tooth is called the crown.Teeth are attached to the jaw by a broad base.Homodont means all the teeth are similar and acrodont means the teeth are not set in a socket. The teeth of the frogs are homodont and acrodont.The teeth are just for holding the prey and preventing the prey from slipping out. The frogs can not chew with their teeth.Two small bones are also present on the roof of the mouth called vomers and they bear vomerine teeth.Teeth are small, conical, and backwardly pointed.Teeth occur in a row and on either side of the premaxillae and maxillae bones.The premaxillae and maxillae bones of the upper jaw contain teeth.The buccal cavity has teeth, tongue, internal nostrils, and bulging of orbits.So no saliva secrets and no digestion occurs in the buccal cavity. There are no salivary glands present in frogs.The buccal cavity has mucous glands which secret mucous to lubricate the food.It has ciliated columnar epithelial lining.The mouth leads into the buccal cavity.Lips cover the jaws and the lips are immovable.įig: Bucco-Pharyngeal cavity of a frog.The upper jaw is fixed and the lower jaw can move up and down.The mouth extends from one side of the snout to another side of the snout.It is a wide transverse slit-like aperture.The mouth is the transverse and largest aperture of the body.The alimentary canal of frog starts from the mouth. ![]()
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