The spiral-shaped cochlea is part of the inner ear; it transforms sound into nerve impulses that travel to the brain. The fluid-filled semicircular canals (labyrinth) attach to the cochlea nerves in the inner ear. They send information on balance and head position to the brain. The eustachian (auditory) tube drains fluid from the middle ear into the throat (pharynx) behind
The alimentary tract of starts from mouth, there they have beak for breaking the prey’s shell and it is broken down to small pieces in that buccal mass consisting of mouth, pharynx, radula and salivary glands. Salivary glands secrete digestive enzymes while another pair secretes a toxin which paralyses the prey making it easy. Then food passes through oesophagus which has more digestive glands and transferred to crop which is a temporary storage of partly digested food before it enters the stomach. Stomach is a very muscular organ here the food is churned up into a slush in the stomach and it enters the caecum. In the caecum, where most of the absorption happens, food is sorted into fluids and particles.
Through the way of scissors a cut is made from the base of the operculum to the eye, as close as possible. The operculum can be removed and the gills are exposed. Most fishes have four gills on the lateral sides near the head. Any mucus, present on the gills, have to be removed to get a clear view of the arches. The gills are layered and a probe is used to separate the gill arches.
Introduction Gallbladder is an organ in the body and it is part of the biliary system. It is a pear-shaped muscular sac that is located on the ventral surface of the liver and on the right side of the abdomen. Moreover, it has 3 layers; an outer serous peritoneal layer, a middle smooth muscle layer and the last layer is an inner mucosal layer which is connected to the lining of the bile duct. The main function of the gallbladder is to store and concentrate bile which helps the body to break down and digest fats. The liver produces bile which flows into the gallbladder through the bile ducts.
The operculum is corneous (Alderson 2015). Four main structures of Pomacea urceus can be observed: the foot, visceral mass, mantle and the face. The foot is the soft muscular part that is used to move about. Its visceral mass houses the digestive apparatus and the pericardial cavity. The mantle has the function of secreting the shell and the face consist of two long tentacles, with the eyes being at its base.
It also marks the zone along which the Tethys Ocean was consumed by subduction processes. The ITSZ can be traced for more than 2000km (Windley, 1986) between these regions and host a variety of rock types that tell us quite a bit about the orogen. Complete successions of ophiolites occur, some containing diamonds as well, suggesting high pressures during subduction and rapid extrusion along the suture zone. Glaucophane schists also occur in narrow belts along the ITSZ in Pakistan (Windley, 1986). Olistoliths occur in northwestern India and consist of reef and and continental slope sediments in abyssal tubidite deposits.
SALIVARY GLANDS Although classed as accessory organs to the alimentary canal. Saliva plays a vital part in chemical digestion of ingested food in the mouth. The mouth is lined with a mucous stratified epithelial membrane, reflecting the wear and tear associated with this area. There are three different types of gland situated within the mouth. The parotid glands are the largest saltatory glands, but are responsible for only 25% of daily secretions.
The pharynx is a muscular tube that extends supero-inferiorly from the base of the cranium to the level of the inferior surface of the body of the sixth cervical vertebra. The pharynx lies dorsal to the nasal cavity, the oral cavity and the larynx. The nasal portion of the nasopharynx has bony elements in its wall and thus it is rigid, whereas the pharyngeal portion is contractile as a result of the muscular nature of its wall.4 The relationship between craniofacial morphology and respiratory function has been studied extensively since the beginning of 20th century54. Some authors claim that patients with deficient respiratory functions present with lip incompetency, increased anterior face height, maxillary constriction, protruded maxillary
There are two small openings, anterior and posterior canaliculi for the chorda tympani nerve and petrotympanic fissure in the upper part of this ring. Chorda tympani enters in tympanic cavity through posterior canaliculi and exits through anterior canaliculi which opens at the medial end of petrotympanic fissure (4). Very few studies have described the variations in the origin and course of chorda tympani. A study conducted on 200 specimens of human temporal bones revealed the variant origin of chorda tympani. It was located in the proximal third (in 20 % cases), middle third (in 70% cases) and in distal third (10% cases) of mastoid segment of facial nerve (1).