One of two male whale sharks at the Georgia Aquarium. Turtles, water snakes, crocodiles, alligators, dolphins, whales and other water creatures will drown if they are kept in underwater too long. Previous page Circulatory system. Such is not the case, however, in the higher vertebrates that possess eggs with…. Reeder WG The digestive system.
Digestive System of Amphibians, Reptiles and Birds
But labial glands are open at the lips which do not play any role in digestion. Salivary glands which open into the buccal cavity are lingual, mandibular, maxillary, cricoary tenoid, palatinal and sphenopalatinal glands. The multi cellular salaivary glands are four pairs. They are Infra orbital, parotid, sublingual and sub-maxillary glands. Pharynx is marked off. On the roof of pharynx near the junction of two jaws a pair of openings is called Eustachian apertures.
Pharynx is not sharply demarcated from the buccal cavity. It receives the openings of esophagus and the glottis. Esophagus is a narrow tube and straight extends through the neck. Mucous glands are present. Oesophagus is a bng and narrow tube. It has thick walls. Mucous glands are absent. Oesophagus is a long thin walled tube. It is clearly marked off from the pharynx as well as stomach. The oesophagus is dilated into a thin-walled sac the crop. It secrete pigeon milk in both sexes and used to feed the young birds.
The wall of oesophagus is produced into the cardiac stomach to form cardiac valve. Stomach is a sac- like structure. Its anterior part is cardiac stomach and posterior part is pyloric stomach. At the end of pyloric stomach a small constriction is present. It possesses a pyloric sphincter. Stomach is divided into a glandular proventriculus and posterior muscular gizzard. Gizzard acts like grinding apparatus.
Stomach is divisible into cardiac, fundic and pyloric parts. Pyloric stomach contains pyloric valve. Intestine is differentiated into duodenum and ileum. Intestine very long and very much coiled because is a herbivorous animal Same structures are present. But the bile duct and pancreatic ducts open separately into the proximal and distal ends of the duodenum respectively.
A single rectal caecum is present. An ilio-colic valve is present at the junction of the small intestine and large intestine or colon. At the junction of these portions, a spiral shaped vermi form appendix is present. At the regular intervals of the colon shows pocket-like pouches - 'Haustra'. Colon shows longitudinal muscle folds taeniae'. Cellulose enzyme is produced. Cloaca is common opening for digestive'and urinogenital ducts.
It is divided into coprodaeum,urodaeum, and proctodaeum. Cloaca is large and divided into the same parts. On the dorsal side of the proctodaeum a thick walled blindsa"Bursa fabricii" is present. It becomes degenerated in the adult and is known as cloacal thymus. Liver is bilobed gland. The right lobe has a gall bladder.
Liver is bilobed dark red gland. Gall Bladder is absent. Separate bile ducts are formed. Liver is very large and consists of five lobes. Kupffer's cells are present in the liver. Gall Bladder is present. Pancreas is a whitish gland present between stomach duodenum. Pancreas is a pink coloured gland present the loop of duodenum. This category of animals is the most highly evolved and most complex.
They have bilateral symmetry and an internal skeleton of cartilage or bone. A nervous system at the back divides into the spinal cord and the brain, and most possess two pairs of limbs.
In human beings, the limbs are the legs and the arms, while in birds, they are the legs and the wings. All the animals ingest food through the mouth, are either cold blooded or warm blooded, take in oxygen and eliminate carbon IV oxide through gills or lungs and reproduce sexually.
These groups of animals are either aquatic and live in water, or are terrestrial and live on land. Fish are fully aquatic and cannot survive outside water. Amphibians live on land but reproduce in water. Reptiles, birds and mammals can be aquatic or terrestrial.
In terms of evolutionary origin, fish evolved first, followed by amphibians, reptiles, birds and then mammals. The most advanced of these groups of animals are the mammals. Human beings, the most advanced organisms in the animal kingdom, are mammals. Quick Answer Birds, reptiles, amphibians, mammals and fish all have a notochord, a post anal tail, pharyngeal slits and a dorsal nerve cord at some point of development. What Animals Live in the Temperate Forests?