SIMILARITIES AND DIFFERENCES IN DIGESTIVE SYSTEM OF MAMMAL (RABBIT) AND AMPHIBIAN (FROG)
|1. Omnivorous||1. Carnivorous|
|2. Alimentary canal consists of||2. Alimentary canal consists of i. Mouth|
|i. Mouth||ii. Buccal cavity|
|ii. Buccopharyngeal cavity||iii. Pharynx|
|iii. Pharynx||iv. Oesophagus|
|iv. Oesophagus||v. Stomach|
|v. Stomach||a. Cardiac part|
|a. Cardiac part||b. Fundic part absent|
|b. Fundic part||c. Pyloric part|
|c. Pyloric part||vi. Small intestine|
|vi. Small intestine: a. Duodenum b. Jejunum c. Ileum||a. Duodenum b. Absent c. Ileum vii. Large intestine or rectum|
|vii. Sacculus rotundus in rabbit||viii. Cloaca|
|viii. Caecum, Vermiform appendix||ix. Anus|
|3. Glands of alimentary canal are i. Salivary glands ii. Mucous glands iii. Gastric glands iv. Intestinal glands||3. Glands of the alimentary canal are the following: i. Mucous glands ii. Gastric glands iii. Intestinal glands|
|4. Accessory digestive glands i. Liver ii. Pancreas||4. Accessory digestive glands i. Liver ii. Pancreas|
|5. Mouth opens laterally and is surrounded by lips.||5. Mouth opens laterally. It opens and closes by the lowering and raising of the lower jaw as in all other higher vertebrates.|
|6. Teeth are in 2 sets i.e., milk teeth and permanent teeth. This type of teeth is called diphyodont. Teeth are with roots found in sockets and, therefore, are called thecodont. They are of different types, therefore, are called heterodont The dental formula||6. Teeth are present on upper jaw only. Teeth resemble those of Scoiiodon and are homodont, and pleurodont. Vomerine teeth present.
|7.• Mouth leads into the mouth-cavity - the space between mouth and pharynx. It is supported by jaws.
• Cheeks are situated at the sides while tongue is on the floor and palate forms roof.
• Tongue is very muscular and is provided with ridged and rough surface.
• It mixes with the saliva secreted by salivary glands. On the surface taste - buds are also found.
|7. • Mouth opens into the mouth1 cavity, which is continued into pharynx.
• Tongue is bifid, attached to the anterior part of the mouth cavity. Salivary glands are not found.
|8. Oesophagus is a slender straight tube, which leads on the pharynx to the stomach.It also secretes mucus, which helps in lubricating the food.||8. Oesophagus is not sharply distinguished from either mouth or the stomach. Mucous glands are found in oesophagus.
|9. Stomach is pear-shaped. Large, circular structure. It is distinguished into three parts - the cardiac part, the fundic part and the pyloric part.There are three types of gastric glands. a. Cardiac b. Fundic c. pyloric.||9. The stomach is a simple tube and consists of cardiac and pyloric. Gastric glands are present in stomach. Pyloric sphincter is also present, which separates stomach from intestine.|
|10. Length of the small intestine is greater and it is much coiled. The small intestine is provided with a large number of villi. There is also a ileo-coelic valve between the small intestine and the large intestine||10. Intestine is small. Its lining is not provided with either scroll valveorvilli. Duodenum is a U-shaped structure Small intestine is in a few coils.|
|11. There is also a caecum with scroll valve which is the first part of the large intestine. At the terminal end of the caecum is an appendix. Colon is followed by rectum.||11. Large intestine through rectum leads into the cloaca. There is a great distinction between large intestine and small intestine.|
|12. Liver is the largest digestive gland. In rabbit it is five-lobed. The bile-duct receives branches from each lobe.The bile from bileducts is poured into the duodenum.Glisson's capsule is present.||12. Liver is well-developed, made up of 3 lobes. Gallbladder is a rounded sac which stores bile. Common bile-duct is opens into the duodenum.|
|13. Pancreas is a diffused gland with small lobules. There are several pancreatic ducts, which open into the bile-duct.Pancreas is endocrine gland. In it are islets of langerhans. which produce insulin.||13. Pancreas is a cream-coloured, compact gland made up of small lobes situated between stomach and through the pancreas, called common bile-duct or hepatopan-creatic duct.|