Report :Digestive System of Snakes

1. Veterinary Medicine Damanhur University Report :Digestive System of Snakes Prof. Dr. Ashraf A. El Sharaby Presented by : MowaffaqShalaby

2. Anatomy of snakes

3. Oral cavity

4. An extrasensory organ in the floor of a snake's mouth sharpens its sense of smell. Called Jacobson's organ, it consists of two hollow, highly sensitive sac like structures. The snake's acute odor perception allows it to track both prey and potential mates. Heat Location with Pit Organs undefined Pit vipers detect prey using a two-chambered "pit" organ located between the eye and the nostril on each side of the head. Warm-blooded animals give off thermal radiation even when motionless. The snake's brain identifies this heat by comparing the temperatures in the outer and inner chambers. Since the brain distinguishes between input from the right and left pit organs, the snake can tell where the heat source is in relation to itself. It can strike accurately, even in the dark, at prey a fraction of a degree warmer. • NB: Snakes that lose their tongues may not feed. ( why ?? ) Tounge

5. The arrangement and number of teeth is extremely species specific. Some species of snake have virtually no teeth while others have very highly developed teeth. The function of undifferentiated teeth is to draw food items into the mouth rather than to chew. Teeth continue to be replaced throughout life, including the fangs. • The mouth of a snake can open widely by the independent movement of the jaws to accommodate relatively large prey. The mucous salivary glands moisten the mouth, lubricate prey, help for digestion and excrete salt. Venom glands that produce toxins to kill prey are modified salivary glands. Teeth

7. The oesophagus is flexible to accommodate relatively large prey. The cranial oesophagus is thinly muscled. At the level of the heart, the oesophagus passes through the vascular ring formed by the left and right aortae. It longitudinal folds and is covered with a columnar ciliated epithelium. The oesophagus terminates as the cardiac sphincter. The thick-walled, spindle-shaped stomach is muscular and flexible. The small intestine is relatively uncoiled but has several short transverse loops tightly enveloped by dorsal mesentery. It empties into the colon that may store faeces. The large intestine is relatively wide and is separated from the cloaca by a distinct fold . • NB: A small caecum projects from the proximal colon Oesophagus, stomach and intestines

8. The liver is elongated and is divided into several separate lobes. A characteristic of snakes is that there is a relatively long distance between the caudal tip of the liver and the gall bladder. Snakes have a well-developed gall bladder adjacent to the duodenum and caudal to the liver. Multiple bile ducts pass from the gall bladder, through the pancreas, into the duodenum.In most species, the gall bladder, pancreas and spleen are closely associated. In some snakes the pancreas may be fused with the spleen forming the splenopancreas. Liver, pancreas and gall bladder

9. The cloaca is divided into three parts (cranial to caudal): coprodeum (cranial), urodeum ( medial )and proctodeum ( caudal ). The coprodeum collects faeces from the colon. The urodeum, which is the midsection of the cloaca, collects urinary waste and products of reproduction. The urogenital papilla is situated dorsally behind a small fold. The proctodeum is the reservoir for faecal and urinary waste before excretion. Cloaca

10. Found in the tail region are the large intestine (Li), cloaca (Cl)

11. Thank You