Amphibian (Frog) Internal systems

Digestive system Omnivore - Frogs eat bugs and some plant material. They swallow the food mostly whole and alive. The tongue, vomerine teeth and the maxillary teeth catch food. Mouth (no real break down happens here) Throat / Pharynx swallows the food Esophagus - food pipe where food goes into the internal digestive system

Digestion Continued Liver – has three lobes and help to break down fats and proteins Gal bladder – helps with fats Pancreas – helps to break down starches, carbohydrates and sugars involved in diabetes Stomach – has many enzymes that break food down further into useable parts for the cells

Small intestine – takes the broken down parts of food and gets them to the cells that need it by absorption Large intestine – un-used food/waste is packaged and gets ready to leave the body. Cloaca – large sac that holds solid and liquid wastes and reproductive gametes Anus – the way the material leaves the body.

Urinary System Liquid waste is removed from the body (excretory system) and blood is cleaned The kidney cleans the blood of all liquid toxins and then takes all un-used liquid waste and toxins then removes it from the body by way of the uriters to the bladder, then to the cloaca and out the anus. usually gametes travel with urine from the cloaca. The kidneys are protected by fat and by the reproductive gland. Located by the backbone on the dorsal surface.

Respiratory system The mouth and nostrils take the air into the mouth and the air can go one of two places, either the air sac for sounds or the throat/ pharynx. Once in the pharynx air goes to the windpipe trachea and then to the lungs. (bags of cells)

Respiratory system Small cells in the lungs fill with oxygen and then push the oxygen into the blood. (closed system) The blood then flows to all parts of the body by way of vessels. Arteries carry blood; rich in oxygen and veins carry blood; poor in oxygen back to the lungs to get more oxygen.

Respiratory system The skin is also used as a secondary respiratory system. Oxygen comes across the moist skin (mucus glands keep it moist) and then that oxygen goes directly to the cells for “quick” energy for the cells.

Circulatory system This system has all veins and arteries to move the blood, so it is called a closed system. Adult amphibians have a heart that has three chambers and pumps blood. Heart – 2 atriums and 1 ventricle It pumps the blood through-out the body at a steady beat. Squeeze and release.

Circulatory system Arteries – take blood from the heart that has gotten oxygen from the lungs and then gets it to the cells and organs in the body. Veins – take the blood from the organs once they have used the blood and returns it to the heart to get more oxygen. (closed system, no blood is lost or absorbed)

Circulatory system Kidney – cleans the blood of major toxins Liver – cleans the blood of toxins Spleen – organ that makes more blood as needed for the body. (regulates) Blood cells cannot last a lifetime they get worn out and new ones are needed to replace them

Skeletal system Endoskeleton made of hard bones that protect the internal organs. Gives shape to the frog. Head – Skull protects the brain Ribs and Back bone – Protect the heart, liver and spleen Appendages and the flanges – hind, fore legs and the toes and give support and help with movement

Nervous system Complex system. The frog has all five senses. He/ she can smell with its nostrils and that information goes directly to the brain (olfactory nerve) He / she can taste and the tongue and mouth take that information directly to the brain to several different nerves in the cortex.

They can hear and the sound waves go to the tympanic membrane and then to the estuation tube then to the auditory nerve in the brain They can feel – they have nerves in every part of their body to respond and feel their surroundings They can see light and colors these go to the visual part of the brain and then is processed in the cerebellum of the brain.

All the nerves travel through the body by way of an organization tube called a nerve cord. They then branch off into groups at different points where a ganglion then transfers the information to the cells themselves. Information moves to and from the body by the ganglion and nerve cord. The nerve cord is protected by the backbone. The brain is very complex. The frog can think, plan, and be taught to do simple things.

Reproductive System Frogs reproduce sexually. They are male and female The female releases the batch of eggs into the water and the male then fertilizes them in the water. The eggs stay in the water for up to two months before they hatch. Hundreds of eggs are laid, but only a few (100) hatch and only about 10 become frogs and only about 1-2 make it to adults. Eggs are good food for lots of animals (fish)