Frog Dissection Guide

External Structures Where would one find the nictitating membrane? What makes the cloaca unique as an excretory structure?

The Oral Cavity What is the purpose of the vomerine and maxillary teeth? How does the esophageal opening differ from the glottis? Where do they lead?

The Liver The liver is the large brown, 3-lobed organ seen here. What is its function? What other structures can you see here?

The Gall Bladder The Gall bladder looks like a small deflated balloon. It secretes bile. What role does bile play in the digestive process?

The Spleen The spleen is small and round like an apple. What organ do you see on its left? What important role does the spleen play as part of the immune system?

The Pancreas How is the pancreas important as both an endocrine and exocrine organ? Where, specifically, can it be found in your frog?

The Stomach What happens inside the stomach? Into what structure does the stomach lead? What happens there?

The Small Intestine The small intestine can be seen here. Why is it so long? How is it different from the large intestine?

The Large Intestine This frog’s large intestine is extremely full. Into what structure does it lead to for elimination? Why is it such an important organ for hydrostatic homeostasis?

Fat Bodies Why are fat bodies important structures for frogs? Why are they essential female frogs in particular?

The Heart The heart is located within what structure? Why are 3 chambers less efficient than 4?

The Lungs Notice the position of the lungs to the left and right of the heart. How do frogs breath differently than mammals?

The Bladder The bladder may be hard to find in your frog specimen. What are the names of the tubes that carry urine to the bladder?

The Kidneys How do a frog’s kidneys appear different from a mammals? What is the functional unit within the kidney called?

Sexing Your Frog: The Male Underneath the intestines and proximal to the kidneys, you can see two bean shaped testes. What process makes these organs so unique and important among all others?

Sexing Your Frog: The Female In female frogs you will may or may not see eggs, however you can always find oviduct (looks like noodles). Explain the role of the oviducts as reproductive structures.

The Dorsal Aorta From what part of the heart does this (the largest blood vessel) extend? Name 3 major arteries which branch off of the abdominal aorta.

The Vena Cava What part of the heart does the vena cava empty into? How is “blue” blood different from “red blood?”

Pop Quiz: Identify Structures A-N