Summary
Highlights
The video introduces the dissection of a bullfrog, focusing on internal anatomy and differentiating between male and female frogs.
The most obvious organ is the large, three-lobed liver, which produces bile for digestion. It is removed to reveal other organs.
Behind the liver are the lungs, described as deflated balloon-like structures. Frogs primarily breathe through their skin, making their lungs relatively underdeveloped.
The gallbladder stores bile from the liver. The digestive system begins with the esophagus connecting to the stomach, which has a pyloric sphincter separating it from the small intestine, controlling the flow of digested food.
The pancreas, a string-like structure near the stomach, aids in digestion by releasing juices into the small intestines. The small intestine is long but narrow, followed by the wider large intestine, which connects to the cloaca.
Yellow, finger-like fat bodies store fat, with their size indicating the frog's fat reserves. The spleen, a kidney bean-shaped organ, recycles red blood cells and fights bacteria.
The kidneys, paired structures along the frog's back, filter blood and produce urine, which is stored in the deflated balloon-like urinary bladder before exiting through the cloaca.
External features like the size of the tympanic membrane compared to the eye can indicate sex. A larger tympanic membrane and big thumb typically suggest a male.
Internally, male frogs have paired, kidney bean-shaped testes on top of the kidneys. Female frogs have ovaries containing black and white eggs and oviducts, which facilitate egg release through the cloaca.
The heart of the frog is a three-chambered organ with a triangular shape, consisting of two atria and one ventricle.