Toad ‒ Anatomy

Frogs are ectothermic animals which means they depend on the heat of their environment to keep their body temperature stable. They have closed circulatory systems with a three-cavity heart that has 2 atria and 1 ventricle. The blood that flows through the heart on both of the circulations (pulmonary and systemic) has approximately the same concentration of oxygen. This is because frogs breathe through lungs but they also perform gas exchanges through their skin and through the bucopharyngeal (throat) region. The cutaneous respiration (breathing through their skin) might occur if the frog is in land or in water. This adaptation allows the frog to navigate between both habitats. The bucopharyngeal respiration is responsible for 1 to 7% of all gas exchanges that are made. Both cutaneous and bucopharyngeal are less efficient than lung respiration because they are constant and they do not change if the metabolism changes. The brain is divided into 3 subdivisions: the forebrain, the midbrain and the hindbrain. The forebrain is responsible for the visceral functions while the midbrain processes sensory information, and the hindbrain performs basic functions such as heart rate and mechanisms of respiration.