Organ System of Frog Homework Help: Respiratory system of frog: Inside water, frogs respire through skin by the method of cutaneous respiration. The dissolved oxygen present in the water is exchanged through the skin by diffusion. And on land, the buccal cavity (nostrils), skin and lungs aid in respiration. The lungs are a pair of pink-coloured sac-like structures present in the thoracic region. Air enters through nostrils and then to lungs where exchange of gases takes place. This type of respiration through lungs is defined as pulmonary respiration. During aestivation and hibernation periods, respiration takes place through skin.
Organ System of Frog Homework Help
Circulatory system of frog:The circulatory system is closed-type. The circulatory system consists of blood vessels, three-chambered heart and blood. Additionally, a lymphatic system comprising lymph, lymph nodes and lymph channels is also present. The heart of the frog is covered by a membrane called pericardium and consists of two upper auricles and one lower ventricle. A triangular structure called sinus venosus joins the right atria. The blood is supplied to different parts of the body by arterial system (arteries) and the deoxygenated blood is collected by the venous system. The right atrium receives blood through vena cava and pushed down to ventricles which open into sac-like structure called conus arteiosus on the ventral side of the heart. The frogs have special venous connection from liver and intestines known as the hepatic portal system and likewise, in kidneys and other lower parts of the frog is known as renal portal system.
The blood of frog is composed of plasma and cells which includes red blood cells (RBCs), white blood cells (WBCs) and platelets. The RBCs are nucleated and carry a red colour pigment called haemoglobin, which is responsible for carrying oxygen from the lungs to the different parts of the body. The circulation of blood is achieved through constant pumping action of the heart. The lymphs lack RBCs and few proteins.
Excretory system of frog: The frog has well-developed excretory system with a pair of kidneys, ureters, urinary bladder and cloaca. The kidneys are made up of numerous structural and functional units called nephrons. In male frogs, the ureters arise from each kidney and open into cloaca. While in female frogs, the ureters and oviduct open separately into cloaca. The nitrogenous wastes are filtered through nephrons and collected in the thin-walled urinary bladder, which opens exteriorly into cloaca. Since, frogs excrete urea, it is also known as urotelic animal.