Question

A number of different vertebrates have adaptations for diving. For example, the structure of the cardiovascular and respiratory system of amphibians (frogs/salamanders) allows them to bypass their unventilated lungs. Compare the structure of the amphibian respiratory and circulatory systems to that of humans and explain how the organization of the amphibian’s circulatory and respiratory system are adapted to diving.

Answer 1

Ans . Amphibians (e.g. frogs) and humans have many comparable body systems, including the respiratory system.Both use lungs to take in oxygen and expel waste gases like CO2.There are differences in the way they breathe, and in the way frogs supplement their oxygen intake through their skin. Amphibians use their porous skin and lungs for respiration.

similarities between frog lungs and human lungs :- Frogs and humans both have a glottis that closes off the trachea when swallowing. They also have larynx that contains vocal cords, and bronchial tubes that divide into a pair of air sacs called lungs.

Differences in mechanism of respiration between frogs and humans :- Humans have a sheet of muscle called a diaphragm that is attached to the ribs and the bottom of lungs.When the diaphragm contracts, it expands the chest cavity and the difference in air pressure sucks air into the lungs. Frogs do not have a diaphragm, and instead they pump air in and out of lungs by expanding and contracting their throat sac.

Frogs have a moist, permeable skin, which can transfer gases such as CO2 and O2. Humans have dry skin that is impermeable to gas exchange, so almost all gas exchange takes place in the lungs. This indicates that human lungs must be more efficient than frog lungs.

Amphibian (e.g. frogs ) have a closed circulatory system. The frogs has a three-chambered heart (two atria and a ventricle). The right atrium receives deoxygenated blood from the veins. Oxygenated and deoxygenated blood have a tendency to mix within the ventricle that is responsible for pumping blood. The left atrium receives oxygenated blood from both lungs and skin.

Frogs have 3 circuits for their circulation, unlike humans who only have two. Like humans, however , frogs have a systemic circuit, which pumps oxygenated blood throughout the body. The pulmonary circuit moves blood to the lungs to pick up oxygen. Frogs also have pulmocutaneous circuit, where deoxygenated blood is transported to the skin to pick up oxygen and undergo gas exchange.

Frogs are better adapted to diving than other vertebrates because, in addition to its lungs for air breathing, it has the ability to exchange O2 and CO2 through its well-vascularized skin.