Question

Four chambered heart is found in (a) Cobra (b) Tortoise (c) Salamander (d) Crocodile

Short answer

The correct answer is (d) Crocodile.

Step-by-step solution

Understanding the cardiovascular systems

Different animals possess different kinds of hearts based on the chambers they have. A four chambered heart is most advanced and is found in birds and mammals primarily. It separates oxygenated and deoxygenated blood completely, allowing for more efficient distribution of oxygen to the body.

Analyzing the options

The options give a snake (Cobra), a reptile (Tortoise), an amphibian (Salamander) and another reptile (Crocodile). Among these, the four-chambered heart is not found in snakes (Cobra) or amphibian (Salamander). The reptiles generally have a three-chambered heart but there are exceptions.

Identifying the correct answer

Among reptiles, crocodiles are unique to have a four-chambered heart. Thus, among the given options, only the Crocodile has a four chambered heart.

Key concepts

Four Chambered Heart

A four-chambered heart is a highly efficient structure found in mammals and birds. This type of heart features two atria and two ventricles. This configuration allows for the complete separation of oxygenated and deoxygenated blood, which enhances the efficiency of oxygen transport throughout the body. Efficient oxygen transport supports the high metabolic demands of warm-blooded organisms.

• The right side of the heart receives deoxygenated blood from the body and sends it to the lungs for oxygenation.
• The left side receives oxygenated blood from the lungs and pumps it to the rest of the body.

This separation prevents the mixing of oxygenated and deoxygenated blood. It ensures organs receive a constant supply of rich oxygenated blood, maximizing energy production. For animals with high metabolic rates, like birds and mammals, such a system is crucial for maintaining body temperature and active lifestyles.

Reptilian Heart Anatomy

Most reptiles possess a three-chambered heart. This typically includes two atria and a single ventricle. In this setup, there is some potential for mixing of oxygenated and deoxygenated blood in the ventricle. Reptilian hearts are still effective for their needs but suit the typically lower metabolic demands of cold-blooded animals.
Reptiles like turtles, lizards, and snakes usually show this structure. Despite being less complex than a four-chambered heart, it allows reptiles to function efficiently within their ecological niches.

• The right atrium receives deoxygenated blood from the body.
• The left atrium receives oxygenated blood from the lungs.
• The ventricle then sends blood to the appropriate destinations, albeit with some mixing.

The less precise separation between the two blood types reflects their lower energy and oxygen demands, which is suited to their environmental adaptations.

Crocodile Heart Structure

Uniquely among reptiles, crocodiles have a four-chambered heart. This is similar to mammals and birds, providing an efficient circulation system. Crocodilian heart anatomy includes two atria and two ventricles. This setup allows the complete separation of oxygenated and deoxygenated blood.
The crocodile's heart has an intriguing feature called the foramen of Panizza. This is a small opening that connects the two aortas leaving the heart. It allows blood flow adjustments between the heart's chambers and helps crocodiles stay submerged for long periods.

• Crocodiles can regulate blood flow, managing oxygen supply based on activity.
• The structure supports high metabolic demands during active hunting.

This adaptation allows crocodiles to maintain energy levels during both vigorous activities and rest phases, showing nature's remarkable evolutionary solutions for different lifestyles.