Question

Describe the structure of the heart of a rabbit. Draw a neat labelled diagram of LS of heart.

Answer 1

Hint: Blood is an essential body fluid in the body of animals and humans. It helps in transportation of various nutrients and oxygen to the body cell and carry out the metabolic waste away from the cell.

Complete answer:
The heart of the rabbit is four chambered in which there are two auricles and two ventricles. The auricles are larger than the ventricles. The auricles are delicate compared to the ventricles. The interauricular septum detach the right and left auricle. The aperture found in the right ventricle is known as sinu-auricular aperture. The pulmonary veins open in the left auricle through an oblique aperture. The two auricles are detached from the ventricles by the help of auriculo- ventricular septum. The right and left auricle opens into the ventricle through auriculo ventricular aperture. This aperture is guarded by auriculo ventricular valve. This valve consists of four flaps. Chordae tendineae are thread-like chords which are attached to the muscular wall of the ventricle at each end. Conus arteriosus is the basal, broad and thick walled portion of the truncus arteriosus. Ventral aorta is the former, delicate and contracted portion of the truncus arteriosus.
There is a spin-like valve found in the conus arteriosus and the valve separates the lumen of the conus arteriosus into a left cavum pulmocutaneous and right cavum aorticum. The blood entering the cavum pulmocutaneous enters through the pulmocutaneous arches. The ventral aorta divides into lateral aortae. Each lateral aorta is divided into two arch: carotid arch and systemic arch.

Note: Double circulation is found in rabbits. Double circulation means blood passes twice or two times through the heart in one complete cycle. It is mostly seen in amphibians, reptiles, birds and mammals.