Number of ribs: The human rib cage typically consists of 12 pairs of ribs (24 ribs in total), while the number of ribs in animals can vary depending on the species. For example, animals like dogs and cats have 13 pairs of ribs (26 ribs in total), while some other mammals may have as many as 17 pairs.
Shape and orientation: The shape and orientation of rib cages can vary among animals. In humans, the rib cage is relatively wide and flat, with the ribs sloping downwards from the spine. This provides space for the lungs and heart to expand during breathing. In contrast, animals like quadrupeds (e.g., dogs and cats) have a more cylindrical rib cage with ribs that are oriented more horizontally to support their weight-bearing posture.
Sternum: The sternum, or breastbone, is a flat, elongated bone that connects the ribs in the front of the chest. While both animals and humans have a sternum, it can differ in terms of shape and flexibility. In humans, the sternum is relatively inflexible and forms a rigid structure, providing protection for the vital organs. In contrast, animals like quadrupeds may have a more flexible sternum, allowing for increased movement during locomotion.
Mobility of the rib cage: The rib cage in humans is relatively mobile and flexible. The movement of the ribs and the diaphragm muscle is essential for breathing, allowing the lungs to expand and contract during inhalation and exhalation. In contrast, the rib cages of some animals, such as reptiles, may be less flexible, restricting their ability to breathe deeply.
These differences in rib cage structure and mobility reflect the diverse adaptations that have occurred in different animal species to meet their specific functional needs and environmental requirements.