The skeletal system of humans vs bugs.
The skeletal system of humans and bugs are fundamentally different, primarily because they belong to separate categories in the animal kingdom. Humans fall under the category of vertebrates, which are animals with an internal skeletal system, while bugs belong to invertebrates (arthropods, specifically), which have an external skeletal system. Here is a comparison between the skeletal systems of humans and bugs:
1. Type of skeleton: Humans have an endoskeleton, which is an internal skeletal system made of bones. Bugs, on the other hand, have an exoskeleton, an external skeleton made of a hard substance called chitin.
2. Function: Both the human endoskeleton and the bug exoskeleton serve as support structures for the body, providing protection for internal organs, aiding in locomotion, and facilitating muscular movements. However, the human endoskeleton also has the additional function of producing blood cells in the bone marrow.
3. Growth: The human endoskeleton grows along with the body throughout childhood and adolescence. Bones lengthen and expand in size as the individual matures, allowing for gradual growth. In contrast, the exoskeleton of bugs does not grow, so they must undergo molting in order to grow. They shed their old exoskeletons and then secrete a new, larger one, which hardens over time.
4. Number of segments: The human skeleton is divided into two main parts - the axial skeleton (consisting of the skull, vertebral column, and ribcage) and the appendicular skeleton (consisting of the limbs, including arms, legs, pelvic, and shoulder girdles). Each limb has several long bones connected by joints. Bugs have segmented exoskeletons, with their bodies divided into the head, thorax, and abdomen segments. Their limbs (usually six, but can vary depending on the bug) are also segmented and connected by joints.
5. Composition: The human endoskeleton is primarily composed of bone, which is an organic material made of collagen fibers and mineralized with calcium and phosphorus, giving bones their strength and rigidity. Bug exoskeletons are primarily made of chitin, a durable, lightweight, and flexible polysaccharide.
6. Weight support: The human skeleton is designed to bear weight and protect internal organs from the stresses of gravity. The structure of our bones allows for adequate support of all body weight, including additional forces from physical activities like jumping or running. Conversely, bugs rely on their exoskeletons for weight support, but they have a lower body-to-weight ratio compared to humans, reducing the need for robust weight-bearing structures.
In summary, the human skeletal system consists of an internal endoskeleton made of bones, which provides support, protection, and movement for the body while enabling continual growth. In contrast, bugs have an external exoskeleton made of chitin that must be molted for growth, providing the necessary support and protection for their bodies.