د "هډوانه" د بڼو تر مېنځ توپير

''' [[Exoskeleton]]s are external, as is typical of many [[invertebrate]]s; they enclose the soft tissues and organs of the body. Exoskeletons may undergo periodic [[moult]]ing as the animal grows. [[Endoskeleton]]s are internal, as is typical of many [[vertebrate]]s; they are usually surrounded by skin and musculature, though they often enclose vital organs. Endoskeletons are attachment points for musculature and act as leverage for movement, and in many animals contain [[marrow]], which produces blood cells. Skeletons may or may not be [[biomineralization|mineralized]] - human skeletons are calcified, while shark skeletons are cartilaginous - and may be jointed for flexibility and motility or rigid for structural strength.