The fact that the structure and function of the human body change with age may seem obvious, but it is often overlooked . Some of the examples are as follows:
1. The liver is relatively much larger in the child than in adult. In the infant, the lower margin of the liver extends inferiorly to a lower level than in adult. This is an important consideration when making a diagnosis of hepatic enlargement.
2. At birth, all bone marrow is of red variety. With advancing age, the red marrow recedes up the bones of the limbs so that in the adult it is largely confined to the bones of the head, thorax, and abdomen.
3. In the infant, the bones of the skull are more resilient than in the adult, and for this reason fractures of the skull are much more common in the adult than in young child.
4.The urinary bladder in the child cannot be accommodated entirely in pelvis because of small size of pelvic cavity. As the child grows , the pelvis enlarges and the bladder sinks down to become a true pelvic organ.
5.Lymphatic tissues reach their maximum degree of development at puberty and thereafter atrophy, so the volume of lymphatic tissue in older persons is considerably reduced.