Understanding Body Types and Their Developmental Growth

Body Types can be graded on three components:

• Endomorphy: Refers to the predominance of curves and visceral development.
• Mesomorphy: Refers to the predominance of muscle and bone. Subjects are relatively strong.
• Ectomorphy: Highlights the prevalence of poor muscle development, resulting in greater fragility. Subjects typically have long and thin limbs.

In relation to the question of heritage concerning body type, there seems to be a consensus to accept its inherited character, manifesting at an early age.

The Growth of Different Body Systems

Nervous System

The nervous system shows growth and maturity very quickly. It is likely that after 7 months of age, nerve cell formation has not yet completed; however, there seems to be a predetermined sequence in the development of nerve bundles and nuclei. At 9 months postpartum, the brain shows a weight equivalent to 50% of the adult brain, reaching 75% of its final weight by 2 years. Although the brain size at birth is close to that of an adult, its operation is rudimentary, showing asynchrony between structure and function.

Skeletal System

Bones originate as a cartilaginous soft system that undergoes ossification and hardening. The ossification process begins during the prenatal period, between the 2nd and 4th month, and continues through adolescence in certain bones. Girls finish their bone growth earlier than boys, approximately between 18 and 20 years. Bone growth problems can occur in many cases due to inadequate blood supply of nutrients, altering the growth process and damaging the cells. As for bone growth data, we must note that the ribs ossify quickly, the feet ossify before the hands, the knee epiphyses develop later, the pelvis is fully ossified at about 20 years, the vertebral bodies at 25 years, and the clavicle in men and women at around 26-27 years, marking the endpoints of ossification.

Fatty Tissue

The thickness of subcutaneous fat from birth increases steadily, reaching its peak around the 9th month, then gradually tapering off until the child is 6 to 8 years old, when it increases again. Increased localized fat in the trunk extends into adulthood in both sexes. In many children, there is a preteen fat outbreak. There are sex differences in the development of fatty tissue; girls show a greater increase that is accentuated during puberty. In girls, fat accumulates in the hips, while in boys, it accumulates in the abdomen.

Muscle Tissue

Muscle tissue decreases during childhood but increases during adolescence, more so in boys than in girls.