PHYSIOLOGY OF GROWTH:
Growth is a complex phenomenom that involves different faculties:
1)physical growth
2)neural growth
3)lymphoid development
4)reproductive growth
The increase in growth that occurs in the body is due to 2 processes: tissue growth and tissue growth defferentiation
1)tissue growth: involves increase in number of cells(hyperplexia) and increase in size(hypertrophy)
2)tissue growth differentiation: other wise refered to as function maturation.in this instance some structures are eliminated while some others are added to acquire or provide nomal functioning.part of the physiologic mechanism that does this is apoptosis(cell death).
NOTE:in human growth does not take place through out life time.
GROWTH PATERN:
1)physical growth:there are two period of rapid growth in humans.
A)from the infant stage which appears to be a continuation of ths foetal growth.
B)at late puberty the female tends to grow faster earlier while the male comes later and proceeds longer.
2)neural growth:attains 80% at the age 4years and between 8 and 10 years 100%.at this stage nutritional deficiency affects neural development there is no increase in number of neurons but rather there is an increase in neuronal size.
3)lymphoid development:there is a rapid lymphiod growth from age 10 which tends to be completed at 12
4)reproductive growth:rapid growth in reproductive structure including the gonads occurs at puberty due to the influence of gonadotropines from the anterior putuitory.
FACTORS THAT AFFECTS GROWTH
1)genetics factor
2)diet
3)hormones
4)state of health
1)Genetics factor: appears to be the most important determinant of an individual height
2)Diet: malnutrition might hinder growth of an individual therefore balanced diet such as protein rich,minerals,CHO etc are all needed for growth.
3)state of health: illness during growing stages will retard growth due to protein catabolism.
However from recovery,the individual experiences catch up growth.
Growth defect:
1)turner syndrome
2)gigantism
3)psychosocial dwarfism
4)dwarfism
