The human endocrine system controls the growth process. Growth involves increases in height, weight, cell number, and bone length as well as changes in body shape and function through cell differentiation and maturation of the mind and emotions. Growth occurs in stages from infancy to childhood to adolescence to adulthood to old age, with differences in growth rates between boys and girls during adolescence. Puberty triggers secondary sex characteristics through the release of hormones like testosterone and estrogen.

1. Chapter 5
Growth

2. Which part of the body controls
the growth process??

3. 5.1 Pattern of Human Growth
Definition of Growth
 Increase in
◦ Height
◦ Weight
◦ Number of cells
◦ Length of bones
 Change in body shape
and function
 Cell differentiation
 Maturity of Mind and
Emotion

4. Stages of Human Growth
(Based on Growth rate)
Stage 1 – Infancy Stage 4 – Adulthood
Stage 2 – Childhood Stage 5 – Old age
Stage 3 –
Adolescence

5. Human Growth Curve

6. Differences in Gender
Stage 1 – Infancy (0 – 2 years)
 Same
Stage 2 – Childhood (2 – 12/14 years)
Boys faster than girls
Stage 3 – Adolescence (12 – 14 years)
Girls faster than boys
Stage 4 – Adulthood (14 – 19 years)
Continue development
Boys become taller than girls due to
longer development period

7. Growth curves of Boys and Girls
based on height

8. Puberty
 Reproductive organs start to become
mature
 Secondary growth occurs in males and
females due to the release of hormones

9. Secondary growth in Males
 Stimulated by testosterone
 Boys usually reach puberty at an
average age of 13 years.
 Testis starts to produce sperms
 Shoulder and chest become broader
 Voice breaks and deepens
 Growth of pubic hair and beard

10. Secondary growth in Females
 Stimulated by Oestrogen and Progesterone
 Girls
tend to mature two years earlier than
boys (average age of 12)
 Breasts develop
 Hips widen
 Undergoes the menstrual cycle

11. Secondary growth in
males and females
Characteristics Male Female
Voice Low and Coarse Soft and
Pleasent
Hair Beard, Pubic Pubic
Bones Lengthen -
Fat deposit - Breast and
Pelvis
Muscles Increase and -
Bigger
Body Shape Broader shouler Broader chest
and Muscular and Pelvic Bone

12. Growth retardation

13. Primordial dwarfism

14. Excessive Growth Hormones