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Growth And Its Measurement

Methods Of Measuring Growth

Supine Length (unable to stand → infant's length)

Standing Height

Body Mass → Amount of Organic Matter [Dry Mass → Plants]

Absolute Growth and Growth Rate

Advantages and Disadvantages of Cross-Sectional Study

Longitudinal Study

Relatives rates of growth of tissues and organs from birth to adulthood

Puberty

Physical And Endocrine Changes Associated With Puberty

The Role Of Hormones In Controlling Early Growth

Table 16-3-1: Summary of hormones controlling growth


Name of Hormone

Site of Release

Actions

Somatotropin

Anterior pituitary gland

Stimulates mitosis, protein synthesis

Thyroxine

Thyroid gland

Stimulates rate of metabolism

Gonadotrophins

Anterior pituitary gland
(situated under brain)

 

  - FSH

 

- Development of follicle/egg cells and oestrogen secretion by follicle cells in ovaries

  - ICSH

 

- Spermatogenesis in testes

  - LH (females)

 

- Triggers ovulation, forms corpus luteum, thickens uterus lining, produces milk in breasts

  - LH (males)

 

- Secretion of testosterone by testes

Oestrogen

Ovaries

- Growth of 2° sexual characteristics
- Thickening of uterus lining

Progesterone

Corpus luteum

- Growth of breasts
- Increases blood supply to uterus lining

Testosterone

Testes

- Growth of 2° sexual characteristics
- Sperm production

Table 16-3-2: Changes associated with puberty


In Boys

In Girls

Hormonal Stimulation

In Boys

In Girls

Testes

Ovaries, Oviduct,
Uterus, Vagina

ICSH (boys)
FSH (girls)

Growth hormones

Testosterone

Oestrogen

Body growth

Breasts

 

Growth hormones

Testosterone

Oestrogen + Progesterone

Facial Hair, Larynx

Pelvic girdle

 

 

Testosterone

Oestrogen

Pubic and axillary (underarm) hair

 

First menstrual flow (menarche)

 

 

 

Oestrogen + Progesterone