Factors Affecting Growth and Development
The following factors affect the growth of living things:
Nutrition refers to the food we eat and how our body uses it. The availability of appropriate nutrients in diet plays an important role, in the growth of an organism.
Hormones are chemical messengers, produced by the endocrine glands, situated in different parts of the body.
Growth Hormones: These are produced from the pituitary gland, which is located at the base of the midbrain. Thepituitary gland secretes an important hormone called pituitary hormones, or growth-stimulating hormones (GSH) which determines how tall an individual can be.
Over secretion of this hormone before maturity leads to a condition called Gigantism. The development of long bones under secretion in early life results in a condition called Dwarfism. Over secretion in adults causes a condition called Acromegaly, a condition characterized by coarse facial features, enlarged jaw, nose, tongue, and excessively large hands and feet.
Heredity is the passing on or transmission of traits or characteristics from parents to offspring. Genes transmit features from parents to their offspring, therefore genes can transmit the height of parents to the offspring, thus tall parents are likely to have tall children.
Some diseases are inherited by the offspring which will definitely affect the growth of the child, for example, sickle cell anemia.
Good personal health enables us to grow and develop normally to full capacity. When there is an absence of good health or when a person suffers from a disease, growth, and development may be slowed down.
5. Exercise and Rest:
Exercise has a very good effect on health as well as growth, its effects are noticeable in the development of muscles. It makes the muscle stronger, also through exercise, we can get rid of waste substances which if left in the body can affect our health, and consequently our growth.
During rest, the body is relaxed and this may induce sleep and through this, strength will be regained and this enables us to grow.
1. Define the following terms:
2. Outline 4 (four) characteristic features of adolescence.
3. List 4 (four) stages of developmental changes.
4. List 5 (five) factors affecting growth.
5. Outline five (5) physical changes that occur in girls at puberty.
6. List the type of hormones secretes by the following glands:
(i) Pituitary gland (ii) Thyroid gland.
Reading assignment: spectrum basic science for junior secondary schools, book 2. Pages 67 – 72.