What does the chapter state about "For example physical activities are" in Digestive And Excretory System?
It passes through nostrils, pharynx, trachea and bronchi and reaches the lungs (inhalation).
For example, physical activities are based on motor movements and their co-ordination.
The four chambers are left and right atria (singular atrium) and left and right ventricles.
The required energy for movements and other activities is obtained from food.