Question

Muscular activity stimulate internal organs digestive and respiratory system. PHYSICAL EDUCATION​

Answer 1

Answer:

Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissue, with the other two being skeletal muscle and smooth muscle. It is involuntary, striated muscle that constitutes the main tissue of the wall of the heart

Answer 2

Explanation:

• The respiratory organ of the insects consists of a system of air-filled tubes, called the tracheae, which are in most cases in open connexion with the outside air through openings in the body wall, the spiracles.