Question

(a) How does muscles help us in movement?

(b) Name the tissue that

1. Helps the heart to work throughout life.
2. Controls movement of food in the alimentary canal
3. Lets us move our hand to write.

Answer 1

(a) Muscles contain special proteins called contractile proteins, which contract and relax to cause movement.

(b) I. Cardiac muscle - The muscles of the heart show rhythmic contraction and relaxation throughout life. These involuntary muscles are called cardiac muscles.

II. Smooth muscle – also called involuntary muscles control the movements that we cannot control at our will. These help in the movement of food in our alimentary canal.

III. Skeletal muscle - Muscles present in our limbs move when we want them to, and stop when we so decide. Such muscles are called voluntary muscles skeletal muscles as they are mostly attached to bones and help in body movement.