Question

1. Muscle can attach to bone either via tendon or attach in a___________manner.

2. Which class of lever will always represent the following: a muscle must exert more force than the force of resistance

   (weight lifted).

Answer 1

• Muscle can attach to bone either via tendon or attach in a direct manner.

EXPLANATION :

Muscles can attach to bone directly during contraction, where the epimysium of muscle attaches to the perimysium of the bone.

Muscle attches to bone indirectly via tendon. Here the connective tissue of muscle form a tendon at the end and inserted into bone.

• Which class of lever will always represent the following: a muscle must exert more force than the force of resistance - Type 3 lever.

EXPLANATION :

Lever is a machine which consists of a rigid bar supported at fulcrum. A force called effort force applied at one point on the bar inorder to move resistance force located at some other point of lever.

Muscles and bones of human body together act as a lever.

There are 3 types of lever-

Type 1-Fulcrum between effort force and resistance force.

This type of liver are used to maintain posture

Eg:-At the atlantoaxial joint(act as fulcrum) , skull is maintained by the 1st vertebrae.

Type 2- Resistance force is between effort force and fulcrum. This has a mechanical advantage.

Eg: During pushup- toe tip acts as fulcrum, gravitation is the resistance force and effort force given by the arm.

Type 3- Effort force is between resistance force and fulcrum. There is no mechanical advantage in this type.The effort force or the force we are applying is more than resistance force.

Eg:Flexed arm: elbow joint acts as fulcrum, biceps provide effort force and the weight of forearm is the resistance force.