Support And Movement In Man
14.6.5 functions of tendons and ligaments in relation to movement
functions of tendons – Many of the muscles that extend your toes are actually in your lower leg. The tendons from these muscles travel over the front of your ankle, across the upper surface of the foot bones, and attach to the bones of our toes. Straps of ligaments over the ankle hold these tendons in place and allow them to bend at a right angle and elevate foot and toe.
Fig 14.21 tendons and ligaments
You have already studied above that the ends of the muscles are drawn out into tendons. These are straps of connective tissues which attach each end of the muscle to the skeleton. One end of the muscle is attached to a non-moving bone of the skeleton, through tendon. The other end is attached to the movable bone close to the joint.
The relevant bones of the joints are held together by ligaments. These are strong flexible bands of connective tissues. The ligaments prevent dislocation during normal movement. They also hold tendons in place and control their direction.
14.6.6 Joints; location and their movements
When two bones meet, a joint is formed. They are movable or immovable.
- The joints between the bones of the skull are fixed. They do not show any movement. In the case of the vertebrae. Only a very limited movement can occur.
- The ball-and-socket joints of the shoulder and the hip allow movements in three directions; forwards, backwards and sideways.
- The hinge joints of the elbow and knee allow movement in only one plane (fig. 14.23). the surfaces at the heads of the bones which move over each other are covered with a tough, slippery and smooth cartilage. This together with a liquid formed in the joint allows friction. Free movement.
Practical works: to examine parts of human skeleton.
Examine human skeleton and answer the following questions
- Categorize numbered bones of:
(Write numbers only)
- Axial skeleton. Write down
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- Appendicular skeleton.
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- How many ribs are attached to the vertebral column? ——————————————————–
- Name the bone, by means of which fore arm is attached to the vertebral column.——————–
- Encircle hinge, ball and socket joint on the given diagram of human skeleton (fig. 14.18).