CBSE Class 11-science Answered
Expert Answer
Skeletal system includes bones, cartilage and joints.
Functions of the skeletal system: Support and shape, protection, movement, leverage, formation of blood cells and storehouse for minerals.
|
COMPONENT OF THE SKELETON |
DESCRIPTION |
|
Skull
|
Divided into head bones and facial bones. Head bones-8, Facial bones- 14 |
|
Vertebral column
|
Composed of 26 ring-like bones called vertebrae. Has a characteristic S-shaped curve which helps in balancing the body. Cervical vertebrae- 7 bones, Thoracic vertebrae- 12 bones, Lumbar vertebrae- 5 bones, Sacrum- 5 bones, Coccyx- 4 bones |
|
Ribs
|
Each rib articulates with a thoracic vertebra. True ribs- 7 pairs, False ribs- 3 pairs, Floating ribs- 2 pairs |
|
Sternum
|
Long, flat and strong bone in the centre of the chest. Holds the ribs in place. |
|
Bones of the limbs
|
Upper arm bone- Humerus, Forearm bones- Radius and Ulna Hand- 8 carpals, 5 metacarpals, 14 phalanges Leg bone- Femur, Bones of lower limb- inner Tibia and outer Fibula, Knee bone- Patella Foot- 8 tarsals, 5 metatarsals, 14 phalanges |
|
Bones of the girdles
|
Each pectoral girdle consists of a collar bone or clavicle and the shoulder blade or scapula. Pelvic girdle- Ilium, Ischium and Pubis |
Cartilage is a connective tissue with a solid matrix and widely spaced cells found between two or more bones. It smoothens the bone surface, acts like a cushion and prevents rubbing of bones against each other.
The point at which two separate bones meet is called a joint.
Concept Videos
ANSWERED BY EXPERT ANSWERED BY EXPERT ANSWERED BY EXPERT ANSWERED BY EXPERT ANSWERED BY EXPERT ANSWERED BY EXPERT ANSWERED BY EXPERT ANSWERED BY EXPERT ANSWERED BY EXPERT ANSWERED BY EXPERT
