 |
| Summary |
|
 Movements and locomotion takes place as a result of co-operation between the muscle and skeletal system, hence the study of both is necessary. |
| |
|
Skeletal system in humans is formed by bones and cartilages. It helps in protection of delicate visceral organs, mechanical support, movements etc. |
| |
|
Human skeleton is divided into axial and appendicular skeleton. |
| |
|
Axial skeleton is formed of skull, vertebral column, ribs, hyoid apparatus and sternum. |
| |
|
Skull is dicondylic. First and second vertebra are modified into atlas and axis vertebra respectively. |
| |
|
Appendicular skeleton includes pectoral girdles, pelvic girdles and bones of limbs. |
| |
|
Pectoral girdle is formed of two bones scapula and clavicle but the pelvic girdle is formed of only one innominate bone. |
| |
|
Each of upper limb and lower limb consists of 30 bones. |
| |
|
Skeletal connective tissue includes bones and cartilage. |
| |
|
Cartilage is formed of a flexible matrix secreted by chodroblasts in the lacunae. |
| |
|
A bone has dense and inflexible matrix formed of proteinacous matrix of ossein secreted by bone cells called osteocytes. |
| |
|
Joint is the meeting place of two bones by the ligaments. Joints are of 3 types- sutures, symphyses and synovial joints. |
| |
|
Sutures are immovable joints found between skull bones. Symphyses are slightly movable joints. Synovial joints are freely movable joints. |
| |
|
Movements are peculiar characteristics of the living organisms, and takes place at the skeletal joints. |
| |
|
There are many types of movements such as angular movements, gliding movements, rotation movements etc. |
| |
|
Arthritis and osteoporosis are two very common skeletal disorders. |
| |
|
Arthritis is characteriised by inflammation and painful joint and osteoporosis is characterised by decreased activity of osteoblasts. |
| |
|
Striated muscle fibres have properties like excitability and contractibility. These are stimulated by a stimulus, which results in muscle contraction. |
| |
|
Most accepted theory of muscle contraction is sliding filament theory . |
| |
|
Many physical and biochemical changes occurs during muscle contraction. |
| |
|
The energy for the contraction of the muscle is provided by ATP molecules. |
| |
|
Skeletal muscles in vertebrates are of two types, namely red or slow muscle or white or fast muscle. |
| |
