Skeleton Flashcards
Functions of the skeleton
~ Support
~ Protection
~ Movement
~ Production of blood cells
Structure of the Human Skeleton
It has 206 bones and is divided in two sections ; Axial skeleton and Appendicular skeleton
Skull
Fused together
Spine
~ Consists of 33 bones called the vertebrae
~ There is a disc of cartilage between each vertebrae
Ribcage
Consists of the sternum and 12 pairs of ribs
Vertebra
~ Top 24 vertebrae are held together by ligaments and can slightly move
~ The last 9 are fused together and there are no discs between them, no movement occurs here
Region and number of vertebrae
~ Cervical = 7
~ Thoracic = 12
~ Lumbar = 5
~ Sacrum = 5
~ Coccyx = 4
Parts of appendicular skeleton
~ Pectoral girdle : Connects vertebral column and the arms
~ Pelvic girdle : Composed of two halves of the hip joined to the sacrum
Cartilage
~ Function : Shock absorber
~ Made of fibrous protein called collagen
~ Slower to heal than bone
~ No blood vessels or nerves
~ Found in the pinna of the ear, the nose, the trachea, the discs between the vertebrae and it covers the end of bones
What is a long bone?
Femur, tibia, fibula, humerus, radius and ulna
Parts of the long bone
~ Compact bone
~ Spongy bone
~ Medullary cavity
Compact bone
~ Formed from many minerals and proteins
~ Found in the diaphysis (shaft) of the bone
~ Function : Calcium gives strength and protein gives flexibility
Spongy bone
~ Consists of red bone marrow
~ Found in the epiphysis (each end) of the bone
~ Gives strength to the skeleton
Medullary cavity
Function : Produces yellow bone marrow
Function of bone marrow
~ Red bone marrow : Produce blood cells
~ Yellow bone marrow : Store fat
Bone growth
Osteoblasts (anabolic) : Bone forming cells which produce the protein collagen
Growth plate
~ The increase in the length of a bone is due to a growth plate made of cartilage
~ Found in our long bones between the diaphysis and the epiphysis
Bone development
~ Osteoclasts (catabolic) : Bone digesting cells
~ They deposit calcium from the bones that were broken down into the blood
Renewal of bone
- Physical activity : Causes bones to become thicker and stronger
- Hormone level : Growth hormone and sex hormones increase the size of bones
- Diet : Rich in calcium and vitamin D for strong bones
Joints
Where two or more bones meet
Immovable joints
~ Known as fixed or fused joints e.g. skull, pelvic girdle
~ Provide strength, support and protection
Slightly movable joints
Joints between the vertebrae, are slightly movable
Freely movable joints / Synovial joints
~ Ball and socket : Bone can move in all directions e.g. shoulder and hip
~ Hinge joint : Can move in one direction only e.g. elbow and knee
Synovial fluid
Is produced on movable joints to lubricate and reduce friction