Different sections of the vertebrae and no of bones in each
Cervical- 7 bones
Thoracic-12 bones
Lumbar- 5 bones
Sacral- 5 bones
Coccyx- fused
-They affect the overall height
- Eg legs & arms( femur & humerus)
-They act as a lever, blood cell production
Short Bones
Type of Bones
- Smaller
- Eg. feet & hands ( phalanges)
-Weight bearing, support & stability
Seasmoid Bones
Type of Bones
- Specialised function, usually found within a tendon
- Eg. Patella
- Smooth surface for the tendon to slide over
Flat Bones
Types of Bones
- Forms protective surface
- Eg. Skull (cranium)
-Protective, large surface for muscle attachment
Irregular Bones
Types of Bones
- Specific Function
- Eg. Vertebrae
- Protection, Muscle attachment
Areas of Skeleton
Axial: Cranium (+facial bones), Thoracic cage (sternum & ribs), Vertebral column
Appendicular: upper limbs, lower limbs, shoulder girdle, pelvic girdle
Spine alignment & postural deviations
Neutral spine alignment: 33 vertebrae have an S shape
Scoliosis: Abnormal curve of spine to left or right (lateral curvature), affects thoracic region, inherited
Kyphosis: Excessive outward curving of thoracic region, caused by poor posture also deformities of the spine
Process of Bone Growth
Ossification: process of bone formation
Osteoblasts: cells that bring calcium to the bone helping it grow, more exercise increases calcium stores less likley to develop osteoporosis
Osteoclasts: cells that remove bone by dissolving old/damaged bone mineral, makes space create new bone tissue
Epiphyseal plate: (growth plate), at the end of long bones, when bone fully formed the head fuses with shaft creating epiphyseal line.
Function of the Skeletal System 1-4
1. Supporting Framework: bones give you shape framework for soft tissue
2. Protection: protect vital tissue & organs eg. cranium (brain), vertebrae (spinal cord)
3. Attachment for Skeletal Muscle: provides surface for the muscle to attach, tendons attachthe muscle to bone (typically flat)
4. Blood Cell Production :Bone marrow found in bones red & white blood cells, produced to replace dying cells
Function of the Skeletal System
5-8
5. Mineral Storage: bones store calcium (muscle contraction & bone repair) , phosporus ( too little causes pain+fatigue)
6. Leverage: muscles contract to pull the bones creating movement
7. Weight bearing: bones are strong & will support wight of body
8. Reduce Friction across joints: synovial fluid in the joints prevent bone rubbing together
Joints
Place where two or more bones meet, without joints our bodies wouldnt be able to move
Types of Joints
Fibrous- joints that can’t move,bones interlock + overlap eg. cranium
Cartilaginous- can only move a little, reducing friction between bones, absorbs heavy loads eg. vertebrae, between sternum + ribs(allows CPR)
Synovial- bones move freely, most mobility, eg. hips, shoulders, knees
Synovial Joint structure
Joint capsule- outer sleeve, holds bone in place and protects joint
Bursa- small synovial fluid sac, cushions between tendons and bone to prevent friction
Articulate cartilage- provides smooth slippery surface at end of bones prevents friction, shock absorbers
Synovial membrane- capsule lining that releases sf
Synovial fluid- viscous liquid lubricates joints, prevents friction, provides nutrients to ac
Ligaments- attach bone to bone
Types of Synovial Joints
1-3
- Ball & Socket- most moveable, they can move in all directions e.g hips, shoulders
- Hinge Joint-works like a hinge on a door, can only move in 2 directions e.g knee, elbow
3.Pivot Joint- allows rotation e.g atlas+axis of vertebrae (C1,C2)
Types of Synovial Joints
4-6
- Gliding Joints- little movement in all directons e.g hand between carpals
5.Saddle Joints- only joint in the body in base of thumb
6.Condyloid Joints- little movement in all directions, tendons prevent rotation e.g wrist
Skeletal Responses
- Stimulates increased mineral uptake (calcium)- makes bones stronger + denser, important for weight bearing exercises
- Produces more Synovial fluid- increasing flexibility of joint, increases nutrients to ac
Skeletal Adaptations
- Increase bone density, less likley to suffer fractures
2.Increased ligament strength, reduces risk of dislocation & increases flexibility - Increased thickness of articular cartilage
Additional Factors
Arthritis
Arthritis- inflammation withinh sj causeing pain
Osteoarthhritis- most common, caused by wear and tear, causing reduction in cartilage & bones rubbing
EE- produces more sf, provides important minerals to cartilage
Rheumatoid- inflammation of joint so they become painful + swollen
EE-
Additional Factors
Osteoporosis- weakening of bone, causing by lack of Vit D & calcium
EE- promotes uptake of minerals in bone, increases bone density
Age- bones slowly lose mineral density & become more brittle, weight training as a child can damage (growing) growth plates which can result in stunted growth.
