Skeletal system

List the functions of the bone

• Support

• Protection

• Leverage

• Storage

• Blood cell formation

Describe cancellous bone

Light and spongy

Dense and heavy bone

Compact bone (cortical bone)

What is inside a cancellous bone

• Trabeculae (randomly arranged)

  • Between those spaces it contains bone marrow

Describe a compact bone

• Shafts of long bone and outside layer of all bones

• Made from osteons that run lengthwise with the bone

Describe the periosteum

• Membrane that covers outer surfaces of bones

  • Outer layer = dense irregular CT with fibroblast

  • Inner layer = osteoblasts

Describe the endosteum

Membrane that lines the hollow interior surfaces of the bones

• contains osteoblasts

Describe osteoblasts

• Produce bone

  • Harden through ossification

Describe osteoclasts

Remove bone

Describe volksmanns canals

• channels in the bone that contain blood vessels

• Joined with blood vessels in the Haversian canals

Describe blood supply to bone

• Nutrient foramina

  • Contains large nerve, blood and lymph vessels

Describe red bone marrow

• forms blood cells (hematopoietic)

• Majority of bone marrow in young animals

Describe yellow bone marrow

• Consists of adipose tissue

• Common in adult animals

• Revert back to red bone marrow is needed

Mechanism of bone formation

Endochondral and intramembranous

Describe endochondral bone formation

Grows into and replaces cartilage

what is intramembranous bone made from

Develops from fibrous tissue membranes

List the steps of endochondral bone formation

Primary, secondary and epiphyseal plates

Describe primary growth

• Bones develop in diaphysis

• Cartilage is removed as bone is created

Describe secondary growth

Develop in the epiphyses of the bone

Describe the epiphyseal plates

Cartilage located between diaphysis and epiphysis of bone

• Sites where new bone develops to allow long bones to lengthen

How to bones get longer

• new cartilage is added to the epiphyseal side of the growth plate

• Cartilage replaced by bone on the diaphyseal side of the growth plate

Describe endochondral bone formation

Bone has reached full size, the epiphyseal Plates completely ossify

Describe how intramembranous forms

• Happens in skull bones

• Membrane made up of fibrous tissue

  • Bone forms in the fibrous tissue and ossification centres

List the four basic shapes of bones

• Long

• Short

• Flat

• Irregular

Describe the condyle

Large, round articulated surface

Describe the head of a bone

Spherical articular surface on the proximal end

• joins with the shaft of the bone at the neck

Describe the facet of the bone

Flat articular surface

Describe the processes for bone features

Projections off a bone surface

Describe the foramen

Hole in the bone

Describe the fossa

Depressed area on the surface of a bone

Describe fibrous joints

Immobile

Describe cartilaginous joints

Provide some movement (back and fourth)

Describe synovial joints

Lots of movement (Ligaments)

Types of synovial joints

Hinge, gliding, pivot, ball and socket

Describe hinge synovial joint

Flexion and extension

Example: elbow

Describe the Gliding synovial joint

• Flat joint surfaces

• Flexion and extension

• Some addiction and abduction

Example: carpus

Describe the pivot synovial joint

One bone rotates around the other

Example: atlantoaxial joint

Describe the ball and socket joint

Most movement

Example: pelvis

Which bones are part of the axial skeleton

Skull, ribs, hyoid bone, spinal column and sternum