Human Structure and Function - Module 4

Mesenchymal cells (MSC)

An undifferentiated cell

Categories of bone based on shape

• Long bones - long diaphysis

• Short bones - Cubed shape

• Flat bones - Thin and curved

• Irregular bones - Complex in shape

• Sesamoid bones - Small and round

Diaphysis

Cylindrical shaft that runs between the two ends of a bone

Compact bone

The walls of the diaphysis

Epiphysis

The wider end section of a bone

Epiphyseal plate (Growth plate)

Where the diaphysis and epiphysis meet

Endosteum

Where bone growth, bone repair and remodelling occur

Periosteum

The thin fibrous covering the outer surface of bone

Articular cartilage

Covers the epiphysis, reducing friction and acts as a shock absorber

Articulations

Where two bones come together

Projections

Area of bone that projects above the surface of the bone

Holes

Opening or a groove in a bone

Ostoblasts

Responsible for forming new bone

Osteocyte

Primary cell of mature bone

Osteogenic cell

Undifferentiated cells with the ability to divide into osteoblasts

Osteoclast

Breaks down bone

Hematoma

Clot of blood

Internal callus

Fibro-cartilaginous matrix between the two ends of the broken bone

External Callus

Chondrocytes and Osteoblasts create a callus of hyaline cartilage and bone around outside of break

Movable joint

Allow movement

Immovable joint

Come in very close contact

Joint cavity

The space that separates the ends of two bones

Synovial membrane

Release fluid in cavity, ‘lubricating’ joints reducing friction between bones

Bursa

Reduce friction by separating the structures to prevent rubbing