Lab Five: The Axial Skeleton
The axial forms the long axis of the body and is made up of the skull, vertebral column, and ribcage. It
remodels itself every 4 months based on stress and weight change.
Long Bones: Humerus-Radius-Femur-Tibia
Short Bones: Carpas-Tarsals, they are roughly cubed shaped
Flat: Scapula-Ribs-Skull
Irregular: Vertebrae-Mandible
Seasmoid: Patella- shaped like a sesame seed.
Functions of Bones
1.) Support: Framework supports the body and protects organs.
2.) Protection: Skull protects the brain, vertebrae protect the spinal cord, ribcage protects lungs and
heart.
3.) Movement: Skeletal muscles which attach to bones by tendons use bones as lever to move the body
and it’s parts, Therefore we can walk, grasp, and breathe.
4.) Mineral/Growth Factor Storage: Bone is a reservoir for minerals, the most important is calcium and
phosphate. Stored minerals are released into the bloodstream as needed for distribution. Mineralized
bone matrix stores growth factors.
5.) Blood Cell Formation: Most blood cell formation (hematopoiesis) occurs in the marrow cavities of
certain bones.
Bone Markings
- Projections that are sites of muscle and ligament attachment
Name of Bone Markings Descriptions
Tuberosity Large rounded projection; Roughened
Crest Narrow ridge of bone; Prominent
Trochanter Very large, blunt, irregularly shaped process
Line Narrow ridge of bone, less prominent than crest
Tubercle Small rounded projection/process
Epicondyle Raised area on or above a condyle
Spine Sharp, slender, pointed projection
Process Any bony prominence
Projections that Help Form Joints
Name of Bone Markings Descriptions
Head Bony expansion carried on narrow neck
Facet Smooth, nearly flat articular surface
Condyle Rounded, articular projection
Ramus Armlike bar of bone
