Anatomy and Physiology / Unit 4: The Skeletal System
4.1 Functions and Classification of Bones
Notes
The skeleton has 206 bones in an adult. Functions: support, protection, movement (levers for muscles), mineral storage (calcium and phosphate), blood cell formation (hematopoiesis in red marrow), and energy storage (fat in yellow marrow).
- By shape: long (longer than wide; femur, humerus), short (cube-shaped; carpals, tarsals), flat (thin; sternum, ribs, skull bones), irregular (vertebrae, hip bones). Sesamoid bones form in tendons (the patella).
- Bone surface markings: a foramen is a hole, a fossa a shallow depression, a process a projection, a condyle a rounded knob, a tuberosity a rough projection for attachment.
- Example: the skull bones protect the brain, so they are classified as flat bones.
Practice
Red bone marrow is the site of:
Hematopoiesis occurs in red marrow. Yellow marrow stores fat.
The patella is classified as a:
The patella develops within a tendon, so it is a sesamoid bone.
Which bone shape best describes a vertebra?
Vertebrae have complex shapes that fit none of the other categories.
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