Flashcards: Skeletal System Overview & Long Bone Anatomy

Q: What are the 5 main functions of the skeletal system?
A: Support, protection, movement, mineral storage, blood cell formation

Q: What are the two divisions of the skeleton and how many bones in each?
A: Axial (80 bones — skull, vertebral column, rib cage) and Appendicular (126 bones — limbs and girdles)

Q: Total number of bones in an adult skeleton?
A: 206

Q: What are the two types of bone tissue?
A: Compact bone (dense outer shell) and spongy/cancellous bone (porous, inner, honeycomb-like)

Q: What are the 5 bone shape classifications? Give an example of each.
A: Long (femur), short (carpals), flat (skull bones), irregular (vertebrae), sesamoid (patella)

Q: What is the diaphysis?
A: The long shaft of a long bone, made of thick compact bone around a hollow center

Q: What is the medullary cavity and what does it contain in adults?
A: The hollow space inside the diaphysis; contains yellow marrow (fat storage) in adults

Q: What is the epiphysis?
A: The knobby end(s) of a long bone, made mostly of spongy bone with a thin compact bone shell

Q: What is the metaphysis?
A: The region between diaphysis and epiphysis where bone growth occurs

Q: What is the epiphyseal plate and what does it become after growth stops?
A: A layer of cartilage where bones lengthen; becomes the epiphyseal line once ossified

Q: What is articular cartilage and what's a key detail about it?
A: Hyaline cartilage capping the epiphysis at joints, reducing friction/absorbing shock — it has NO periosteum covering it

Q: What is the periosteum and what does it cover?
A: A membrane covering the outside of the diaphysis (not joint surfaces); contains blood vessels, nerves, osteoblasts; anchors tendons/ligaments

Q: What is the endosteum and where is it found?
A: A thin membrane lining the inside surfaces of bone — the medullary cavity and spongy bone spaces