Q&A
2024
1. Identify the features of a
typical long bone.
1. Diaphysis (bone
shaft)
2. 2 epiphyses (both ends of the bone at the joints)
3. 2 metaphyses (region between diaphysis and epiphysis)
4. Articular cartilage covering both epiphyses
5. Periosteum (connective tissue surrounding the
diaphysis)
6. Medullary cavity (hollow space within diaphysis)
7. Endosteum (thin membrane lining the medulary cavity)
1. Describe the structure and function of both the periosteal and
endosteum layer of bone.
1. Periosteum: circulation and nerves, bone growth and
repair, joint capsule, ligament, tendon attachment (sharpey's
fibers)
2. Endosteum: bone growth, repair, and remodeling
1. Bone is considered connective tissue. Describe the cells, ground
substance and fibers that comprise bone.
1. Cells:
a. Osteoprogenitor cells (bone stem cells that can
diferentiate)
b. Osteoblasts (build bone by secreting matrix)
c. Osteocytes (mature bone cells)
d. Osteoclasts (remodel bone and cause them to
release calcium)
2. Extracellular Matrix: (same in compact and spongy bone)
a. Ground substance:
, i. Hydroxyapatite: calcium phosphate,
calcium hydroxide - resists compressive forces
ii. GAGs
iii. Water
b. Fibers: collagen fibers
1. Describe the lineage of osteoblasts versus osteoclasts.
1. osteoBLASTS = BUILD bone
2. osteoCLASTS = remodel/breakdown bone
1. What are the similarities and diferences between compact bone and
spongy bone? Where is each located?
1. Compact: outside, covers spongy bone
a. more protection
b. Support in single direction
c. Dense, solid - strongest form of bone tissue
d. Makes up most of the diaphysis
e. Surrounds medullary canal/marrow cavity (inside diaphysis)
f. Made of
i. Osteon (Haversian System): basic
functional unit, contains central (Haversian canal)
ii. Concentric lamellae: layers of matrix
iii. Interstitial lamellae
iv. Circumferential lamellae
2. Spongy: inside bone