Bone and Cartilage Histology Flashcards

Question

Epiphyseal line

Answer 1

Within metaphysis | Epiphyseal plate has fused

Answer 2

CT lining of all trabeculae and marrow cavity | Contains osteoprogenitor cells, reticular cells of bone marrow, CT fibers

Answer 3

Dense irregular CT covering external surface of bone Does not cover articular cartilages Neurovascular Anchored by perforating fibers embedded in matrix Contains osteoblasts

Answer 4

Arranged as trabeculae, open lattice of narrow lamellar plates Most easily seen in bones of the skull Oriented in positions that maximize strength while minimizing mass Houses bone marrow

Answer 5

Pre-existing hyaline cartilage is eroded and evaded by osteoblasts, beginning osteoid production Happens in bones of extremities, pectoral/pelvic girdles Pelvis, vertebrae, ends of clavicles

Answer 6

Osteoblasts differentiate directly from mesenchyme and begin secreting osteoid Flat bones of skull, facial bones, mandible, central part of clavicle

Answer 7

Woven bone is produced first and then replaced by lamellar bone

Answer 8

Cartilage cells undergo division and secrete collagen

Answer 9

Greatly enlarged chondrocytes | Secrete factors that initiate vascular invasion

Answer 10

Nearest the diaphysis Calcified cartilage is in direct contact with marrow cavity Blood vessels and osteoprogenitors invade the region Osteoprogenitors differentiate into osteoblasts

Answer 11

``` Autosomal dominant syndrome, mutation in FGFR3 Most common form of dwarfism Shortening of long bones Small midface Altered spinal curvature ```

Answer 12

Growth in circumference of long bones via osteoblasts in periosteum Accompanied by enlargement of marrow cavity by activity of osteoclasts in endosteum

Answer 13

Calcium deficiency in children Bone matrix does not calcify normally and the epiphyseal plate can become distorted by normal strains of body wait and muscular activity Bones grow slowly and become deformed Widening of wrist and bowing of distal radius/ulna and femur/tibia Can also be caused by failure to produce Vitamin D

Answer 14

Deficient calcification of recently formed bone and partial decalcification of already calcified matrix Vitamin D deficiency, lack of sun, GI disease Can be asymptomatic

Answer 15

Torn blood vessels release blood and produce fracture hematoma Hematoma removed by macrophages, replaced by fibrocartilage mass called pro-callus, which is then invaded by vessels and osteoblasts Fibrocartilage replaced by woven bone forming hard callus which eventually becomes compact/cancellous bone

Answer 16

Decrease in bone mass and increased fragility Loses ability to produce organic matrix (collagen) Commonly occurs in elderly and postmenopausal females

Answer 17

Lines joint cavity, except articular cartilage Vascular CT membrane Regenerative properties Absorbs shock

Answer 18

Reduces friction, avascular, no nerve supply Hyaline cartilage without perichondrium Collagen fibers run perpendicular to the tissue surface, but bend gradually to form an arc

Answer 19

Superficial- elongated and flattened chondrocytes Intermediate- round chondrocytes Deep- chondrocytes arranged in short columns Calcified- small chondrocytes surrounded by calcified matrix, borders subchondral bone

Answer 20

Separates calcified zone from subchondral bone

Answer 21

Degenerative joint disease Related to aging and injury of articular cartilage Various degrees of joint deformity and destruction Commonly affects weight bearing joints Early stage- superficial layer of articular cartilage affected Late stage- destruction of cartilage extends to the bone, where the exposed subchondral bone becomes new articular surface