Chapter 6 Flashcards
Diaphysis
bone shaft
Epiphyses
(2)both ends of the bone at the joints
Metaphysis
(2) region between diaphysis and epiphysis
Articular Cartilage
Covers epiphyses
Periosteum
connective tissue surronding diaphysis
Medullary cavity
hollow space within diaphysis
Endosteum
thin membrane lining the medullary cavity
Osteoprogenitor Cells
bone stem cells able to differentiate into other types of cells - developt sinto an osteoblast
Osteoblasts
bone building cell that secrete matrix - forms bone extracellular matrix
Osteocytes
Mature bone cells- maintains bone tissue
Osteoclastic
Remodel bones and cause them to release calcium- functions in resorption, the breakdown of bone extracellular matrix
Compact Bone
Good at providing protection and support
Spongy bone
lightweight and provides tissue support
Periosteal arteries
accompanied by nerves, enter the diaphysis thorugh Volkmann’s canals. They are accompanied by periosteal veins.
Nutrient artery
enters the center of the diaphysis through a nutrient foramen. Nutrient veins exit via the same canal
Ossification (osteogensis)
The proccess of bone formation. takes place during 4 situations
Ossification occurs during these 4 situations
1) embryological and fetal development
2) when bones grow before adulthood
3) when bones remodel
4) when fractures heal
two forms of ossification
intramembranous and endochondral
Intramembranous Ossification
occurs in flat bones when a connective tissue membrane (mesenchyme) is replaced by bone
Endochondral ossification
replaces cartilage with bone in the developing embryo and fetus AND in epiphyseal plates of long bones as they grown in length
Fractures heal in 3 phases/4steps
(1) reactive phase
(2) reparative phase
(3) the bone remodeling phase is the last step as the bony callus is remodeled
Reactive phase is also known as
the early inflammatory phase
reparative phase
includes formation of a fibrocartilaginous callus first and a bony callus second
the bone remodeling phase
last step as the bony callus is remodeled.
Hypocalcemia
causes excesive excitability of muscular and nervous system, leading to muscle spasm, tremors or tetany.
hypercalcemia
excessive calcum binding to cell surface makes sodium channels les likely to open, depressing muscular and nervous system
calcium-phosphate homeostaisis depends on
calcitriol,, calcitonin and PTH
Calcitriol
activated vitamin D, behaves as a hormone that raises blood calcium concentration
Parathyroid hormone PTH
secreted by the parathyroid glands found on the posterir surface of the thyroid gland. Released with hypocalcemia
