Bone anatomy and development Flashcards
what are the four basic types of bones? (make examples)
short, flat, irregular, and long bones
where are the periosteum and endosteum located?
periosteum = is found on the outer surface of bone endosteum = lines the medullary cavity
what types of cells are found in the periosteum and endosteum?
osteoblasts, osteoclasts, osteochondral progenitor cells
what is the function of perforating (sharpey) fibers?
used to attach muscle to the periosteum of bone by merging with the fibrous periosteum and underlying bone as well.
where is red and yellow bone marrow located in a child and an adult?
in children = medullary cavity is red marrow
in adult = red marrow is replaced by yellow in limb bones; elsewhere varying portions of yellow/red marrow are found
compare the structure of a long bone with those of flat, short, and irregular bones. Explain where compact and spongy bones are found in each type
Flat bones = interior framework of spongy bone sandwich between 2 layers of compact bone
short bones = no diaphyses and not elongated
irregular bones = compact bone surrounds spongy bone center; similar to structure of epiphysis of long bones
diaphysis
shaft; primarily compact bone
epiphysis
end of the bone; primarily spongy bone
periosteum
outer, double-layered connective tissue membrane with ligaments and tendons attached to bone through the periosteum; blood vessels and nerve pathways; the periosteum is where one grows in diameter
endosteum
thin connective tissue membrane lining the inner cavities of bone
articular cartilage
thin layer of hyaline cartilage covering a bone where is forms a joint (articulation) with another bone
epiphyseal plate
growth plate; hyaline cartilage; present until growth stops
spongy bone
bone having many small spaces; found in epiphysis; arranged into trabeculae
compact bone
dense bone with few internal spaces organized into osteons; forms the diaphysis and covers the spongy bone of the epiphysis
medullary cavity
large cavity within the diaphysis
red marrow
connective tissue in the spaces of spongy bone or in the medullary cavity; the site of blood cell production
yellow marrow
fat stored within the medullary cavity or in the spaces of spongy bone
describe the formation of spongy and compact bone during intramembranous ossification
spongy bone = osteoblasts come together on the trabeculae and produces bone, which causes the trabeculae to become bigger and longer; spongy bone forms as trabeculae join which allows interconnected network of trabeculae separated by spaces
compact bone = osteoblasts from the periosteum lay down bone matrix to form an outer surface of compact bone
what are centers of ossification?
the locations in the membrane where ossification begins
what are fontanels?
soft spots; larger membrane covered spaces between the developing skull bones that have not yet ossified; usually close at the age of 2
describe the process of endochondral ossification
chondroblasts make a cartilage model surround by perichondrium (except where joints will form) –> perichondrium becomes the periosteum and bone collar is produced; chondrocytes, hypertrophy, calcified cartilage forms –> primary ossification center forms; blood vessels and osteoblasts invade calcified calcium; osteoblasts lay down bone matrix forming spongy bone. –> secondary ossification form in the epiphyses of long bones –> in mature bone, epiphyseal plate becomes a line and all cartilage becomes bone (except articular cartilage)
when do primary and secondary ossification centers appear during endochondral ossification?
Primary ossification center = forms in the diaphyseal region of the periosteum called the periosteal collar. Secondary ossification centers = develop in the epiphyseal region after birth.
epiphyseal line
bone stops growing in length
perichondrium
CT covering over cartilage, except at articulations
periosteum
CT membrane cover outer surface of bone
osteocyte
maintain matrix
osteoclasts
break down matrix for reabsorption
intramembranous ossification
flat bones - ribs, scapula, pelvis, skull; takes place in CT membrane
endochondral ossification
most bones in the body-long bones; takes place in cartilage
