Lecture 8 - Bone Flashcards
def: specialized connective tissue with calcified ECM
bone
def: dense tissue, built to withstand compression
compact bone
def: contains macroscopic open space, helps balance the strength of the bone against the weight of the skeleton
spongy/trabecular one
at the end of the head of the femur, the bone forms part of a synovial joint and the outer cortical plate consists of __________ ______ _______
articular hyaline cartilage
on the shaft of this long bone, the outer layer would be formed from ___________ ____________
fibrous periosteum
between the bony trabeculae, there are _________ ___________
intervening spaces
def: bone consists of a network of interconnecting struts orientated to provide maximum strength for the minimum mass
trabecular (cancellous bone)
trabecular bone contains ____________ ___________ ___________
haematopoietic marrow spaces
what does red marrow produce?
- red blood cells
- white blood cells
- platelets
what does yellow marrow produce?
- fat
- cartilage
- bone
____________ have only red bone marrow, _____________ marrow forms progressively with age
newborns, yellow
where is red bone marrow in adults?
primarily located in the bones of the axial skeleton, like the head of the femur
hematopoietic cells lie in intimate contact with numerous thin-walled blood vessels called _________-
sinusoids
def: wider section at each end, made from a thin layer of compact bone and filled with spongy bone, red marrow fills the spaces in spongy bone
epiphysis
def: cylindrical long portion of each long bone, with walls of compact bone
diaphysis
def: the hollow inside of the diaphysis
medullary cavity
def: dense irregular connective tissue membrane covering the other surface of most bones (except were synovial cartilage covers bone in joints)
periosteum
def: contains both collagen and elastin, as well as blood vessels and nerves
fibrous layer
def: contains both mature osteocytes and multi-potent precursors
cellular layer
what does the periosteum do?
supplies blood to bone
where are nociceptors in bone?
in the spongy bone
def: microscopic structural units of compact bone, long, cylindrical structure with a central channel called a Haversian canal, containing blood vessels, lymphatics, and nerves
osteons
def: each osteon contains concentric rings of this that forms in layers around a central Haversian canal
lamellar bone
where do osteocytes reside?
lacunae
def: prominent filopodia that extend through channels in the bone
canaliculi
what are the traversing blood vessels in compact bone called?
volkman
trabecular bone still grows in a laminar fashion, but lacks ________ and ____________ _______
osteons and Haversian canals
canaliculi from lacunae in trabecular bone open to the surface of the ________________, allowing osteocytes to communicate with highly vascular bone marrow
endosteum
def: regions between Haversian systems, remnants of older Haversian systems that have become highly mineralized
interstitial bone
def: more intense staining of osteons compared to interstitial lamellae reflects their lower mineralization
india ink
in India ink, the newest formed bone is stained how?
darker stained, it is non-mineralized, more permeable
def: connect adjacent osteons in compact lamellar bone, such canals perforate lamellae and provide another source of microvasculature for the central canals of osteons
transverse perforating (Volkmann) canals
def: maintains bone tissue
osteocyte
def: forms bone matrix
osteoblast
def: stem cells in bone
osteogenic
def: resorbs bone
osteoclasts
def: responsible for the synthesis of the organic components of bone matrix, consisting of type I collagen fibres, proteoglycans, and several glycoproteins including osteonectin
osteoblasts
where are osteoblasts located?
exclusively at the surfaces of bone matrix, usually side by side in a layer somewhat resembling a simple epithelium
active osteoblasts look like:
cuboidal to columnar shape and basophilic cytoplasm
declining osteoblasts look like:
they flatten and cytoplasmic basophilia is reduced
when bone matrix is actively proliferating, it is adding _____________
hydroxyapatite
def: remain active cells, regulating the mineral content of the bony matrix, exhibit less RER, smaller Golgi complexes, more condensed nuclear chromatin than osteoblasts
osteocytes
which has more euchromatin, an osteoblast or osteocyte?
osteoblast
osteocytes are the ________ of bone, they act as mechano-sensors to mediate load-induced adaptation and govern the activity of osteoblasts and osteoclasts
mechano-stats
def: very large, motile cells with multiple nuclei, arise from the fusion of hematopoietic progenitors in the bone marrow
osteoclasts
def: enzymatically etched depressions or crypts in the matrix in areas of bone undergoing resorption
resorption bays
def: appropriate remodelling to preserve bone health and function, is a product of the balanced activity of osteoclasts and osteoblasts
bone homeostasis
def: disease in which bone resorption outpaces bone replacement
osteoporosis
def: stone bones, mutation in osteoclasts inhibits normal bone resorption
osteopetrosis
def: brittle bone disease, multiple mutations, all affective Type I collagen production
osteogenesis imperfecta
def: osteoclasts and osteoblasts work on opposite surfaces of bone to shape the bone in one direction
bone modelling
def: osteoclasts and osteoblasts work on the same surface of bone to digest old bone and replace it with new bone
bone remodelling
