Flashcards in Histology of Bone an Joint Deck (51):
Hyaline cartilage is made out of
Collagen type 2
Aggrecans (chondroitin sulphate, heparan suphate)
what is connective tissue made of?
Cells + Ground Substance + Fibres
where can you find collagen type 2?
if to hyaline cartilage elastin is added we obtain?
elastic cartilage is found in?
ears, epiglottis and larynx
Fibrocartilage can be described as
mixture of dense connective tissue and isolated islands of cartilage
Fibroblasts differentiate into
in fibrocartilage the main type of collagen found is
Type 1 collagen
Fibrous Cartilage gas perichondrium T/F
where can fibrocartilage be found?
meniscus and intervertebral discs
what is the structure of a intervertebral disc?
external ring of fibrocartilage (annulus fibrosis)
nucleus pulposus (collagen type 2)
around what age does the nucleus pulpous disappears
what are the 2 pain types of bone
where are the Haversian Systems found?
in compact bone
what is a Haversian System?
Columns of bone made of lamellae (layers) around a blood vessel that run longitudinal to the bone and parallel to the lines of stress
What are the main 3 types of cells found in bone?
filling the trabecular bone one can find either
Yellow or Red bone marrow
Can yellow marrow become haematopoietic again?
yes, it preserves some cells with haematopoietic potential
Red Marrow's capillaries have ----1---- instead of capillaries
Sinusoids, to allow material leakage
Some of the bones that are important for haematopoiesis in the adult are
what is the periosteum?
layer of connective tissue that covers bone outside
(inside is the endosteum)
what can be found in the outer layer of the periosteum?
more fibrous layer, fibroblasts blood vessels and collagen
what can be found in the inner layer of the periosteum? and what is it similar to?
more cellular than the outer, osteoprogenitor cells can be found there
where in the bone there is no periosteum?
where there is the insertion of tendons and ligaments
at the site of tendon insertion to the bone the collagen fibres are continuous with those collagen fibres within the bone T/F? this is called....
blood supply to the bone occurs at 2 discrete sites these are
Epiphysis (small retinacular arteries)
Diaphysis (large artery that subdivides in the marrow)
hyaline cartilage of the articulatory surface has a perichondrium and is heavy vascularised T/F
No perichondrium, not heavily vascularised
if the cartilage is damaged it will take a long time to repair
Synovial Fluid is similar to what other substance in the body
Plasma as it also is an ultrafiltrate of plasma with the addition of proteoglycans to make it more slippery
the synovial membrane is an epithelium T/F
just a stack of cells
not many adhesion between the molecules (no intercalated discs)
what are the cells that make up the synovial membrane?
Type A Synoviocytes (Macrophages)
Type B Synoviocytes (Fibroblasts)
in the synovial membrane which layer is the main producer of fluid
the Subintimal layer (fibrous connective tissue, heavy vascularisation)
Different name for a OSTEON
what is the metabolic unit of the bone?
osteoprogenitor cells of bone can be found in
Inner layer of the periosteum and endosteum
Where are localised osteoblasts and what is their function?
on the surface of the bone
lay down matrix that will become bone (OSTEOID)
main type of collagen found in bone?
Type 1 Collagen
Where are osteocytes found? function?
within the lamellae of bone in the Haversian System
--> Maintain bone healthy (has little processes that connect one with another and ultimately with a blood vessel). Can reabsorb bone to release Ca+2 if needed
osteoclast characteristics? function
Giant, multinucleate cells that DESTROY bone
creates a little pit underneath it, and seals itself around it, releasing acid products and enzymes (proteases and phosphatases) for the breakdown of bone
what can be measured in plasma in order to ascertain osteoclast activity?
Tartrate Resistant Acid Phosphatase
what is the main driver for increased osteoclast activity?
cell lineage osteoclasts come from?
monocyte/macrophage lineage from the bone marrow
During foetal development what are the 2 main types of bone laid down?
What is the process of membrane bone formation? what are some examples?
bone directly deposited into embryonic tissue from the mesenchyme
skull, mandible, flat bones of face and clavicles
All weight baring bone and extremity bones are of which formation type?
Endochondral Bone formation requires transforming cartilage into bone T/F
Not making bone out of cartilage but rather destroying cartilage whilst making bone using the cartilage as a mould
Describe the formation of bone from the cartilage mould
Bone collar forms around diaphysis
■ The cartilage beneath the ollar degenerates
■ Blood vessels invade, bring in bone cell progenitors
■ A second nucleus of ossification appears in each epiphysis
■ Zones of ossification grow together, but leave a thin zone of cartilage, the growth plate
when'd does the growth plate disappears?
~ 21-22 y
what are the layers of the growth plate?
during development or after injury (during repair) a specific kind of bone is produced what is its name? what are its characteristics?
more cellular, more collagen No Haversian Systems (little ossification, not very strong)
Remodelling of bone occurs down the lines of ---1--- of the bone
Lines of Stress