Histology of Cartilage, Bone and Joints Flashcards
What is hyaline cartilage?
the commonest cartilage in the body located in articular joints - flexible and resistant to compression
What is within the ECM of hyaline cartilage?
type II collagen, GAGs, hyaluronic acid and chondronectin (a glycoprotein which binds the elements together)
What is elastic cartilage?
hyaline cartilage with the addition of elastin
Where is elastic cartilage located?
ears, ear canal, epiglottis and larynx
What is fibrocartilage?
a mixture of dense connective tissue and hyaline type cartilage
Where is fibrocartilage located?
menisci and intervertebral discs
What type of collagen is in fibrocartilage?
type 1
What type of collagen makes up the nucleus pulposus?
type 2
How is compact bone organised?
the outermost part is in concentric layers and the inner part is organised into haversian systems (cylindrical columns)
How do osteocytes get nutrients?
via long thin processes to access blood vessels
What is yellow marrow?
mainly fat cells - most of the marrow later in life
What is red marrow?
mainly haematopoetic cells - most of the marrow early in life
What are the blood vessels in bone marrow?
sinusoids - large diameter with pores to allow entry of blood cells
What is the periosteum made up of?
an outer fibrous layer of fibroblasts, blood vessels and collagen and an inner cellular layer of osteoprogenitor cells
What are Sharpey’s fibres?
the collagen fibres of a tendon that project into the bone
What is the nerve supply of bones?
the sympathetic nervous system
What is the synovial membrane?
it is not an epithelium - it is a layer of cells made up of fibroblast like cells, macrophage like cells and connective tissue - it is responsible for making the synovial fluid
What is the synovial fluid made up of?
an ultrafiltrate of blood with added proteoglycans
What proteins do osteoblasts make?
osteocalcin, osteonectin (calcium binding proteins), adhesive proteins, proteoglycans and alkaline phosphatase
What is a measure of how much bone is being built?
alkaline phosphatase
What do inactive osteoblasts look like?
flattened cells - look like an osteoprogenitor cell
What is a marker of osteoclast activity?
tartrate resistant acid phosphatase
What happens to osteoclasts when they are not required?
they apoptose
What are the zones of the growth plate?
resting, proliferative, maturation, hypertrophic, ossification
