Pathophysiology of bone Flashcards
Hyaline cartilage (e.g. joints)
Most prevalent
High proportion collagen fibres
Provides smooth surface for joints to glide
Elastic cartilage (e.g. external ear)
More elastic fibres than hyaline
Very flexible
Fibrocartilage (e.g. Invertebrate discs spine)
Parallel rows chondrocytes and collagen fibres
Resists forces of compression and tension.
What happens to cartilage by adulthood?
Replaced by bone with full ossification by adulthood.
2 ways of cartilage growth:
Appositional growth (e.g. epiphyseal plates (ends of the bone) and articular cartilage) Interstitial growth
Appositional growth (e.g. epiphyseal plates (ends of the bone) and articular cartilage)
Miotic division of pre-existing chondrocytes in perichondrium secrete new matrix next to existing cartilage tissue (growth from the outside).
Interstitial growth
Chondrocytes within cartilage divide and secret new matrix, expanding the cartilage (growth from within)
Bone function: (4)
Structural: Support, protect and movement
Mineral storage: Calcium and Phosphate
Lipid storage
Blood cell formation: Haematopoiesis in marrow cavities if long bones
Classification of bone (4)
Long bone (e.g. Humerus, Femur) Short Bone (e.g. Carpal and Tarsal bones) Flat Bone (e.g. Sternum, skull, ribs etc.) Irregular Bone (e.g. Hip bones, vertebrae etc.)z
Long bone (e.g. Humerus, Femur) (3)
Have long shaft and two distinct ends
Classification based on shape not size
Compact bone on exterior with spongy inner bone marrow
Short Bone (e.g. Carpal and Tarsal bones) (2)
Roughly cube-like
Thin compact bone layer surrounding spongy bone mass.
Flat Bone (e.g. Sternum, skull, ribs etc.) (2)
Thin, flattened and usually curved
Parallel layer compact bone with spongy layer between
Irregular Bone (e.g. Hip bones, vertebrae etc.) (3)
Don’t fit into the previous categories
Complicated shapes
Consist of spongy bone with a thin layer of compact
Bone composition:
70% mineral: Ca2+ & PO4- as hydroxyapatite, [Ca5(PO4)3(OH)]
22% protein (95% Type I collagen + 5% proteoglycans)
8% water
Crystals of Ca2+ are deposited in and around the collagen fibres of the extracellular matrix - exceptionally hard and resist compression
Two major types of bone:
Compact Bone Cancellous Bone (spongy)
Where is Compact Bone found?
Found on the outside of the bone
Dense bone tissue on outside of bone.
Enclosed and covered by periosteum (thick fibrous membrane).
Cancellous Bone (spongy) points (4)
Interior of a bone, consisting of fibres and lamellae (reticular structure).
Metabolic Ca2+ regulation
Storage
Stem cells
Function of Cancellous bone (spongy) (3)
Metabolic Ca2+ regulation
Storage
Stem cells (for Haematopoiesis)
Where is Cancellous bone (spongy) found?
Interior of a bone
Cancellous bone (spongy) structure
Consisting of fibres and lamellae (reticular structure).
Compact bone points (3)
Dense bone tissue found on the outside of the bone
Mechanical & protective
Enclosed and covered by periosteum (thick fibrous membrane).
Compact bone structure
Enclosed and covered by periosteum (thick fibrous membrane). The structural unit called osteon
Function of compact bone
Mechanical & protective
4 parts of Long bone
Bone shaft (Diaphysis)
Epiphysis (Head of long bone)
Metaphyses, between diaphysis and epiphysis
Medullary (Marrow) Cavity