Bone Histology & Structures Flashcards
what are the functions of bone?
regulate and maintain body processes
Movement via skeletal muscles
Supports and protects organs, ligaments and CTs
storage for elements and minerals
blood formation (hematopoiesis)
Sound transduction (homes of middle ear only)
what are the organic components of bone?
osteoid- organic matrix
There are fibrous and non fibrous contents. Fibrous is mostly type I collagen. It is 96% organic matter, provides scaffolding,controls the extant of mineralization, and allows for some elasticity. Non-fibrous is ground substance. It is 10% of the organic matrix that has osteoblasts secrete ground substance and contains bone matrix proteins
what are the inorganic components of bone?
alkaline phosphate removes organic material from bone matrix which results in mineralization. It allows for hardness and rigidity
What is the histology of compact/cortical bone?
The matrix of bone is lamellar. It has presence of lacunae with osteocytes. Canalaculi are present. It has dense bone tissue and is located along the surface of the bone. Cortical bone provides rigidity and stability. 80% of total adult bone mass. Osteons run parallel to long axis of the bone and contains the ostenal canal and neurovascular canal. There are Volkman’s canal as that are transverse to the ostenal calnals and are not surrounded by concentric lamellae. Within the osteon,located around the lacunae that contains osteocytes. The canaliculi containing osteocyte processes connect adjacent osteocytes to each other and major blood supply. Between osteons, remnants of previous concentric lamellae called interstitial lamellae . Following entire inner and outer circumferences of shaft of a long bone is the circumferential lamellae
What are the types of connective tissue?
Endosteum, red bone marrow, and yellow bone marrow
What are the 5 types of bone cells?
Osteoprogenitor cells, osteoblasts, osteoclasts, bone-lining cells, osteocytes
What is the function of osteoprogenitor cells?
Differentiate in osteoblasts
What is the function of osteoblasts?
Differentiate bone-forming cells and secrete bone matrix/ type I collagen and bone matrix proteins (BMP) that facilitates mineralization. Communicate with other osteoblasts and osteocytes by gap junctions
What are the functions of osteocytes?
Responsible for maintains bone matrix.
I.E. maintain Ca homeostasis, synthesize new matrix, participate in matrix degradation
What are the functions of bone lining cells?
Provides osteocytes nutritional support, regulates movement of Ca and phosphate in and out of the bone, communicates with osteocytes and other cells through gap junctions
What are the function of osteoclasts?
Helps maintain Ca homeostasis by resorbing bone due to inflammation or injury
What are the 4 stages of bone healing?
Formation of fracture hematoma
Transition of granulation tissue to soft callus
Transition from soft to hard callus
remodeling to to restore original shape and properties
What type of bone is produced in formation of fracture hematoma (1)
bone necrosis occurs at each fracture end
what type of bone is produced during the transition of granulation tissue to soft callus (2)?
granulation tissue becomes dense connective tissue. Dense connective tissue and cartilage cover fracture site which results in soft callus
what type of bone is produced during the transition from soft to hard callus? (3)
woven bone