Bone & Soft Tissue Flashcards
What there components comprise the musculoskeletal system?
Bone
Muscle
Connective tissue
Give three examples of connective tissue in the msk system?
Tendon
Ligaments
Cartilage
What are tendons?
Connects muscle to bone
What are ligaments?
Connects bone to bone
What is cartilage?
Structure support
Protects tissues
Attachment sites
How is the Skeleton divided into two anatomical regions?
Appendicular and axial
What does the appendicular skeleton contain?
Pectoral girdle, upper and lower limbs, and pelvic girdle
What anatomical structures does the axial skeleton contain?
Cranium, vertebral column, and rib cage
What are the five functions of the skeletal system?
Movement Support Protection Site of calcium storage Site of haemopoesis
Which cells do osteogenic stem cells derive from?
Derive from mesenchymal stem cells
Which cells do osteogenic stems differentiate into?
Osteoblasts and chondroblasts
What is the function of osteocytes?
Capable of bone deposition and resorption, involved in bone remodelling by transmitting signals to other osteocytes in response to slight bone deformations caused by muscular activity, strengthens bone due to additional stresses.
Mature osteoblasts, that have been enveloped by the bone matrix, osteocytes continue to form bone to an extent (maintains strength of bone matrix).
Where do osteocytes reside within the bone?
Reside within the lacuna off the bone
How do osteocytes communicate with other cells?
Through surrounding canaliculi
What is a lacuna?
Calcified matrix of bone
What are canaliculi
Cytoplasmic processes of the osteocyte extend distally from the cell towards other osteocytes.
What is the function of canaliculi?
Exchange of waste productions and nutrients exchanged to maintain the viability of the osteocyte.
What is the main function of osteoblasts?
Responsible for synthesis and catalyses mineralisation of osteoids during bone formation and remodelling.
Arise from differentiation of osteogenic cells in the periosteum,.
What enzymes are released by osteoblasts?
Alkaline phosphatase
Collagenase
Which factors are released by osteoblasts?
growth factors
hormones
collagen
Which hormone is released from osteoblasts?
Osteocalcin
What types of cells are osteoclasts?
Large multinucleate cells responsible for the dissolution and absorption of bone
What function is performed by osteoclasts?
Bone resorption, dissolution and absorption of bone ; mediators of one destruction, resorb bone by phagocytosis
Where do osteoclasts reside?
Reside within the minor depression indented on the bone surface, referred as Howship lacunae
What is formed by osteoclasts during osteclastogenesis?
Ruffled border
What is a ruffled border?
Invaginations of the plasma membrane, defines the active region, whereby phosphatase enzymes are secreted to dissolve the organic collagen,
Which organic component of bone is resorbed by osteoclasts?
Organic collagen (Type 1)
Which inorganic component of bone is resorbed?
Inorganic calcium and phosphate
Which proteins form the sealing zone between the osteoclast and bone?
Sialoprotein
Osteopontin
Which inorganic compound is removed bone?
Calcium hydroxyapatite are removed from the bone by acidification
Which part of bone is protected against osteoclastic resorption?
Osteoid
Where are osteocytes located?
Matrix lacunae
Where are osteogenic cells located?
Deep layers of periosteum
Where are osteoblasts located?
Growing portions of bone, including periosteum and endosperm
What are the three components of ground substance?
Proteoglycans
Glycoproteins
Cytokine and growth factors
What are the 2 inorganic components?
Calcium hydroxyapatite
Osteocalcium phospahte
What are the two main bone type?
Immature woven bone
Mature bone
What are the two types of mature bone?
Cancellous bone
Cortical bone
How is mature bone arranged?
mineralised woven bone with a lamellar structure
How is cortical bon arranged?
Densely arranged osteons (Haversian systems)
Osteon consists of central canal, surrounded by concentric rings (laemallea) of the matrix.
Intermediate of the matrix rings are osteocytes, locate in lacunae. Canaliculi (contains extracellular fluid) radiate from lacunae to the Haversian canal to provide passageways through the hard matrix
What does one osteon contain?
Central canal
How are osteons arranged?
Concentric rings of matrix,
What are the purposes of canaliucli in cortical bones?
Contains extraceluar fluid radiate from the lacunae to the Haversian canal to provide passageways through the hard matrix
What doe osteonic canals?
Encapsulates vasculature that are parallel to long axis of the bone
How are osteonic canals linked?
Perforating canals with vessels on the surface of bone- Volkmann’s canal
What are cortical bones?
Supports body weight, protects organs, provide levers for movement, store and release calcium
What is the structure of cancellous bone?
Trabecular
Where does cancellous bone predominant?
Predominates epiphysis of bones , and within the medullary canal
What are the distinctive comparisons between cancellous and cortical bone?
Higher surface area, less dense, softer, weaker and less stiff
What do the irregular cavities contain within cancellous bone?
Red bone marrow
Where is the site of haemopoesis within cancellous bone?
Red bone marrow within cancellous bone
How are adjacencies cavities of cancellous bone connected?
Canaliculi
How does the structure of trabecular change upon addition stress?
Realign in accordance to stress directions, resistant to mechanical stress
What are the functions of cancellous bone?
Greater surface area, ideal for metabolic cavity; change of calcium ions. Cancellous bone is highly vascular and bone marrow is site of haemopoiesis.
What two structures divide long bones?
Diaphysis
Epiphysis
What is the diaphysis?
Tubular shaft that traverses between the proximal and distal ends of the bone.
What is considered in the hollow region within cancellous bone?
medulla cavity, encapsulates yellow marrow
What types bone is located diaphysis?
Compact dense bone
What is the point whereby the diaphysis meets the epiphysis?
Metaphysis
Within the epiphyseal line, which region is responsible for growth?
Epiphyseal plates
What type of cartilage is located within the epiphyseal plates?
Hyaline cartilage
How does the epiphyseal line form?
Hyaline cartilage is replaced by osseous tissue, and the plate becomes the line.
What is the membranous lining of the medially cavity?
Endosteum
What is the function of endosteum?
Bone growth , repair, and remodelling occurs.
What is outer surface of medulla cavity?
Periosteum