Skeletal System Flashcards
What are the Functions of the Skeletal System?
- Structural support
- Protection
- Mineral storage
- Blood cell production
- Leverage
What are the 2 Types of Bone?
Compact Bone
&
Spongy Bone
What is Compact Bone?
- Dense, smooth, homogeneous appearance
- AKA cortical bone
What is Spongy Bone?
- More porous (like a sponge!)
- AKA trabecular bone
What are the 5 Shape of Bone?
- Long
- Flat
- Short
- Irregular
- (Sesamoid)
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What is the Diaphysis?
the shaft of the bone, comprised mainly of compact bone
What are the Epiphyses?
the ends of long bones, spongy bone covered by compact bone
(proximal and distal)
What is the Epiphyseal Line?
remnant of the epiphyseal plate (cartilage that turns to bone at the end of puberty)
What is Articular Cartilage?
hyaline cartilage, covers the epiphyses and decreases friction at joint articulations
What is the Medullary Cavity?
central cavity in the diaphysis
What is the Periosteum?
protective connective tissue that covers the diaphysis
What is the Endosteum?
connective tissue that lines the medullary cavity
What is the Red Bone Marrow?
mostly found in the epiphyses of long bones (adults), creates red blood cells
What is the Yellow Bone Marrow?
found in the medullary cavity, stores adipose tissue (in adults)
What is the Central (Haversian) Canal?
- Contain blood vessels and nerve supply
- Lined with endosteum
What are Perforating Canals?
- Provide channels for blood vessels in central canals to to connect with blood vessels in the periosteum
What are the Osteon (Haversian System)?
- The functional unit of bone
- Consists of lamellae and a central canal
- Found in compact bone
What is the Lacuna of the Osteon?
tiny cavity that houses osteocytes
(one osteocyte per lacuna)
What is the Lamella of the Osteon?
thin layer of matrix in concentric arrangements around Lacunae
What are Osteocytes?
bone cells
What are Canaliculi?
narrow passagewasy that extend from the lucunae into the lamallae
provide a passageway for nutrients to enter and waste products to be removed
What are the 2 Layers of the Periosteum?
What is the Function?
Fibrous outer layer
- Sharpey’s fibres
Cellular layer
- Fibroblasts, osteogenic cells
Allows for tendon and ligament attachment
What do Ligaments Connect?
Bone to Bone
Flat, Short and Irregular Bone Anatomy
Cell types in Compact vs Spongy Bone?
What are Osteogenic Cells?
AKA Osteoprogenitor Cells
- Stem cell found in bone
- Can divide into osteoblasts
What are Osteoblasts?
Premature bone cell found in the periosteum—-
- Secretes collagen
- Bone builder
What are Osteocytes?
- Mature bone cell found in lacunae
- Important for bone turnover and repair
What are Osteoclasts?
- Multinucleated
- Functions in bone resorption (the breakdown of bone matrix)
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What is Ossification/Osteogenesis?
the process of producing new bone, takes place throughout the lifespan, important post-injury and for building stronger bones (in adulthood)
What is Bone Resorption/Osteolysis?
the process of breaking down bone, important for regulating calcium and phosphate ion concentrations in the body
What is Intramembranous Ossification?
- Mesenchymal cells are used as the model framework
- Mesenchymal cells differentiate directly into bone cells
What is Endochondral Ossification?
- Formation of bone cells in place of hyaline cartilage
- Cartilage cells are used as a template (they do not become bone cells)
