2 - Skeletal System Flashcards
What are the major functions of the skeletal system?
- Body support
- Organ protection
- Body movement
- Mineral storage
- Blood cell production
Describe cartilage
Is avascular: cellular needs are diffused to cells
Three types: hyaline, fibrocartilage, elastic
Describe bone
Connective tissue
Bone matrix is composed of organic + inorganic material
What is the organic material that makes up the bone matrix?
Collagen + proteoglycans
- Remains in bone tissue after removal of hydroxyapatite
e. g lipid, carbohydrates, testosterone
What is the inorganic material that makes up the bone matrix?
Hydroxypaetite
e.g water, maganese dioxide, carbon dioxide, calcium
What is decalcification?
Removal of calcium
Distinguish between tendon and ligaments
Tendon: Attachment of muscle to bone
Ligament: attachment of bone to bone
What are the types of cartilage growth?
Appositional
- Cartilage added to exisiting cartilage
Interstitial
- Chondrocytes within matrix divide to add more matrix
Describe the structure of hyaline cartilage
- Collagen fibres, evenly distributed
- Chondrocytes + chondroblasts
Describe the function of hyaline cartilage
- Growth of long bones
- Allows for support and flexibility
Describe the structure of fibrocartilage
- Collagen fibres
Describe the function of fibrocartilage
- Compressible
- Tough
- Able to withstand pressure
Where can fibrocartilage be found?
- Intervertebral discs between vertebrae
Where can hyaline cartilage be found?
- Bronchi
- Rib cage
- Growing long bones
What are the main bone cell types?
- Osteoblasts
- Osteoclasts
- Osteocytes
Describe the function of osteoblasts
- Bone forming cells by: ossification
- Originate in periosteum
- Produce collagen and proteoglycans
- Hydroxyapatite is released when levels are low, stimulating mineralisation of matrix
Describe the function of osteocytes
- When osteoblast secreted enough bone matrix to become surrounded by the cell
- Inactive, only produces components needed to maintain bone matrix
- Located in lacunae
Describe the function of osteoclasts
Reabsorption, breakdown of bone to use - Ca2+ and PO4,3- for metabolic processes
- Large multi-nucleated cells
What is the role of collagen in bone tissue?
- Strength and rigidity of bone
- Without collagen, the bone would shatter
Describe a compact bone
- Consists of plates: trabeculae
- Layers of trabeculae contain BVs + bone marrow
- Trabeculae consist of lamellae with osteocytes
Describe a compact bone
- More matrix, denser – fewer pores
- Blood vessels enter bone
What is the functional unit of a long bone
Osteon/haversian system
Types of bones (classified by shape)
- Long bones
- Flat bones
- Short bones
- Irregular bones
Describe the general structure of long bone
- Diaphysis
- Articular cartilage
- Epiphysis
- Epiphyseal plate
- Periosteum
- Endosteum
Describe diaphysis
- Shaft composed of compact bone and some spongy bone
- Medullar cavity: hollow centre filled with bone marrow
Red marrow: blood cell formation
Yellow marrow: adipose tissue
Describe articular cartilage
Found on the ends
Hyaline cartilage
Describe epiphysis
- develops from centre of ossification, enlarged end of bone
Describe epiphyseal plate
- between epiphysis + diaphysis when bone grows in length
Describe peristoneum
- connective tissue membrane covering outer surface of bone
Describe endosteum
- connective tissue membrane lining inner cavities of bone
Describe epiphyseal line
- once growth stops in long bone, plate becomes ossified
