Cartilage and Bone Flashcards
What are the components of cartilage tissue?
- Matrix containing Proteoglycan and Hyaluronic Acid
- All have chondrocytes
What are the 3 main types of cartilage?
- Hyaline
- Elastic
- Fibrocartilage
Describe the structure of Hyaline Cartilage and one location it is found
- Type II collagen matrix fibres
- Dense Tissue containing fluid
- Trachea
Describe the structure of elastic cartilage and one location it is found
- Chondrocytes and elastic fibres increasing flexibility
- Pinna of Ear, Epiglottis, Eustachian Tube
What type of collagen fibres are in Fibrocartilage and where is it found?
- Type I collagen fibres
- Intervertebral discs
What are Chondrocytes?
They lay down extracellular matrix via vesicles and lie within a lacuna
What is the difference between Appositional and Interstitial growth in Hyaline cartilage?
Appositional - Grows from periphery
Interstitial- Grows from the centre
What is the role of Hyaline cartilage in the trachea?
- Forms C-shape rings of cartilage
- Reinforces the trachea
- Lined with pseudostratified columnar epithelium
Which 3 locations are Elastic Cartilage found?
- Pinna of the Ear
- Eustachian Tube
- Epiglottis
Explain how the structure of elastic cartilage is related to its function.
Elastic fibres and lamellae make it tough but flexible
What makes up the extracellular matrix in Cartilage?
- Interweaving fibres of Proteoglycan and Hyaluronic Acid
- Combined with Ground Substance
- Stiff, gel-like and resilient
What surrounds the elastic cartilage in the Pinna layers of the Ear?
Fibrocollagenous Tissue and Adipose Tissue
What are the 2 main components of Fibrocartilage and how is it arranged?
- Chondrocytes and Fibroblasts
- Cells distributed in rows
What is Fibrocartilage a combination of?
Dense Regular Tissue and Hyaline Cartilage
What is the function of Fibrocartilage and name 2 locations it is found.
- Acts as a shock absorber and resists shearing force
- Intervertebral discs
- Knee menisci
- Pubic symphysis
What is the role of Hyaline Cartilage in foetal development?
It mineralises to form bone and grows (Endochondral Ossification)
What happens in weeks 8-12 of long bone development?
- Central cartilage calcifies
- Nutrient artery penetrates the centre forming the primary ossification centre
- Osteogenesis cells deposited
What are the three stages in postnatal long bone development?
- Medulla becomes Cancellous bone
- Cartilage forms two Epiphyseal Growth Plates
- Two Ossification Centres appear at the Epiphyses
What happens in the Pre-Pubertal stage of long bone development?
- Epiphyses ossify
- Growth plates move apart allowing growth
At what age are the growth plates replaced by bone?
Age 24+ (mature adult)
What are the proportions of Inorganic and Organic bone matrix?
65% inorganic and 35% organic
Name the 4 cells that compose bone
- Osteoprogenitor
- Osteoblast
- Osteocyte
- Osteoclast
What are Osteoprogenitor cells?
- Stem cells
- Inner layer of Endosteum and Perosteum
What are the function of Osteoblasts and Osteocytes?
- Osteoblasts are intermediate cells that lay down new bone
- Osteocytes are terminally differentiated Osteoblasts involved in tissue maintenance
What is the job of Osteoclasts?
Fused monocytes that reabsorb existing bone on the cortisol bone surface
What is the functional of Compact (Corticol) Bone?
Osteon
What traps osteoblasts in Compact Bone?
Compact mineralised collagen lamellae
Where are osteoclasts located in Compact Bone?
Osteoclasts lie on the edges of the bone
What causes Osteoarthritis?
Mechanical failure of Articular Cartilage and narrowing of the joint space
What are the symptoms of Rheumatoid Arthritis and what kind of disease is it?
- Autoimmune Disease
- Inflammation of Synovial Membrane and thickening of the Joint Capsule
- Bone and cartilage disintegrate
