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
