BL7 - Cartilage and bone Flashcards
What are the three types of cartilage?
Hyaline
Fibrocartillage
Elastic cartillage
Name three places you can find hyaline cartilage 4
Articular cartilage of the JOINS Nose Costal margins Trachea Larynx
Where can you find elastic tissue? 3
Outer Ear
Eustachian Tube
Epiglottis
Where do you find fibrocartilage? 3
Intervertebral discs
Meniscae
Pubic synthesis
What is collagen fibres are found in hyaline?
Type II
What is collagen fibres are found in fibrocartilage?
Type I and Type II
Whats a proteoglycan how does it relate to a GAG (define)
Glycoaminoglycan binds to a protein core to form a proteoglycan. The protein glycans can aggregate to form a hyaluronic acid
Collage type I found in?
90%. Bones, tendons, skin, organs
Collage type II found in?
Cartilage
Collage type III found in?
Recticulate
Collage type IV found in?
Basal lamina
Collage type V found in?
Hair and placenta surface
What is an epiphyseal growth plate?
hyaline cartilage plate in the metaphysis at each end of a long bone.
What is an epiphyseal growth plate made of?
Hyaline cartilage (without perichondrium)
Hyaline cartilage is normally composed of three layers?
Perichondrium
Chondrocytes + ECM
Perichondrium
What type of growth occurs in hyaline cartilage?
Appositional growth. Growing from the periphery
What type of CT is the perichondrium made up of?
Dense connective tissue
What are the three parts of a long bone?
Diaphysis - middle of long bone
Metaphysis - wide part of the end of the long bone (contains growth plate)
Epiphysis - end of the long bone
In hyaline cartilage how does the cells vary.
Outer edges (perichondrium) Fibroblasts->Chondroblasts->Chondrocytes. These specialise towards the centre where they produce matrix and form lacunae (bundle together)
What does articular mean?
Joints
When hyaline ages what happens to it?
Calcifies
How does the histology of elastic cartilage structure vary from cartilage.
Same. Contains perichondrium and apposition growth
When cartilage cells group together it is called what?
Isogenous grouping. Chondrocytes
What is an entheses?
What cartilage is found here?
points of attachment of tendon and bone.
Fibrocartillage
What is endochondrial ossification?
replacement of a pre-existing hyaline cartilage template for bone
Where does endochondrial ossification occur in babies?
Long bones- Metacarpals
The femur has two growth plates found where?
Head of femur
Greater trochanter
What happens to the growth plate as it matures?
It will disappear
Draw a synovial joint.
No - go and draw it.
Endochondrial ossification. What week does it occur?
Week 14
Endochondrial ossification. What is the basic process?
Hyaline Cartilage -> Bone
Endochondrial ossification.
What type of bones
Long bones
Intramembranous ossification.
What type of bones? 3 examples?
Flat bones
Skull, Clavicle, Scapula, Pelvic bone
What is the purpose of Intramembranous ossification (Compared to appositional growth)
Thickening not lengthening
How does endochondrial ossification compare to Intramembranous ossification
EO is appositional growth which is growing bones by/in length
IO is thickening
What are the 5 stages of IO
1) Mesenchymal stem cells form a tight cluster (Nidus)
2) MSC become OSTEOPROGENITOR CELLS
3) These become Osteoblasts which lay down OSTEOID (type I collagen)
4) Osteoid mineralises and forms bone tissue and OBs become osteocytes
5) Spicules join to form trabeculae, merge and form woven bone. This then is replaced by lamellae of mature compact bone
What is the layer that surrounds bones
Periosteum
What is the layer that surrounds cartilage
Perichondrium
How is an osteoclast histologically recognisable?
Large in comparison to OB/OC
Multiple Nuclei
Which bone formation process form osteons.
Both.
The histological structure will eventually look the same from both processes
Long bones are made up of two types of bone?
Compact/Cortical
Cancellous/Spongy
Compact bones are made up of ______ (unit of bone)
Osteons
Osteon Anatomy! What is the name of the cap in the middle of an osteon?
Haversian Canal
What is the name of the outer membrane of the compact bone?
Periosteum
What is the name of the inner membrane of the compact bone?
Endosteum
Osteon Anatomy! What is the name of the “tree rings” in the osteon?
Lamellae of bone
How can you tell the difference between mature and immature bone?
Osteons, Regular order in Mature.
How does a trapped OC communicate/ get nutrients?
They have cytoplasmic processes which reach out to other OCs and HC via canaliculi
How does cancellous bone compare to that of compact?
No Haversian or Volkmann’s canals
How do osteoclasts remodel bone? 2
H+ ions and lysosomal enzymes
Fracture repair
1) Hematoma (granulation tissue)
2) Fibrocartilagenous callus formation. GT->FCC
3) Bony callus formation
4) Bone remodelling
list the most common risk factors for osteoporosis. 4
Genetic Not enough calcium intake Poor Ca absorption Reduced exercise Smoking
What is Osteoporosis?
A metabolic bone disease in which mineralized bone
is decreased in mass to the point that it no longer provides adequate mechanical support.
What is Osteoporosis? Explain in terms of osteo-cells
Osteoclasts break down the bone
Normally osteoblasts add new bone but in osteoporosis this does not occur
What are the two types of Osteoporosis
Type 1 - occurs in postmenopausal women. Increase in OClast, Oestrogen down
Type 2- Both sexes. 70+ due to reduced osteoblast function
Whats Osteomalacia?
Osteomalacia refers to a softening of your bones, often caused by a vitamin D deficiency. OM - not enough normal bone. OP - reduced density
In an intervertebral disc what are the two areas?
Inner - nucleus pulposus
Outer - annulus fibrosis (consisting of cartilage)
Which cartilage forms rows of cells?
Fibrocartilage
