Wk5 L2 - Cartilage and Bone Flashcards
LO
Regarding the morphology of cartilage, bone and joints as viewed in the brightfield light microscope and the transmission electron microscope using routine staining methods:
- To describe, discuss, tabulate and draw the various components of hyaline, elastic and fibrocartilage.
- To describe, discuss, tabulate and draw the various components of bone as a tissue. Including osteoprogenitor cells, osteoblasts, osteocytes and osteoclasts.
- Outline the key cell behaviours in bone formation, modelling, growth, remodelling and repair.
Cartilage types
Hyaline
Elastic
Fribrocartilage
[heft] LM distinguish
Hyaline Cartilage
[heft]
Chondroblasts secrete ECM and rapidly divide
Can see perichondrium in trachea
* BONE PRECURSOR
* EPIPHYSEAL PLATES
* SYNOVIAL JOINT SURFACES
* END PLATES
* RESPIRATORY TRACT
Elastic cartilage
Surrounded by perichondrium
Doesn’t calcify with age
Pliant and resiliant
Located in ear and epiglottis
Fibrocartilage
No perichondrium
Chondrocytes have a round nucleus, surrounded by matrix
Fibroblasts have flat nucleus surrounded by collagen in rows
Combination of dense regular CT and Hyaline cartilage
Energy absorber and hold joints together
Bone
Lamella bone:
- Compact (Haversion & Non-Haversion)
- Trabecullar/ cencellous ( Non-Haversion)
Bone is a compound tissue:
Periosteum
Bone tissue (cells, matrix)
Endosteum
Marrow (haemopoetic, fat)
Supply
Cartilage
Matrix
Fibres collagen 90%
Other proteins 10%
Ground substance (hydroxyapatite)
Bone tissue cells
Osteoprogenitor
Bone lining
Osteoblasts
Osteoclasts
Osteocytes
Lamella bone
Compact and Spongey
Circumferential
Haversions (osteons)
Interstitial lamella (between haversions (old))
Non-Haversion
[heft]
Supply structures
Haversion canals run up haversions
Perforating canals travel horizontal between haversion canals
Endosteum Trabecula under LM
[heft]
Lacumae are where osteocytes sit
- Osteocytes are the only cells within the lamella bone itself
Canaliculi are how the osteocytes would communicate to eachother
Osteoprogenitor cells
On bone surfaces
Squamous shaped
Differentiate into osteoblasts
Osteoblasts
- Eventually give rise to osteocytes
- Differentiated bone-forming cells (from osteoprogenitor)
- Calcify the bone matrix (make it)
- Cuboidal shaped along bone surface
- Responds to mechanical stress via bone growth and remodelling
Osteocytes
- Were once osteoblasts
- Mature bone cells
- Enclosed by matrix and maintain it
- Sit inside lacunae
- communicate via canaliculi via gap junctions
Osteoclasts
- Large dome shaped cells
- Multinucleated
- Sits in hemilacunae
- Plasma membrane infoldings for SA
- Breaks down bone
Joints
Fibrous
Cartilagenous
Synovial
Synovial membrane
produces synovial fluid
mixture of cells including synoviocytes
fenestrated capillaries, sensory nerve fibres
not on articular surfaces, surrounds rest of joint space
FIBROUS JOINT UNDER LM [Canvas]
[canvas]
