Locomotor Flashcards
How do bones form in a foetus?
Forms first as cartilage, then blood vessels invade and bring osteogenic cells. Cartilage growth plates still remain
How do growth plates make more bone?
Cells divide in the growth plate called the prolifitive zone, they then swell with blood and osteogenic cells in the hypertrophic zone and the die off into bone
What do chondrocytes do in cartiglage
The are responsible for synthesis of the extracellular matrix.
Particularly cartiglage specific connective tissue such as collagen type II
What do Fibroblasts do in cartilage?
They are in the ECM and produce fibrous protiens in the ECM
ECM two main componants and what they do?
- Collegens - rope like protiens that resist tensile stress
- Proteoglycans - can swell resits compression stress
Hyaline Cartilage
What is it and what are the gross features
Found on the surfaces of moveable joint. Shiny and glassy in appearence.
Can withstand compressive and tensile forces as it is loadbearing but it is not elastic
Fibrocartilage
What is it and what are the gross features
Found in the intervetebral disks and the meniscus
Designed to prevent bone to bone contact and absorb shock hence can withstand compressive and tensile forces. However not designed to allow movement.
Elastic Cartilage
What is it and what are the gross features
Found in parts that need structure yet also need to be flexible e.g the auricle of the ear and the epiglottis.
Hyaline Cartilage
Histological and Cellular features
Chondrocytes are elliptical to spherical. Superficially they start elliptical paralell to the surface, as they get deeper they go to sperical the to elliptical parallel to the surface.
The chondrocytes make collagen type II and are responsible for synthesis/breakdown of all matrix componants.
Elastic Cartilage
Histological and Cellular features
Similar to hyaline cartilage except it also contains elastin which is highly reversibly deformable
Fibro Cartilage
Histological and Cellular features
Cells and collagen fibres arranged a clear structure and are found in rows. They mostly consist of fibroblasts but there also some chondrocytes.
Cells themselves are often flat and spindle shaped.
Produce collagen type I
Synovial fluid and “warming up”
Synovial fluid is the lube between hyaline cartilage in the joints.
It is viscous when immobile but when you move it increases in production and becomes less viscous. Hence why we warm up.
Responsible for providing material and removing waste from the cartilage
Form follows function
Bone can actually adapt to stress e.g. tennis player have a thicker humerus on playing side.
Cartilage can become thicker in parts that take more load
Collagen
This makes up the structure of the cartilage
Proteoglycans in cartilage - Aggrecan
This is found in cartilage and has a fixed negative charge. This attacts cations which contain water so that they can swell.
