Cartilage Flashcards
What type of cells does cartilage develop from?
Mesenchyme
What is the basic cell involved in formation of cartilage?
Chondroblast
How are chondrocytes formed?
Chondroblasts secrete extracellular matrix, which surround and entraps cells. Entrapped chondroblasts called chondrocytes.
What is the space chondrocytes are kept in called?
Lacunae
Name three consituents of cartilage ground substance
Protein, glycoprotein and glycosaminoglycan (Also WATER and LIPIDS)
What type of collagen is mostly found in cartilage?
Type 2
Cartilage contains no … substances
Inorganic
What is perichondrium?
Dense irregular conective tissue which surrounds cartilage of developing bone
What are the two layes of perichindrium called?
Outer fibrous layerInner cellular layer (chondrogenic)
At what week in development does cartilage first appear?
Fifth
What is an embryo’s skeleton made up of?
Hyaline cartilage
Where is hyaline cartilage present once mostly converted to bone in embryo?
Growth plates and articular cartilage
What is appositional growth?
Growth from periphery of bone
How are new chondroblasts formed in appositional growth?
FIbroblast like cells at edge of cartilage differentiate into chondroblasts
How do chondroblasts in appositional growth create new cartilage?
Secrete extracellular matrix around them and transform into chondrocyter.
What is intersitital growth?
Chondrocytes deeper in cartilage divide and give rise to isogenous grops
What directs synthetic activity of chondrocytes?
Pressure loads, which creat electrical, mechanical and chemical signals.
Why is perchondrium not present at articular surfaces of bone?
Must be smooth
Name three types of cartilage
HyalineElastic Fibrous
Main type of collagen in hyaline
II
Main type of collagen and what constituents form the bases of fibrous cartilage?
I and II, arranged in thick bundles. Combination of dense regular connective tissue and hyaline cartilage
Four locations hyaline cartilage can be found (4)
FEARFetal skeletonEnds of long bones Anterior ends of the ribsRespiratory passages
Three locations of elastic cartilage
EEE
Ear
Epiglottis
Eustachian tube
Four locations of fibrocartilage
Intervertabral discs
Menisci
Pubic symphysis
Portions of the tendons
Function of Hyaline cartilage
Firm and flexible support
Function of elasic cartilage
Extra flexibility and support
Function of Fibrocartilage
Very strong and resistant to stretching and compressions
Periochondrium present in Hyaline?
Yes
Periochondrium present in Elastic?
Yes
Periochondrium present in Fibrocartilage?
No
How do cells in Hyaline and elastic cartilage receive nutrients?
Avascular, so rely upon diffusion
What is interesting about the extracellular matrix of elastic cartilage?
Contains collagen and many elastic fibres
What happens to Hyaline cartilage in old age and disease?
It calcifies
What happens in degenerative ageing process of Hyaline cartilage?
Calcification of matrix due to increase in size and number of chondrocytes, and due to cell death
What is osteoathiritis a result of?
Articular cartilage erosion at end of bones
What is rheumatoid arthiritis?
Occurs when secondary destruction of articular cartilage occurs by granulation of synovial membrane tissue
Does elastic cartilage ossify?
No
What is an annulus fibrosus?
Intervertabral disc capsule
What can happen to this annulus fibrosus?
Can rupture, leading to slipped disc
What is annulus fibrosus made up of?
Fibrocartilage
