Structure & Type of Cartilage BSM

Question 1

Cartilage facts

Answer 1

Cartilage = a form of supportive connective tissue
Connective tissue - comes from mesenchymal cells - embryonic = mesoderm layer
Specialised Connective Tissue = Bone, cartilage and blood
Bone & Cartilage = form supportive CT
Cartilage = firm & durable - functions as a supportive structure - can cushion joints, lubricate joints & be flexible in some areas like ears
. So function = depends on the location of the particular form of cartilage

Question 2

Structural Components of Cartilage

Answer 2

Since Cartilage is also CT, therefore it will have cells, ground substance and fibres

Question 3

What are the cells which are found in cartilage

Answer 3

. Chondroblasts
. Chondrocytes
. Just like all connective tissue cells, they form from mesenchymal stem cells

Question 4

Name the fibres present in cartilage

Answer 4

. Fibres = predominantly Type 2 collagen
. Some = Type 1 collagen & elastin - depends ofcourse on the type of cartilage

Question 5

Name the ground substance found in CT

Answer 5

. Complete using byte size med video

Question 6

How many different types of cartilage are there? Name them?

Answer 6

. 3 types of cartilage
- Hyaline cartilage, elastic cartilage & fibrocartilage

Question 7

Which type of cartilage is most common?

Answer 7

Hyaline cartilage = most common + most widely distributed

Question 8

What type of cartilage forms the articular cartilage in movable joints

Answer 8

. Hyaline cartilage
. Articular cartilage = cartilage which is on the surface of bones forming joints like the elbow, knee, hip, wrist etc

Question 9

Embryonic Cartilage

Answer 9

• Is hyaline cartilage first
• Forms a temporary skeleton because it is going to get replaced with bone
• Endochondral ossification = process by which cartilage gets replaced by bone
• Ossification = how bones develop
• Mose bones develop by endochondral ossification - using a cartilaginous template thats why the term has chondral in it (chondral = cartilage)

Question 10

What does the costal cartilage do?

Answer 10

Is hyaline cartilage which attaches the ribs to the sternum

Question 11

Where in the respiratory tract can hyaline cartilage be found?

Answer 11

• Rings of the trachea

Question 12

What is the name of the process by which cartilage is formed? What are the cells present in cartilage? What are they formed from - embryonic?

Answer 12

1- Chondrogenesis
2- Chondroblasts and Chondrocytes
3 - Mesenchymal Stem Cells
Chondroblasts = synthesise ECM components & ECM = starts separating the cells. The cells divide & form little groups separated by the matrix - these cells are chondrocytes & they are located in the spaces called lacunae

Question 13

What is the difference between lacunae and lacuna?

Answer 13

. Multiple spaces = lacunae
. Single space = lacuna

Question 14

What is the PERICHONDRIUM

Answer 14

. Outermost mesenchyme forms dense connective tissue called the Perichondrium
. Perichondrium exists in all hyaline cartilage, except for the articular cartilage - articular cartilage in those movable joints does not have the perichondrium
. Perichondrium has blood supply & nerve supply
. Cartilage being well hydrated, thanks to the ground substance gets its nutrition by diffusion from the perichondrium
. Perichondrium = an outer fibrous layer & an inner cellular layer

Question 15

How many layers does the perichondrium have?

Answer 15

. 2
. Perichondrium = an outer fibrous layer & an inner cellular layer
. Inner cellular layer = chondroblasts

Question 16

What type of cartilage is predominantly in the fibres of hyaline cartilage?

Answer 16

. Type 2 collagen
. Though, the perichondrium being dense connective tissue = has more Type 1 collagen

Question 17

What is APPOSITIONAL GROWTH? How is this different to the other type of growth? And what is the other type of growth called?

Answer 17

• when the cells in the perichondrium give rise to more cartilage because the chondroblasts and perichondrium can form chondrocytes (refine definition using google)
• Interstitial growth - mitotic division of the chondrocytes, where the chondorcytes themselves just divide & the cartilage grows

Question 18

Elastic Cartilage - composition, location and characteristics

Answer 18

. Has elastic fibres in the ECM - elastic fibres make this type of cartilage more flexible & help it return to its original shape when bent
. Type 2 collagen
. Also, has a perichondrium
. Example - External Ear
E for E’s -> Elastic Cartilage in the External Ear, Epiglottis

Question 19

features of fiborcartilage

Answer 19

. Shock absrober
. Strong
. Works like a cushion
Location - Intervertebral discs: between the vertebrae of the vertrebral column, pubic symphysis and menisci of the knee joint
. Gets its strength from collagen fibres - mainly type 1 collagen
. Does not have a well-defined perichondrium