histology of cartilage

Question 1

what are the two types of connective tissue

Answer 1

irregular and regular

Question 2

what are the types of irregular connective tissue

Answer 2

loose/areolar, dense irregular, adipose tissue

Question 3

desrcibe loose/ areolar connective tissue and some examples please

Answer 3

lamina propria, submucosa of the GI. this has fibres arranged in a meshwork that will facilitate movement allowing fibres to easily slide past one another

Question 4

describe dense irregular connective tissue

Answer 4

dermis, adventitia and capsules of large blood vessels. these fibres are more pattern like and are arranged in a manner to support mechanical stresses

Question 5

describe regular connective tissue and give examples

Answer 5

regular fibres arranged in manners that are in line with the stress they face, fascia, ligaments and tendons

Question 6

what two things broadly make up connective tissue

Answer 6

cells plus ECM

Question 7

what makes ECM

Answer 7

fibres plus ground substance

Question 8

resident cells of connective tissue have what origin

Answer 8

mesenchymal origin

Question 9

describe fibroblasts - like their function and appearance and that

Answer 9

spindle shaped resident cell, they adhere to fibres, produce ECM. large euchromatic nuclei with prominent nucleosomes and abundance of rER and mitochondria.

Question 10

whats the process of making collagen fibres

Answer 10

collagen starts as an alpha helix, three alpha helices come together to make procollagen. collagenase cleaves uneven ends from procollagen to make tropocollagen. many tropocollagen plus binding protein makes collagen fibrils. fibrils come together to form collagen fibres

Question 11

whats elastin made of

Answer 11

elastin is single standed elastin fibres linked by cross linking proteins.

Question 12

whats the process of making ground substance

Answer 12

GAGs plus a core protein binds to make a proteoglycan monomer. the proteoglycan monomers adhere to hyaluronan via link proteins to make proteoglycan polymers

Question 13

the negative charge of GAGs means what

Answer 13

means that the GAGs in the proteoglycan monomers repel one another - so compressive resistant. also they attract water to aid the compression resistance

Question 14

what are the three types of cartilage

Answer 14

hyaline, white fibrous and yellow elastic

Question 15

describe the chondroblasts, their role, location

Answer 15

these are mesenchymal cells which synthesise ECM. they are found as groups of 4 ish cells in a chondron, with each cell in the chondron being housed in a lacunae

Question 16

describe chondrocytes, their role and location

Answer 16

these maintain the matrix of the cartilage. they have large euchromatic nuclei with prominent nucleoli. have rER golgi and mitochondria in abundance. they secrete ECM, fibres and ground substance to a lesser extent than the chondroblasts.

Question 17

describe hyaline cartilage

Answer 17

opalescent appearance. chondrocytes are rounded and arranged in the chondrons. matrix is homogenous with lots of ground substance. has no visiblefibres and is rich in proteoglycans - hence quite water retentative so its smooth

Question 18

describe the intermediate zone

Answer 18

chondrocytes are larger and more round collagen is oblique

Question 18

describe the superficial zone

Answer 18

cells are small, elongated and run parallel to the surface. collagen is parallel with the articular surface allowing for the smooth articulation of bone at the surface

Question 19

describe articular cartilage

Answer 19

is a type of hyaline cartilage but it has no perichondrium. thickness of this type does not increase with load. it forms a smooth but deformable layer that increases the bony congruency of joints. has 3 different cell arrangements - superficial zone, intermediate zone, radial zone

Question 20

describe the radial zone

Answer 20

this has vertically arranged collagen allowing for weight bearing function and compression under weight

Question 21

describe white fibrocartilage

Answer 21

dense, white and fibrous texture. load bearing function so it resists high compressive forces. rows of chondrocytes housed in lacuna are lined between collagen. we also have fibroblasts in this collagen this produces proteoglycans and collagen but also act as stem cells

Question 22

describe yellow elastic collagen

Answer 22

fine yellow elastic fibres, cells are single or in groups. collagen and elastin also found arranged in groups.