Mcb Exam 1 - Cartilage And Bone

Front 1

Type of CT composed of chondrocytes inside lacunae of a semi-rigid ECM

Back 1

cartilage

Front 2

What stem cell do chondrocytes come from and expression of what gene causes the stem cell to differentiate into chondroblasts

Back 2

mesenchymal stem cell
SOX 9

Front 3

Fibrous CT found the surface of the cartilage. It contains the blood vessels for cartilage (which is avascular).
What 2 layers are found in this tissue

Back 3

perichondrium
Cellular layer - closest to cartilage, contains chondrogenic cells
Fiberous layer - contains fibroblasts

Front 4

What are the 3 types of cartilage and where are they found

Back 4

1) Fibrocartilage - intervertebral disks, meniscus, pubic symphasis
2) Elastic cartilage - ear, epiglottis
3) Hyaline cartilage - joint surfaces, bone template (in endochondral ossification), growth plates, airways

Front 5

What types of collagen are found in Hyaline cartilage and Fibrocartilage respectively

Back 5

Hyaline - Type II cartilage
Fibrocartilage - Type I and II

Front 6

What type of cartilage is a mix of hyaline cartilage and dense regular CT, contains no perichondrium, and is tough and resistant to forces?

Back 6

Fibrocartilage

Front 7

What are the components of Hyaline Cartilage?

Back 7

Water (makes up majority of cartilage)
Collagens (provide rigidity)
Proteoglycan aggregates (- charged to attract water)
Glycoproteins (hold chondrocytes to ECM)
Cells (make up smallest portion of cartilage)

Front 8

Describe the structure of Proteoglycan Aggregates found in Hyaline Cartilage.

Back 8

PG monomers bound to Hyaluron.

PG monomer = aggregan core protein w/ many sulfated GAGs (chondroitin & keratin)

Highly negative, making it attract water to form a shock absorbing gell

Front 9

What 2 types of cell growth are seen in hyaline cartilage and what layers is this cell growth seen in?

Back 9

1) Apposition (layer tissue on top of each other) - seen in perichondrium
2) Interstitial (growth from within tissue) - seen in chondrocytes

Front 10

A _____ is a cluster of chondrocytes all produced by one mitotic event. The darker stained area around them is the ______. The lighter area area around this matrix is the ____ and is lighter due to less concentrations of proteoglycans.

Back 10

isogenous group (cell nest)
territorial matrix
interterritorial matrix

Front 11

How is the hyaline cartilage found in articular surfaces different from the hyaline cartilage found in the rest of the body?

Back 11

contains no perichondrium
transitions to subchondral bone

Front 12

What are the organic and inorganic components of bone?

Back 12

Organic - collagen type I fibers
Inorganic - hydroxyapatite crystal (Ca and P)

Front 13

What are the 2 types of bone and where are they found in each bone?

Back 13

Compact/cortical - walls of medullary canal
Trabecular/cancellous - in epiphysis (ends of bones) and internal structure of irregular bone

Front 14

In compact/cortical bone, _____ is found on the outside of the bone, while _____ is found inside the bone and is in contact with the marrow

Back 14

periosteum
endosteum

Front 15

Which type of bone is composed of a honeycomb network surrounded by marrow, has no osteons, is covered by endosteum, and is supplied by blood vessels in the bone marrow?

Back 15

Trabecular/cancellous

Front 16

In compact/cortical bone _____ is the structural unit. A central vertical canal called the ______ contains blood vessels that supply the bone and has horizontal canals branching off called ______. Cellular processes extend through tiny cracks called _____ to reach these canals.

Back 16

osteon
Haversian canal
Volkman's Canals
canaliculi

Front 17

Describe the origin and fate of osteoblasts.

Back 17

Mesenchymal stem cell on bone surface differentiates into an osteoprogentiors that become osteoblasts.
Osteoblasts can become bone lining cells a part of periosteum, or enter bone matrix to become osteocyte

Front 18

Which type of bone cells is found in lacunae of bone matrix and fxns as a mechanosensor cell that communicates to osteoblasts and clasts via gap junctions to maintain bone matrix

Back 18

osteocytes

Front 19

How can you differentiate an osteoclasts?

Back 19

multinucleated and sit in Howship's Lacunae

Front 20

Describe the origin of osteoclasts.

Back 20

Monocytic stem cell differentiates into an osteoclast progenitor expressing RANK.
Stroma cell expressing RANKL can bind progenitor to cause osteoclasts differentiation
Or osteoblasts can make OPG to bind RANKL and prevent differentiation

Front 21

Describe the osteoclast resorption process

Back 21

1) bind bone and form ruffled border
2) cell pumps H+ to digest inorganic minerals
3) cell pumps lysosomal enzymes to digest organic matrix
4) breakdown products are transported through cell to marrow

Front 22

Describe the process of forming new "woven" (immature, disorganized) bone

Back 22

1) chondrocytes in epiphysial growth plate grow via interstitial growth in "proliferative zone"
2) chondrocytes die in "hypertrophic zone" and get matrix laid on top of them in "calcifying zone"
3) osteoclasts remove chondrocytes and trabecullar bone is made (woven bone)

Front 23

Describe how woven bone (trabecullar) is remodeled into lemellar (cortical) bone.

Back 23

Osteoblasts lay down concentric layers, or lamella, via appositional growth, creating osteonal bone.
Leftover bone from remodeling that is not apart of lamella is known as interstitial lamellae

Front 24

2/3 of the blood supply to cortical bone comes from the _____ which is supplied by the ____ blood vessel.

Back 24

endosteum
Nutrient