Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Block 1 > Cartilage and Bone > Flashcards

Cartilage and Bone Flashcards

1
Q

main features of cartilage

A
  • avascular, so nutrition is by diffusion
  • two types of growth
    • appositional ( from the surface)
    • interstitial (from the inside)
  • poor ability for regeneration (because avascular) and usually occurs throught the formation of fibrous scar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Perichondrium

A
  • perichondrium
    • connective tissue capsule surrounding cartilage
      • dense irregular connective tissue (Type I bundles)
      • allows passage for blood and lymphatic vessels and nerves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

chondroblasts

A

cell found close to the surface of the cartilage, derived from mesnchymal cells in the perichondrium.

actively secreting cartilage matrix

abundant RER and Golgi

responsible for appositional growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

chondrocytes

A

are chondroblasts that became embedded in the carilage matrix

large, rounded cells

occupy spaces in matrix called lacunae

produce and maintain the ECM

responsible for the interstitial growth of cartilage

dividing chondrocytes form clusters called isogenous groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Extracellular Matrix of Cartilage and its histological appearance

A
  • composed of collagen, glycosaminoglycans, proteoglycans, and multiadhesive glycoproteins
  • is highly hydrated
  • Type II collagen is the principle type of collagen found in the cartilage matrix
  • GAGs and proteoglycans make up the ground substance, specifically, hyaluronic acid, chondroitin sulfate, and keratan sulfate. (large negative charge and bind water, forming a hydrated gel)
  • multiadhesive glycoproteins cross link collagen and proteoglycans. they also attach chondrocytes to the matrix
  • histologically
    • matrix is not uniform
    • territorial matrix, that surrounds the lacunae and is rich in GAGs, stains more intensely with basic dyes (darker pink)
    • interterritorial matrix, in-between lacunae, stains less intensely with basic dyes ( light pink)
    • this is not readily observed on all slides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

hyaline cartilage

A
  • principal type of cartilage found in the body
  • well developed perichondrium
    • dense, irregular connective tissue
    • absent from articular cartilages and epiphyseal plates
  • matrix is composed of collagen type II, GAGs, and proteoglycans
  • does not contain fibers visible in light microscope
  • chondrocytes within lacunae in matrix, often isogenous groups
  • Forms
    • embryonic skeleton
    • template for bony skeleton
    • articular surface of most moveable joints
    • epiphyseal plates
    • costal cartilages
    • supports respiratory system (not epiglottis)
      • nose, trachea, bronchi, and most of larynx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

elastic cartilage

A
  • well developed perichondrium
    • similar to hyaline, but histologically will have elastic fibers
  • matrix composed of collagen type II, GAGs, proteoglycans, and elastic fibers (that can be visible by light microscope)
    • matrix of elastic cartilage does not ossify
  • chondrocytes are within large lacunae
  • found (with limited distribution)
    • ear auricle, external auditory canal walls, Eustachian tube, and epiglottis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Fibrocartilage

A
  • “hybrid” between hyaline cartilage and dense irregular connective tissue
    • limited distribution
  • does not have a perichondrium
  • matrix is composed of both collagen type II and type I (bundles, so visible to light microscope), GAGs, proteoglycans
  • found in
    • intervertebral discs
    • pubic cartilage
    • sternoclavicular and temporomandibular joints
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

bone architecture

A
  • compact or cortical bone - outer rigid shell of bone
  • spongy/trabecular/cancellous bone - forms series of spicules and trabeculae on the inner side of the compact bone that extends into the marrow cavity
  • marrow cavity - filled with reticular (hemopoetic) connective tissue or fat
  • periosteum - covering the external surface of the bone, is dense irregular
    • if covering an actively growing bone it has 2 layers
      • external fibrous layer of collagen
      • internal osteogenic layer with osteoprogenitor cells
  • endosteum - lines the internal marrow cavity and has osteoprogenitor cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

bone matrix structure

A
  • organix matrix
    • collagen type I bundles, GAGs, proteoglycans, multiadhesive glycoproteins
    • little ground substance
    • GAGs - chondroitin sulfate and keratan sulfate
    • specialized multiadhesive glycoproteins unique to bone that can bind both organic and inorganic matrix
  • inorganic matrix
    • composed mostly of calcium phosphate in the form of hydroxyapatite crystals
    • other mineral components include calcium carbonate, Mg, NA, K, etc.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

osteoprogenitor cells

A
  • found in periosteum and endosteum
  • derived from mesenchymal cells
  • can differentiate into osteoblasts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

osteoblast

A
  • principal bone-forming cell that secretes bone matrix
  • found in boundry between bone and adjacent tissue
  • secrete type I collagen and bone matrix proteins
  • responsible for calcification of the bone tissue as they lay down matrix vesicles
  • appositional growth only due to calcified matrix
  • active - cuboidal cells with basophilic cytoplasm and well developed RER and Golgi
  • inactive - turn squamous
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

osteocytes

A
  • osteoblasts that got trapped in matrix
  • housed in lacunae within the calcified bony matrix
  • canaliculi radiate out from the lacunae to connect to adjacent lacunae
    • contain the osteocyte processes and connect with other processes to create gap junctions
  • involved in the maintanence of bone and deposition and mobilization of calcium from the matrix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

osteoclasts

A
  • large, multinucleated (up to 50 nuclei) cells with acidophilic cytoplasm
  • part of the mononuclear phagocytic system
    • derived from precursor in bone marrow (unlike other bone cells derived from mesenchyme)
  • responsible for the resorption of bone
  • attaches to bone via the actin-rich area called the clear zone
  • ruffled border - the part of the cell that is in direct contact with the bone
    • contains numerous foldings
  • secretes H+ ions, collagenase, and other lysosomal enzymes into the pocket formed between teh ruffled border and the bone surface
    • promotes local digestion of collagen and dissolves the calcium phosphate crystals
  • depression in matrix etched by osteoclasts is called Howship’s lacunae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

primary/woven bone structure

A
  • is the immature type of bone laid down either when the bones are first formed or during repair
  • collagen fibers are irregular and interwoven
  • not in adults
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

secondary/llamellar bone

A
  • remodeled, mature bone
  • collagen fibers are organized into layers, or llamellae
  • is much stronger than woven bone
  • main structural unit is an osteon
17
Q

osteon/Haversian system

A
  • concentric cylindrical structure formed around a central canal which runs parallel to the long axis of the bone
  • canal is called the Haversian canal and contains neurovascular bundle surrounded by connective tissue
    • lined with osteoblasts which separate the connective tissue from the bone
  • Haversian canal is surrounded by concentrically arranged lamellae (constructed like plywood)
  • lacunae with osteocytes are located between the lamellae and connected by canaliculi
  • Volkman’s canals are transverse channels in the mature bone through which blood vessels and nerves travel from the bone periphery to the Haversian canals
    • also connect osteonal canals to one another
    • run at right angles to osteon
  • Interstitial lamellae represent the remants of old Haversian systems, which have been partially obliterated by new osteons
  • outer circumfrential lamellae are laid down by osteoblasts formed from teh periosteum on the outer side fo teh bone
  • inner circumferental lamellae are formed on the inner surface fo the bone by osteoblasts derived from the endosteum
18
Q

intermembranous ossification

A
  • bone formed directly from connective tissue
  • mesenchymal cells differentiate into osteoblasts
  • osteoblasts secrete bone matrix and form a network of spicules and trabeculae
    • initial region is called the primary ossification center
  • trapped osteoblasts become osteocytes
  • most of the flat bones of the skull are formed this way
19
Q

endochondral ossification

A
  • bone formed by replacement of a cartilaginous template with bony tissue
  • most of the long and short bones in the body are formed this way
  • phases
    • 1) minature hyaline cartilage
    • 2) cartilage model grows, serving as a structural scaffold for bone development
    • 3) a cuff of bone is formed around middle of cartilage - blood vessels invade perichondrium and becomes periosteum - bony collar formed by intermembranous ossification of the connective tissue
    • 4) because of bony collar, chondrocytes in the mid region of teh cartilage stop receiving nutrients and die, matrix becoming calcified around them and ultimately the death of teh chondrocytes in the cartilage model
    • 5) blood vessels and osteoprogenitor cells migrate in
    • 6) osteoprogenitor cells differentiate into osteoblasts which line up on the surface of calcified cartilage and start secreating bone matrix
    • 7) remodeling of newly synthesized bone and underlying calcified cartilage results in the replacement of caclified cartilage by bone matrix
      *
20
Q

epiphyseal plate and its zones

A
  • created by the secondary ossification centers located in the epiphyses of long bones
  • responsible for bone growth, absent in adults
  • can be divided into 5 zones
    • zone of reserve cartilage - consists of regular hyaline cartilage with typical chondrocytes
    • zone of proliferation - rapid tissue growth and division of chondrocytes, which form columns of stacked cells (isogenous groups), parallel to long axis of the bone
    • zone of hypertrophy - contains swollen chondrocytes, whose cytoplasm contains much glycogen. hypertrophy in chondrocytes and enlarged lacunae causes the compression of the matrix into thin septa
    • zone of calcification - chondrocytes are lost by apoptosis, accompanied by the calcification of cartilage matrix
    • zone of ossification - the appearance of bone tissue, synthesized by osteoblasts over the layer of calcified cartilage

Block 1 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions