Cartilage and Bone

Question 1

what is cartilage?

Answer 1

specialized connective tissue
contains extracellular matrix enriched with
-glycosaminoglycans
-proteoglycans
these bind with collagen and elastic fibers

Question 2

types of cartilage

-what determines differences?

Answer 2

hyaline cartilage
elastic cartilage
fibrocartilage
determination
-compositional differences

Question 3

hyaline cartilage

-locations

Answer 3

epiphyseal plate
articular surfaces
walls of trachea

Question 4

elastic cartilage

-locations

Answer 4

epiglottis
cuneiform cartilage
auricle

Question 5

fibrocartilage

-locations

Answer 5

intervertebral disc
pubic symphysis
acetabular labrum

Question 6

cartilage functions

Answer 6

shock absorber
provides smooth surface for sliding area of joints
development and growth of long bones

Question 7

cartilage composition

Answer 7

cells (chondrocytes) with lacunae
extracellular matrix
-fibers
-ground substance

Question 8

matrix composition of cartilage

Answer 8

collagen
hyaluronic acid
proteoglycans
“other” glycoproteins - chondronectin

Question 9

what gives cartilage its stiffness?

Answer 9

hydrostatic bonds of the glycosaminoglycan chains of the proteoglycans

Question 10

cartilage

• vascularity
• how does it obtain nutrients

Answer 10

cartilage is avascular
nutrients supplied by diffusion through the matrix
-either by vascularization within the Perichondrium
-or by synovial fluid (for articular (hyaline) cartilage)

Question 11

what is the perichondrium

Answer 11

capsule of dense connective tissue surrounding the cartilage

Question 12

hyaline cartilage

-what type of collagen?

Answer 12

collagen type II

Question 13

perichondrium

• what type of tissue
• contains
• inner cellular layer (chondrogenic cells) becomes…

Answer 13

dense connective tissue (irregular)
contains type I collagen with fibroblasts
inner layer is adjacent to cartilage and becomes chondroblasts

Question 14

chondroblasts become ___ when enclosed in cartilage

Answer 14

chondrocytes

Question 15

chondrocytes

• appearance
• may be a number of chondrocytes in _____ due to mitotic activity

Answer 15

appearance
-elliptical at edge of developing cartilage
-round once fully enclosed in cartilage matrix
may be in lacunae

Question 16

hyaline cartilage growth is dependent upon…

Answer 16

somatomedin C from the liver

produces as a result of somatotropin from the pituitary gland

Question 17

how does growth occur in cartilage?

Answer 17

interstitial growth

appositional growth

Question 18

interstitial growth

-characteristics

Answer 18

mitotic division of chondrocytes
evident developmentally - 1st formation
growth plate - increases length of bone
articular surfaces - due to lack of perichondrium

Question 19

appositional growth

-what does it do?

Answer 19

increases girth

Question 20

elastic cartilage

• location
• types of fibers
• abundant in ____ and they are ____ than in hyaline cartilage

Answer 20

location
-outer layer of perichondrium
fiber types
-type II collagen
-elastic fibers
more abundant in chondrocytes
-larger than in hyaline

Question 21

fibrocartilage

• associated with…
• type of fibers
• perichondrium
• chondrocytes

Answer 21

associated with dense connective tissue
fibers
-collagen type I
no perichondrium
chondrocytes arranged in rows (isogenous groups)

Question 22

bone

-functions

Answer 22

structural
-support and series of levers for movement
protection of vital organs
-skull, thoracic cage, vertebral column
storage pool for Ca2+ and PO4-

Question 23

periosteum

-contains

Answer 23

outer dense connective tissue layer

inner cellular layer with osteoprogenitor cells

Question 24

central cavity of bones

-contains

Answer 24

endosteum with osteoprogenitor cells and osteoblasts

Question 25

bone matrix

Answer 25

``` glycoproteins and proteoglycans associated with collagen Type I hydroxyapatite -Ca2+ -PO4- -H2O ```

Question 26

bone cell types

Answer 26

osteoprogenitor cells osteoblasts osteocytes osteoclasts

Question 27

osteoprogenitor cells | -function

Answer 27

differentiate into osteoblasts (or chondrogenic cells)

Question 28

osteoblasts - location - function - connected via...

Answer 28

line surface of bone secrete matrix (osteoid) connected via gap junctions

Question 29

osteocytes

Answer 29

formed from osteoblasts

Question 30

osteoclasts - origin - function - type of border - what is the area of bone matrix that has been removed called?

Answer 30

``` hematopoietic in origin function -bone resorption ruffled border -irregular surface facing bone removed bone matrix -Howship's Lacunae ```

Question 31

types of bone

Answer 31

compact | spongy (trabecular)

Question 32

regions of a bone

Answer 32

``` diaphysis -shaft epiphysis -articular ends metaphsis -area of spongy bone columns between epiphyseal plate and diaphysis ```

Question 33

what separates epiphysis and diaphysis

Answer 33

epiphyseal plate

Question 34

primary vs. secondary bone

Answer 34

primary -formed embryologically (or as repair) replaced by secondary bone

Question 35

secondary bone characteristics when compared with primary bone

Answer 35

regular lamellae | more dense calcification over a more regular system of collagen fibers

Question 36

osteon - what is it? - composed of

Answer 36

deep compact bone lying between inner and outer lamellae composed of osteoblasts -these are connected via caniliculi these connected osteoblasts surround the central canal with the blood vessel -this is called a Haversion canal

Question 37

caniliculi | -function

Answer 37

connects osteoblasts in an osteon | gap junction between osteoblasts runs through here

Question 38

Haversion canals (which run parallel to the bone's longitudinal axis) are connected laterally via...

Answer 38

Volkmann's canals

Question 39

two types of bone growth

Answer 39

intramembranous | endochondral

Question 40

intramembranous bone growth | -how does it occur?

Answer 40

osteoblasts secrete matrix that begins to form spicules

Question 41

endochondral bone growth | -how does it occur?

Answer 41

hyaline cartilage model is encased by a subperiosteal bone collar (intramembranous) -this bone collar deposits bone matrix

Question 42

bone remodeling occurs as a result of...

Answer 42

growth and stresses on bone

Question 43

bone repair requires...

Answer 43

adequate blood supply | proximity of opposing bone faces

Question 44

mesenchymal cell | -what is it?

Answer 44

stem cell that has not committed to making any type of connective tissue

Question 45

primary ossification site

Answer 45

shaft of bone - ossifies first

Question 46

secondary ossification site

Answer 46

ends of bone