Bone and Cartilage

Question 1

Name 4 functions of cartilage

Answer 1

structural support
cushoning
friction reduction at joints
template for growth of long bones

Question 2

What are the 3 main types of cartilage? most common?

Answer 2

hyaline, elastic, and fibrocartilage. hyaline is most common

Question 3

Where is hyaline cartilage found?

Answer 3

trachea, bronchi, larynx, ventral ends of ribs, and articulating surfaces

Question 4

hyalin cartilage is good at resisting ___________ forces and bad at resisting _________ forces

Answer 4

good- compression; bad- shear

Question 5

what are some of the common components of the ground substance GAGs?

Answer 5

hyaluronan, chondrotin sulfate, keratin sulfate

Question 6

what type of collagen is in hyaline cartilage?

Answer 6

type 2

Question 7

What is the pocket where the cells sit called in bones and cartilage?

Answer 7

lacunae

Question 8

what is different about hyaline cartilage at articulating joints?

Answer 8

no perichondrium- no blood supply or protection- little regeneration

Question 9

what type of cartilage is found in epiphyseal long plates?

Answer 9

hyaline

Question 10

how is elastic cartilage different than hyaline cartilage?

Answer 10

elastic cartilage is made of type 2 collagen with elastic fibers (elastin/fibrillin?)

Question 11

what is a distinguishing feature of elastic cartilage and why is it so?

Answer 11

its yellow d/t elastic fibers

Question 12

where are 3 places you might find elastic cartilage?

Answer 12

epiglottis, eustchian canal, auricle of the ear

Question 13

what is the principle component of fibrocartilage?

Answer 13

type 1 collagen

Question 14

fibrocartilage defends well against what type of forces?

Answer 14

shear

Question 15

fibrocartilage is often associated with….

Answer 15

dense regular CT

Question 16

name 4 places you might find fibrocartilage?

Answer 16

sternoclavicular joint
pubic symphysis
vertebrae
meniscus

Question 17

what do chondroblasts differentiate from?

Answer 17

mesenchyme

Question 18

how do the lacunae form in cartilage?

Answer 18

chondroblasts secrete ECM, so that they are surrounded by matrix and left inside a small lacuna. As they secrete more matrix, they are separated from one another

Question 19

describe an isogenous nest

Answer 19

during interstitial growth, chondrocytes divide within their lacunae, so that there are now two cells occupying it. this is impossible in bone. eventually, they are separated by the matrix they secrete.

Question 20

what is the perichondrium and what 2 things does it provide?

Answer 20

a layer of dense regular CT tissue w/ type 1 collagen bordering the collagen. it has blood vessels that provide the nutrients for the cartilage, and it has chondroblasts waiting to differentiate for appositional growth.

Question 21

when looking at lacunae, what explains the difference in color as you move away from the chondrocyte and into the matrix?

Answer 21

immature matrix is colored differently- referred to as territorial matrix. as it matures, its composition shifts. this is called interterritorial matrix.

Question 22

describe what osteoarthritis is, why it hurts, and how to help.

Answer 22

when articular cartilage is worn away, it creates bone-on-bone friction. bones are heavily innervated and so this causes pain. exercise, weight loss, and anti-inflammatories all help. RF: female, >45, obesity, previous insult

Question 23

two common glycoproteins found in bone matrix? one common one in cartilage?

Answer 23

osteonectin, osteocalin; chondronectin

Question 24

what is the purpose of calcification?

Answer 24

makes the bone less flexible

Question 25

list some functions of bones

Answer 25

``` protection support of the body generation of blood reseviour for calcium an phosphate attachment point for muscles ```

Question 26

list some types of bones

Answer 26

long, irregular, flat, short

Question 27

difference between meta, epi, and diaphysis

Answer 27

epiphysis- ends of a long bone. diaphysis is middle "shaft". metaphysis is transition period

Question 28

describe the periosteum

Answer 28

layer surrounding the bone w/ DRCT type 1 collagen, and increasingly as you move towards the bone, osteoprogenitor cells for appositional growth. this is the attachment point for muscles and ligaments

Question 29

sharpeys fingers

Answer 29

collagen extending into the bone from the periosteum that anchors it there

Question 30

endosteum

Answer 30

layer on the inside of bone. contains osteoblasts as well but primarily a site for reabsorption

Question 31

what is bone matrix called?

Answer 31

osteoid

Question 32

how do osteoclasts form and what feature does this give them?

Answer 32

fusion of macrophages/monocytes. makes them large multinucleated cells

Question 33

describe reabsorption bays

Answer 33

osteoclasts seal off a reabsorption bay so that they can release hydrolytic enzymes in a pH controlled environment. bottom edge is ruffled- folded over many times for increased surface area. Proton pumps attract many mitochondria. clear zone- lots of actin for attachment to bone.

Question 34

describe cancellous bone

Answer 34

cancellous- "spongy bone" has spicules of bone/trabeculae with areas of bone marrow. found on the epiphysis. resists compression

Question 35

describe compact bone

Answer 35

diaphysis. organized into osteons. resists bending.

Question 36

difference between lamellar and wavy bone?

Answer 36

wavy is immature. mature bone organizes itself into layers and is thus "lamellar"

Question 37

how do osteocytes communicate?

Answer 37

canaliculi

Question 38

describe an osteon

Answer 38

circumferential lamellar bone surrounding a haversian canal. osteocytes embedded in lacunae between layers. volkmann canals connect haversian canals horizontally and provide access to the periosteum and endosteum.

Question 39

describe 3 different lamellae organizations

Answer 39

outer circumferential- just under periosteum, inner circumferential- just above endosteum, interstitial- remnants of circular osteons

Question 40

Bones and cartilage are connective tissue, which means the major constituents are...

Answer 40

1. cells | 2. ECM- fibers, glycoproteins, ground substance