Cartilage and Bone

Question 1

Cartilage originates from the ___ in week 5 and forms the fetal skeleton

Answer 1

mesenchyme

Question 2

Since cartilage is avascular, how does it get nutrition?

Answer 2

difffusion

Question 3

Cartilage has a high ability to regenerate

Answer 3

fasle; poor regeneration - fibrous scars

Question 4

These cells are found on the cartilage surface, are from mesenchyme, have a basophilic cytoplasm, and turn into chondrocytes

Answer 4

chondroblasts

Question 5

These cells are surrounded by matrix, contain lacunae, produce ECM, and have isogenous groups of interstitial growth

Answer 5

chondrocytes

Question 6

The ECM of cartilage is mostly type ___ collagen and provides ___ stability.

Answer 6

II; mechanic

Question 7

The ground substance of cartilage is poorly hydrated and has very few proteoglycans. True or false?

Answer 7

false - highly hydrated and has GAGs, proteoglycans, and multi adhesive glycoproteins

Question 8

In regards to the ECM of cartilage, the territorial regions around lacunae are ___ stained, while inter territorial regions are ____ stained

Answer 8

intensely; less

Question 9

___ cartilage is the principal type of cartilage found in the body

Answer 9

hyaline

Question 10

The matrix of hyaline cartilage is made up of what type of collagen?

Answer 10

type II

note: there are also chondroblasts and chondrocytes present here

Question 11

Where is hyaline cartilage found?

Answer 11

embryonic skeleton, most moveable joints, epiphyseal plates, costal cartilages, and the respiratory system

Question 12

Hyaline cartilage has a well-developed perichondrium composed of ___ ___ connective tissue

Answer 12

dense irregular

Question 13

This type of cartilage has a rather limited distribution and has a well-developed perichondrium

Answer 13

elastic

Question 14

The matrix of elastic cartilage is primarily composed of what?

Answer 14

collagen type II, GAGs, proteoglycans, and elastic fibers that can be visible in a light microscope

Question 15

Chondrocytes are located within large, distended ____

Answer 15

lacunae

Question 16

Where is elastic cartilage found?

Answer 16

in the ear auricle, external auditory canal walls, eustachian tube, and epiglottis

Question 17

This type of cartilage is a “hybrid” between hyaline cartilage and dense irregular connective tissue.

Answer 17

fibrocartilage

Question 18

Does fibrocartilage have a perichondrium?

Answer 18

no

Question 19

What is the matrix of fibrocartilage composed of?

Answer 19

collagen type II and type I, GAGs, and proteoglycans

note: bundles of collagen type I can be visualized in a light microscope

Question 20

Where is fibrocartilage found?

Answer 20

intervertebral disks, pubic cartilage, and sternoclavicular and temporomandibular joint

Question 21

What is the malignant proliferation of cartilage called and where is it commonly found?

Answer 21

chondrosarcoma; pelvis, proximal femur and humerus

note: slight male predominancy

Question 22

Because the ECM of bone is mineralized, the diffusion through this tissue is very limited, and bone in contrast to cartilage, is a ___ tissue

Answer 22

vascular

Question 23

The outer rigid shell of the bone is formed by ___ bone

Answer 23

compact

Question 24

____ bone forms series of spicules and trabecular on the inner side of the compact bone that extend into the marrow cavity

Answer 24

spongy

Question 25

Marrow cavity is filled with what?

Answer 25

reticular CT or fat

Question 26

In regard to bone coverings, the external surface of the bone is called the ____, and the internal surface is lined with ____

Answer 26

periosteum | note: made of dense irregular tissue; endosteum

Question 27

In regards to bone matrix, ___ matrix is similar to dense connective tissue in having large number of collagen type I bundles, GAGs, proteoglycans, and multi adhesive proteins. There is little found substance in the bone matrix

Answer 27

organic

Question 28

What is inorganic matrix composed of?

Answer 28

calcium phosphate and other mineral components

Question 29

____ cells are found in the periosteum and endosteum. They are derived from mesenchymal cells and can differentiate into osteoblasts

Answer 29

osteoprogenitor

Question 30

Osteoblasts secret type ___ collagen and bone matrix proteins and are responsible for the ____ of the bone tissue

Answer 30

I; calcification

Question 31

Active osteoblasts are ___ cells. Inactive osteoblasts are ___ cells. (cell shape)

Answer 31

cuboidal; squamous

Question 32

Osteocytes are osteoblasts that become trapped in the matrix. The are housed where?

Answer 32

in lacunae within the calcified bone matrix

Question 33

Radiating out in all directions from the lacunae are narrow, tunnel-like spaces called ____, which contain the osteocyte processes

Answer 33

canaliculi

Question 34

Osteocytes are involved in the maintenance of bone and in deposition and mobilization of ___ from the matrix

Answer 34

calcium

Question 35

Osteoclasts attach to the bone via the actin-rich area called the ___ zone

Answer 35

clear

Question 36

Malignant proliferation of osteoblasts is called _____, characterized by the production of osteoid by malignant cells and commonly occur in teenagers at the sites of the most rapid bone growth

Answer 36

osteosarcoma

Question 37

What is an osteoid osteoma?

Answer 37

a small benign tumor that occurs anywhere in the appendicular skeleton or the spine and causes acute night pains

Question 38

Describe what happens in Paget's Disease

Answer 38

increased osteoclast activity followed by rapid deposition of new woven bone which is fragile and prone to fractures

Question 39

____ bone is the immature type of bone laid down either when the bones are first formed or during repair

Answer 39

primary (woven)

Question 40

____ bone contains collagen fibers that are organized into layers, or lamellae. This bone is much stronger than woven bone.

Answer 40

secondary (lamellar)

Question 41

What is the main structural unit of lamellar bone?

Answer 41

an osteon

Question 42

A ___ is a concentric cylindrical structure formed around a Haversian canal, which runs parallel to the long axis of the bone

Answer 42

osteon

Question 43

True or false? Collagen fibers within each lamella have the same orientation, while the fibers of adjacent lamellae are at 90 degrees from each other

Answer 43

true

Question 44

Lacunae are connected by ____

Answer 44

canaliculi

Question 45

______ canals are transverse channels in the mature bone through which blood vessels and nerves travel from the bone periphery to the aversion canals

Answer 45

volkmann's

Question 46

Interstitial lamellae represent remnants of old ___ systems

Answer 46

haversian

Question 47

In ________ ossification, bone is formed directly from CT. Most of the flat bones of the skull are formed this way.

Answer 47

intramembranous

Question 48

In ______ ossification, bone is formed by replacement of a cartilaginous template with bony tissue. Most of the long and short bones of the body are formed this way

Answer 48

endochondral

Question 49

List the phases of endochondral ossification

Answer 49

1. hyaline cartilage 2. bony collar 3. cartilage hypertrophy/calcification 4. degeneration of chondrocytes 5. angiogenesis 6. migration (osteoprogenitor cells) 7. bone formation 8. removal of calcified cartilage

Question 50

In regards to the ossification of long bones, where are the primary and secondary ossification centers located?

Answer 50

primary: diaphysis of a long bone secondary: epiphyses of long bones

Question 51

``` The epiphyseal plate is responsible for bone growth and disappears in adults. It can be divided into five zones. Describe each of the following zones. reserve cartilage proliferation hypertrophy calcification ossification ```

Answer 51

reserve cartilage: hyaline cartilage and typical chondrocytes proliferation: rapid tissue growth, columns of stacked cells (isogenous groups) hypertrophy: swollen chondrocytes, causes compression of matrix calcification: chondrocytes are lost by apoptosis ossification: appearance of bone tissue