Bones, skeletal tissue and joints

Question 1

Where would you find fibrocartilage?

Answer 1

places in the body which face lots of impact

• symphysis pubis
• meniscus
• intervertebral disc

Question 2

Where would you find elastic cartilage?

Answer 2

Easiest way to remember: places that start with E

• external ears
• epiglottis
• eustachian tube

Question 3

Where would you find Hyaline cartilage?

Answer 3

Everywhere else;

• costal cartilage
• joint capsules
• thyroid, trachea, respiratory tube
• nose

Question 4

What are the two types of cartilage growth?

Answer 4

Appositional growth: growth occuring at the surface between existing cartilage and perichondrium, adds protuberance to surfaces

Interstitial growth: expands the cartilage from within; chondrocytes divide and secrete a new matrix which increases the overall size of cartilage

Question 5

Why does cartilage calcify?

Answer 5

1. At the sites where cartilage connects with bone, it is about to be replaced by bone
2. Cartilage is nutritionally/oxygen compromised

Question 6

How do chondrocytes calcify?

Answer 6

• chondrocytes hypertrophy and secrete enzymes to erode extracellular matrix
• calcium phosphate is deposited and matrix crystalizes
• chondrocytes dies and this leaves spaces

Question 7

What is the name of the mesh of bonny spines in spongy bone?

Answer 7

Trabeculae

Question 8

What are the membranes of bone?

Answer 8

Periosteum and endosteum

Question 9

What are the two layers of the periosteum and how is is secured to the bone?

Answer 9

Fibrous and Osteogenic (cellular) layer

–> connected by perforating fibers (sharpey fibers)

Question 10

What is the endosteum and where is it?

Answer 10

Endosteum is the delicate membrane on the internal surfaces of bone
–> covers the trabeculae, canals and marrow cavity

Question 11

What is the structural unit of compact bone?

Answer 11

Haversian system (osteon)

Question 12

What are the features of lamellae?

Answer 12

• weight-bearing
• column-like matrix tubes
• collagen fibers and bone salts in each layer run in the same direction, although they run perpendicular to each other in separate layers

Question 13

What is the difference between interstitial an dcircumfrential lamellae?

Answer 13

Interstitial lamellae are found between osteons

Circumferential lamellae are found deep to periosteum and line medullary cavity