Quiz 2

Question 0

Territorial Matrix

Answer 0

Newly formed matrix around a chondrocyte.

Stains intensely basophilic because high concentration of sulfated glycoproteins.

Question 1

Howship’s Lacunae

Answer 1

Scooped out portions of the bone that are created by the action of an osteoclast

Question 2

Interterritorial matrix

Answer 2

less-intensely staining matrix in between lacunae of cartilage

Question 3

Isogenous Nest

Answer 3

A clone of cartilage cells from a single progenitor cells.

Question 4

What gives the cartilage its basophilic color?

Answer 4

The presence of sulfated proteoglycan.

Question 5

What is found in the extracellular matrix of hysline cartilage?

Answer 5

Some important: hyal

Question 6

What is the fiber in bones?

Answer 6

Type 1 Collagen

Question 7

What is Wolff’s Law?

Answer 7

Bone will remodel to resist forces placed on it.

Question 8

Osteoblast function

Answer 8

Produce protein context of bone matrix (including fibers) called osteids. Secrete alkaline phosphates, which in the presence of calcium, phosphate and ATP will cause precipitation (mineralization).

Question 9

Osteoclasts origin?

Answer 9

fusion of macrophage that come from circulating monocytes.

Question 10

Where does intramembranous growth occur in an adult?

Answer 10

Occurs at the periosteum especially after a injury (callous)

Question 11

What would you find in the extracellular matrix of hyaline cartilage?

Answer 11

Type II collagen fibers embedded in a ground substance comprised of sulfonated proteoglycans and glycosaminoglycans (GAGs). Some important constituents include: hyaluronic acid, chondroitin sulfate, keratan sulfate, chondroitin sulfate and heparan sulfate.

Question 12

How does fibrocartilage differ from hyaline cartilage?

Answer 12

It contains a lot of type I cartilage, along with the type II. Therefore, it appears more eosinophilic.

Question 13

Why do you have spongy bone?

Answer 13

Trabeculae of spongy bone add strength in a particular direction without adding much weight and allowing for a marrow space.

Question 14

What would you find within canaliculi in the bone?

Answer 14

The processes of osteocytes would be in the canaliculi. They contact the cytoplasmic processes of adjacent osteocytes and have gap junctions whereby they pass nutrients back and forth.

Question 15

What are the steps in intramembranous ossification?

Answer 15

Osteoblasts develop from mesenchymal osteoprogenitor cells. Cancellous bone (immature) is laid down. This bone undergoes compaction into cortical bone (immature) and remodeling then occurs with maturation of the bone.

Question 16

What are the steps in endochrondral ossification?

Answer 16

A cartilage “model” forms from mesencymal tissue. This model gwows appositionally and interstitially. A bone collar forms at the middle of the shaft, cutting this area off from nourishment and resulting in dystrophic calcification f the cartilage model. Blood vessels invade through the bone collar. These bring other cells into the model. Osteoclasts break down the calcified cartilage, forming a marrow cavity. Osteoblasts lay down bone on calcified cartilage “spicules”. Secondary ossification centers forms at the epiphyses.

Question 17

How does a bone increase in length?

Answer 17

The bone can only increase in length at the cartilage growth plate zones (epiphyseal plates). The growth in length of the bone is due to interstitial growth of cartilage (bone can not grow interstitially). There are zones of cartilage cells in the epiphyses. These include: a resting zone; a zone of proliferation; a zone of hypertrophy; a zone of calcification; and a zone of resorption. Osteoblasts will lay bone down on spicules of calcified cartilage and osteoclasts will break down calcified cartilage and the early bone in order to allow for production of mature bone.

Question 18

Which parts of the sarcomere would get shorter during muscle contraction? Which would not?

Answer 18

The I band and the H zone would get shorter; the A band would not.