Connective tissue

Question 1

Main function of connective tissue:

Answer 1

Regulation

Question 2

What do macrophages do?

Answer 2

1. Phagocytosis
2. Angiogenesis
3. Cytokine signaling

Question 3

What are the 3 classes of collagen?

Answer 3

1. Fibrilar collagen (long cables)
2. Fibril-associated collagen
3. Network Forming Collagen

Question 4

What is the role of Fibrillar collagen?

Answer 4

Collagen Type I

Rope like structures that promote tensile strength.

Question 5

What does Fibril-associated collagen do?

Answer 5

Link collagens fibers together or to other tissue components.

Question 6

What does network forming collagen do?

Answer 6

Collagen Type IV

Help make up the basal lamina.

Question 7

Where does triple helix assembly occur for collagen?

Answer 7

Intracellularly.

Question 8

Why are N-telo peptides important?

Answer 8

Their levels in Urine and blood are used to diagnose CT diseases.

Fragments also initiate formation of collagen fibrils, and catalytic bonding between collagen molecules.

Question 9

What makes elastic fibers?

Answer 9

Elastin and Fibrilin fibers.

Question 10

Marfan’s is caused by a defect in…

Answer 10

Fibrilin protein and therefore elastic fibers.

Question 11

What are 3 important properties of GAGs?

Answer 11

1. Highly - charged
2. Rigid extended structure–> gel formation
3. Activate or inactivate other proteins.

Question 12

What makes the Ground substance?

Answer 12

1. Proteoglycans
2. Other proteins and glycoproteins.
3. Solutes and H2O

Question 13

What are the 3 steps in Tissue repair?

Answer 13

1. Inflamation in blood clotting (increased perm of H2O and cells)
2. Proliferation Phase(fibroblasts activated and divide. ECM is produced)
3. Remodeling (macrophage recruitment)

Question 14

Cartilage that grows at the surface via mesenchymal stem cell growth is

Answer 14

Appositional growth.

Question 15

What do osteocytes do?

Answer 15

Modify matrix and sense it as well. They have long processes that extend through canaliculi.

They can signal for bone growth.

Question 16

What do osteoblasts secrete?

Answer 16

Osteoid and matrix vesicles.

Matrix vesicles contain Ca and PO4.

Question 17

Where do osteoclasts come from?

Answer 17

Monocytes (macrophages) in the blood that differentiate in bone marrow.

Question 18

What role do osteoclasts play in the body?

Answer 18

1. Degrade cartilage and bone matrix
2. Recruit blood vessels(angiogenesis) and other “bone cells”
3. Recruit nerves

Question 19

T/F Bone marrow can have interstitial growth.

Answer 19

False. Bone only grows at the surface via appositional growth.

Question 20

Describe the formation of a long bone:

Answer 20

Begins as a cartilage model which grows interstitially and appositionally.

Ossification begins to occur at the center of the long bone (primary ossification). This recruits nerves, blood vessels, and bone cells.

Secondary ossification occurs later at the epiphyseal growth plate.

Question 21

Where does the majority of ca mobilization occur?

Answer 21

Endosteum.

Think of all the surface area.

Question 22

Which hormone increases blood Ca levels?

Answer 22

Parathydoid

think that the calcium “va para el tyroid.”

Question 23

What 4 things stimulate bone formation?

Answer 23

1. Short range signals (such as BMPs)
2. Long Range signals (calcitonin/PTH)
3. Mechanical stress
4. Neuronal Stimulation