connective tissue I B

Question 1

immigrant blood-derived cells are

Answer 1

white blood cells that are produced from blood cell precursors (hematopoetic cells) in bone marrow, and migrate from blood into connective tissue

Question 2

immigrant blood derived cells are important for the function of:a

Answer 2

1. immune system (defense against virus and infection)
2. tissue damage
3. allergic hypersensitivites

Question 3

lymphocytes are important for

Answer 3

acquired immunity to foregin organisms/viruses/material

Question 4

Macrophages are

Answer 4

are large “engulfing” cells that phagocytose (eat by endocytosis) cells, ECM, and other non-cellular material.

Question 5

Macrophages are critical regulatory cells that _____

Answer 5

secrete and respond to numerous extracellular signals.

Question 6

Macrophage-produced signals have numerous functions that include:

Answer 6

1. stimulation of enodothelial cells to induce blood vessel growth
2. formation (blood vessel formation=angiogenesis)
3. immune cell migration and function
4. fibroblast activation
5. blood vessel permeability

Question 7

Macrophages have several important physiological functions:

Answer 7

1. engulf (phagocytose) invading microorganisms,
2. promote blood vessel formation (angiogenesis),
3. remodel damaged tissue,
4. remodel normal developing tissue and organs as part of their morphogenesis.

Question 8

Neutrophils and eosinophils, important for ____.

Answer 8

defense against microorganisms

Question 9

Mast cells are

Answer 9

secretory cells that, when stimulated by immune responses, release various substances, including vasodilators that promote swelling in connective tissue; thus mast cells are important in edema and allergic hypersensitivities.

Question 10

Osteoclasts are ______.

Answer 10

phagocytic cells that are derived from blood monocytes and are very similar to macrophages

Question 11

Osteoclast function

Answer 11

bone resorption and remodeling, not general phagocytosis.

Question 12

precursors or differentiated blood cells must traverse the ____ to enter connective tissues.

Answer 12

endothelium of blood vessels

Question 13

Macrophages and osteoclasts derive and differentiate from _____.

Answer 13

blood monocytes

Question 14

Mast cells differentiate from ____.

Answer 14

blood basophils

Question 15

Lymphocytes, neutrophils and eosinophils come from _____

Answer 15

similar if not identical differentiated cell types in the blood

Question 16

Fibroblasts make up the components of the

_____

Answer 16

extracellular matrix of most connective tissues

Question 17

Fibroblasts are _____.

Answer 17

secretory machines that produce the fibrous proteins, proteoglycans, and other components of the extracellular matrix (the ECM)

Question 18

-Fibroblasts are capable of ____

Answer 18

cell division to produce new fibroblasts, and possibly other connective tissue types.

Question 19

The _______ of fibroblasts are highly regulated.

Answer 19

secretory activity and proliferation

Question 20

A common response to a laceration or other tissue injury is a _____

Answer 20

stimulation of proliferation of fibroblasts, and a stimulation of ECM production.

Question 21

In situations where injury is severe, scarring of tissues results from the _____

Answer 21

hypertrophy (increased growth) of fibroblast-dependent connective tissue.

Question 22

Fibroblasts are not a ____.

Answer 22

single cell type, but comprise a diverse collection of closely related cell types

Question 23

fibroblasts in different CT’s express ____.

Answer 23

different sets of markers and regulatory proteins

Question 24

The different fibroblast states are responsible for the ___

Answer 24

enormous variation in ECM structure and composition

Question 25

Fibroblasts are developmentally ____

Answer 25

flexible

Question 26

Fibroblasts can transform (differentiate) into:

Answer 26

other connective tissue cell types such as adipocytes, smooth muscle cells, chondrocytes, and osteoprogenitor cells

Question 27

Mesenchymal stem cells (MSCs) are

Answer 27

1. smaller number in adult connective tissue.
2. primary precursors for the different cell types in vivo
3. originate in bone marrow
4. produce different cell linages from hematopoietic stem cells
5. produce CT family cells

Question 28

the dominant feature of CT is that

Answer 28

most of the tissue components are extracellular.

Organized in an ECM

Question 29

ECM main components:

Answer 29

1. structural fibers which provide mechanical strength and resiliency
2. ground substance
3. lots of extracellular macromolecules embedded within or diffusing through the ECM

Question 30

ground substance

Answer 30

a hydrated gelatinous material in which structural fibers are enmeshed

Question 31

structural fibers of ECM

Answer 31

1. collagen
2. dense CT
3. Loose CT
4. elastic fibers

Question 32

most abundant structural fibers of ECM

Answer 32

collagen

Question 33

types of collagen

Answer 33

1. fibrilar collagen
2. fibril associated collagen
3. network forming collagen

Question 34

The collagens are _____ .

Answer 34

fibrous proteins of very similar primary sequence to each other; collagen proteins aggregate to form fibers of varying sizes and organizations.

Question 35

each collage molecule is composed of

Answer 35

three intertwined polypeptide chains that form a fairly rigid rope-like triple helix.

Each polypeptide is called an α chain

There are at least 25 different α chains encoded by different genes in humans.

Question 36

Assembly of these α chains in different combination leads to ____.

Answer 36

the formation of multimeric collagens of at least 17 types

Question 37

Each collagen molecule can be _____

Answer 37

aligned and cross-linked with other collagen molecules to form higher order fibrous structures.