Connective TIssue

Question 1

What are characteristics of connective tissue?

Answer 1

few cells, an abundant matrix, varying amounts of protein fibers.

Question 2

What are functions of connective tissue?

Answer 2

supports other tissues, binds tissues, provides framework, creates body contours and houses special tissues.

Question 3

What are the 4 types of connective tissue?

Answer 3

elastic, reticular, loose and dense

Question 4

What are the 4 types of special tissue?

Answer 4

adipose, cartilage bone and hematopoietic

Question 5

What does loose tissue look like?

Answer 5

both collagen and elastic fibers in a loose, random fashion.

Question 6

What fibers predominate in dense tissue?

Answer 6

collagen

Question 7

What fibers predominate in reticular and elastic tissue?

Answer 7

reticular and elastic.

Question 8

Where is Wharton’s Jelly found?

Answer 8

the umbilical cord

Question 9

What is Wharton’s jelly composed of?

Answer 9

collagen, elastic fibers and ECM (e.g. glycoproteins and proteoglycans)

Question 10

Where is loose CT usually found?

Answer 10

beneath epithelial tissues of most organs and blood vessels. It contains mast cells, macrophages and capilaries.

Question 11

What are fibroblasts?

Answer 11

cells that lay down the matrix.

Question 12

Where is dense regulat CT found?

Answer 12

in tenons and ligaments. It has thicker bundles of collagen than loose CT.

Question 13

Why is dense irregular CT so irregular?

Answer 13

There is no specific orientation of collagen bundles.

Question 14

What does reticular CT contain?

Answer 14

dense irregular connective tissue with a predominance of reticular fibers. It is associated with lymphatic tissue.

Question 15

What does elastic CT contain?

Answer 15

an abundance of elastic fibers that form discontinous lamellae.

Question 16

What are the two types of dense irregular connective tissue?

Answer 16

reticular and elastic

Question 17

What is white fat?

Answer 17

unilocular; it is a single droptlet of oil that fills a cell.

Question 18

What is brown fat?

Answer 18

cells that contain numerous smaller lipid droplets. They are more abundant in newborns and are used for heating.

Question 19

What does “blast” mean?

Answer 19

a cell that is forming something; e.g. a fibroblast is a cell that forms and secretes fibers.

Question 20

What are the most common cells in the connective tissue?

Answer 20

fibrocytes and fibroblasts. They are scattered in a relatively homogenous matrix.

Question 21

What does the connective tissue matrix consist of?

Answer 21

protein fibers and ground substance; the most common are collagen fibers.

Question 22

Where is type I collagen, and what is its function?

Answer 22

general CT and bone; tensile strength.

Question 23

Where is type II collagen, and what is its function?

Answer 23

hyaline and elastic cartilage, tensile stength.

Question 24

Where is type III collagen, and what is its function?

Answer 24

parenchyma of organs and walls of blood vessels; reticular framework

Question 25

Where is type IV collagen, and what is its function?

Answer 25

basement membranes; meshwork and scaffolding

Question 26

What is the prepropeptide?

Answer 26

The peptide that is the first in collagen formation. It has a signal sequence that is cleaved in the ER of a fibroblast.

Question 27

What is procollagen?

Answer 27

The cleaved peptide sequence that is secreted into the ECM

Question 28

What ends are cleaved from the procollagen to allow polymerization?

Answer 28

The non-helical ends.

Question 29

What is the collagen molecule called once its non-helical ends hvae been cleaved?

Answer 29

tropocollagen.

Question 30

What to tropocollagen monomers form?

Answer 30

staggered arrays.

Question 31

What is ehlers-danlos syndome?

Answer 31

a syndrome caused by defects in the synthesis of collagen. It can result in hyperextension of joints, etc. and affects the strength.

Question 32

What are GAGs?

Answer 32

large, negatively charged linear polymers consisting of repeated dissarchardie units. They form most of the amorphous substances of connective tissue.

Question 33

What do GAGs form?

Answer 33

proteoglycans.

Question 34

What are the four groups of GAGs?

Answer 34

hyaluronic acid, heparin/heparin sulfate, chondroitin sulfate, kerain sulfate

Question 35

Where is hyaluronic acid found?

Answer 35

cartilage, skin, synovial fluid; essentially all connective tissues and in Wharton's jelly. It is also a lubricant in synovial fluids.

Question 36

Where is heparin/heparin sulfate found?

Answer 36

basement membrane, skin, lung, liver, blood vessels

Question 37

Where is condroitin sulfate found?

Answer 37

cartilage, bone, skin, blood vessels, heart valves, cornea; it is the most abundant of the sulfated GAGs.

Question 38

Where is keratan sulfate found?

Answer 38

type I - cornea; type II - cartilage and nucleus pulposus of intervetebral disks.

Question 39

What are proteoglycans?

Answer 39

secreted products of resident cells, such as fibroblasts, chondroblasts, etc. They stain with hematoxylin because of sulfate groups.

Question 40

What are glycoproteins?

Answer 40

proteins with one or more heterosaccharide chains containing hexosamine, galactose and other sugars. They are PAS+ and have a high protein content.

Question 41

What are examples of glycoproteins?

Answer 41

fibronectin, chondronectin and laminin

Question 42

What is fibronectin?

Answer 42

the major surface protein of fibroblasts; they occur in plasma and alpha granules of platelets. They link cells, collagen and glycosaminoglycans.

Question 43

What is chondronectin?

Answer 43

isolated from cartilage; it promotes adhesion of mature chondrocytes to collagenous substrates.

Question 44

What is laminin?

Answer 44

found in basal lamine and involved in attachment ofepithelial cells to the lamina propria. They are noncollagenous glycoprotein.