Connective Tissue

Question 1

indigenous connective tissue cells

Answer 1

• arise within the CT
• mesenchymal stem cells
• fibroblasts
• adipocytes
• osteogenic cells and their derivatives
• chondrogenic cells and their derivatives

Question 2

mesenchymal cells

• what can they diff into? 5
• appearance

Answer 2

• multipotent stem cells that can differentiate into: myocytes, adipocytes, chondrocytes, osteoblasts, neurons
• cytoplasm extends out into long processes

Question 3

fibroblasts

• found in
• synthesize what
• staining/appearance
• differentiation

Answer 3

• most common cell in connective tissue
• synthesize most ECM components
• cytoplasm and ECm stain similarly - so you usually just see nuclei
• have capacity to differentiate into myofibroblasts (both in normal and wound healing conditions)

Question 4

white adipocytes

Answer 4

-unilocular white spot in each cell, nucleus pushed to the side

Question 5

brown adipocyte

Answer 5

-multilocular white spots in cell with distinct nucleus

Question 6

immigrant cells

Answer 6

• macrophages (derived from monocytes)
• mast cells
• lyphocytes
• plasma cells (from B lymphocytes)

Question 7

macrophage

• come from
• function
• appearance

Answer 7

• derived from blood monocytes that have wandered into connective tissue
• scavenge debris and function in both the innate and adaptive immune system and in inflammation
• irregular nucleus, large cytoplasm with phagosomes

Question 8

mast cells

• come from
• appearance
• characteristic of granules
• granule contents
• what can happen in allergic reaction

Answer 8

• derived from bone marrow precursors
• central nucleus with cytoplasm packed with granules
• granules exhibit metachromasia
• granules contain heparin (anticoagulant) and histmaine (vasodilator)
• in severe allergic reactions, body wide degranulation can lead to anaphylaxis

Question 9

lymphocytes

• reticulate
• subsets of
• appearance
• when found in connective tissues they are called

Answer 9

• reticulate (blood to CT to blood)
• subsets of B and T cells
• small dark nuclei with little cytoplasm
• “wandering lymphocyte”

Question 10

plasma cells

• what are they
• function
• found in what CT specifically
• appearance

Answer 10

• differentiated B lymphocytes
• synthesize antibodies of same specificity of parent B cells
• found in loose CT’s
• clock face heterochromatin pattern
• eccentric nucleus
• prominent, perinuclear golgi apparatus
• abundant RER

Question 11

Collagen

• made up of
• cross link between

Answer 11

-composed of fibrils
cross linked between
-hydroxylysine and hydroxyproline

Question 12

Scurvy

• cause
• symptoms

Answer 12

• a vitamin C deficiency
• this is a cofactor for the enzymes which crosslink fibrils of collagen
• causes problems with the periodontal ligament, poor wound healing, and bruising

Question 13

fibrillar collagen types to remember and their location

Answer 13

1-ubiquitous
2-cartilage
3-many organs

Question 14

type 1 collagen diseases

Answer 14

• ehlers danlos

- keloids - accumulation

Question 15

type 2 collagen

-where is it found and when

Answer 15

• abundant in hyaline cartilage
• found in many organs during development
• in the adult eye and ear

Question 16

type 3 collagen

• appearance
• found where specifically
• part of what epithelial specialization

Answer 16

• highly branched
• requires special stains to visualize
• found in many lymph organs, liver, and reticular dermis (skin)
• part of the reticular lamina

Question 17

non-fibrillar collagens

Answer 17

• represent the majority of known collagens
• basement membrane (collagen 4)
• associate with fibril collagens
• most require special techniques such as IHC to localize

Question 18

elastic fibers

• synthesis
• cross linking done by

Answer 18

• synthesis: deposition of fibrillar scaffold, addition of (tropo)elastin
• cross linking achieved with lysyl oxidase

Question 19

marfans syndrome

• cause
• symptoms
• TGF-b

Answer 19

• fibrillin-1 is mutated
• leads to aneurisms, scoliosis, hyper extensible joints
• fibrillin sequesters TGF-b and regulates its bioavailability
• excess TGF-b might lead to much of the marinas phenotype

Question 20

Cutis laxa

Answer 20

• mutation in elastin lead to skin that is loose, wrinkled and lacking elasticity
• in severe cases, internal organs could be affected

Question 21

ground substances

Answer 21

• proteoglycans
• glycosaminoglycans
• glycoproteins

Question 22

characteristics of ground substances

Answer 22

• highly charged conferring their hygroscopic nature
• charge confers compressive resistance (articulate cartilage)
• limited protein components (stains poorly)
• permits nutrient/gas exchange

Question 23

connective tissue types

Answer 23

• dense regular
• dense irregular
• loose (areolar)
• elastic
• adipose
• reticular
• cartilage
• bone

Question 24

dense regular CT

• definition
• appearence

Answer 24

• collagenouse tissue with densely packed fibers in parallel
• eosinophilic
• provides tensil strength to tendons and ligament
• fibroblasts spaced throughout

Question 25

Dense irregular CT

Answer 25

- collagen is not laid down in parallel orientation, it is wavy and moving in and out of the plane of view - fibroblasts throughout which are oriented in many different ways

Question 26

loose connective tissue

Answer 26

- appears to have large empty spaces, however this is where the ground tissue resides which is very hydrated - collagen fibers, elastic fibers, fibroblasts, mast cells, vessels

Question 27

elastic tissue | -found where

Answer 27

-found in artery (lamella) wall and dermis (branched)

Question 28

reticular tissue

Answer 28

- branched type 3 collagen - supports channels in live, lymph nodes and spleen - usually require special stains to visualize