Connective Tissue

Question 0

Type 2 Collagen

Answer 0

Small Banded Fiber
Distribution: Hyaline and Elastic Cartilage, Eye
Fxn: Resists Pressure

Question 1

Collagen Type 1

Answer 1

Large Banded collagen fiber
In: General CT, Tendon, Bones, Ligaments, Organ (capsules)
Function:Resists Tension

Question 2

Type 3 Collagen

Answer 2

Small Banded Reticular Collagen
In: Lymph, Spleen, Liver, lung, cardiovascular, skin, bone marrow
Structural Framework

Question 3

Type 4 Collagen

Answer 3

Sheet Like Layers

• Basement membrane, Basal Lamina
• Support/Filtration

Question 4

Type 5 Collagen

Answer 4

Thin Fibrils

• Dermis, Tenson, Bone ligaments, capsules of organs, placenta
• With type 1
• placental ground substance

Question 5

Type 7 Collagen

Answer 5

Thin Fibrils

• junction of dermis and epidermis
• anchoring fibrils in basement membrane

Question 6

What are the 5 kinds fo connective tissue proper?

Answer 6

Loose (areolar)
Dense irregular
Dense regular
Reticular
Adipose

Question 7

Where is dense regular connective tissues

Answer 7

Tendons, ligaments

Question 8

Where is dense irregular connective tissue

Answer 8

Dermis of skin, nerve sheaths, spleen capsules, kidney, lymph nodes, testes, ovaries
-glands, GI tract, blood vessels (filling spaces just deep to skin)

Question 9

Glycosaminoglycans

Answer 9

GAGs

• polysaccharides of repeating dissacharides
• Sulfated-gives the name (ex. Chrondroitin)
  
  • also gives it a negative charge which attracts Na+ and water to help resist compression
• The protein attaching them is Hyaluronic Acid

Question 10

What is the protein in unsulfated GAGs

Answer 10

Hyaluronic Acid

Question 11

What are proteoglycans?

Answer 11

Protein Core with covalently bound sulfated GAGs

-important for binding and activation of growth factors

Question 12

Glycoproteins

Answer 12

Ex: Fibronetin, lamin, enactin

FHave domains that bind components of ECM and integrins (found in basement membrane)

Question 13

What is the general structure of a collagen Fiber

Answer 13

Made of many collagen fibrils. Firbil made of tropocollagen triple helix of alpha chains.
-Have overlapping regions and gap regions so it looks like dark/light pattern

Question 14

What are the common amino acids in collagen

Answer 14

Every 3r amino acid is glycine

Other common ones: proline, hydroxyproline, hydroxylysine

Question 15

Where is collagen made? What are the three steps

Answer 15

• Translated to preprocollagen in RER
• Hydroxylated/Glycosylated in RER and procollagen made and secreted by Golgi
• Outside of the cell procollagen peptidase cleaves to tropocollagen and spontaneous self assembly to make fibril

Question 16

Are reticular fibers thin or thick

Answer 16

thin 0.5-2micrometers

Question 17

Where are reticular fibers

Answer 17

soft tissues in lymph, liver, bone marrow, spleen

-provide the “scaffold”

Question 18

What do you use to stain reticular fibers

Answer 18

Dont stain well with H&E, but they are pretty glycosylated so stain well with silver and PAS

Question 19

Are elastic fibers thin

Answer 19

yes, much thinner than surrounding collagen in slides

Question 20

What are elastic fiber cells made of

Answer 20

Elastin Core and fibrillin microfibrils.

Question 21

Where are elastic fibers found? are they in regular and irregular ct?

Answer 21

Larynx, Muscular Artery

yes

Question 22

Scurvy

Answer 22

Vitamin C deficiency. Vitamin C is a ofactor for proline hydroxylase

Question 23

Ehlers Danlos

Answer 23

Collagen or enzyme related to collagen mutation. super felxible joints, succeptible to GI tear

Question 24

Marfan

Answer 24

defect in fibrillin gene

Question 25

Is fibroblast a fixed or wandering cell

Answer 25

fixed

Question 26

What is the principal cell of ct? Where are they derived from

Answer 26

Fibroblasts. Mesenchymal cells

Question 27

What do synthetically active fibroblasts do

Answer 27

produce procollagen, and ECM components -look spindle shaped, and contain well developed RER and Gogli (dormant ones look very different with mostly heterchromatin)

Question 28

Myofibroblasts

Answer 28

Have more actin and look like smooth muscle--help in wound closure and healing

Question 29

What are pericytes

Answer 29

Undifferentiated mesenchymal cells associated with capillaries and small veules - smaller than fibroblasts - have characteristics of smooth muscle and endothelial cells

Question 30

What are the two type of adipocytes

Answer 30

Unilocular and Multilocular

Question 31

What do unilocular cells look like

Answer 31

A single large lipid droplet. it gets washed out in H&e stain

Question 32

What are the functions of unilocular adipocytes

Answer 32

White/yellow fat 1. Stored lipid (triglycerides)-made in adipocytes or liver 2. Mobilization of lipids (under hormonal control) 3. Produce Leptin (decreases food intake, increases E consumption)

Question 33

What kind of fat do you find multilocular adipocytes

Answer 33

- Brown fat. (it is brown because it has cytochromes in the mitochondria) - 2-5% of newborn body weight.

Question 34

What is the fxn of brown fat? What special protein does it contain in the mitochondria

Answer 34

Production of heat controlled by smpathetic innervation. | Mitochondria have thermogenin which allows back flow of H+ ions across inner membrane.

Question 35

What is hypertrophic Obesity

Answer 35

Adult onset, increase in cell size

Question 36

What is hypercellular obesity

Answer 36

Childhood onset, increase in cell number

Question 37

What is the main phagocytic cell of the CT

Answer 37

histiocyte/macrophage

Question 38

Where do histiocytes originate? as what?

Answer 38

Bone marrow as monocytes. -part of mononuclear phagocye system

Question 39

What happens when macrophages fuse

Answer 39

they form foreign body giant cels that surround an phagocytose large foreign bodies.

Question 40

Where are the parts of the mononuclear phagocyte system made

Answer 40

monocytes

Question 41

Are plasma cells transient or fixed

Answer 41

Transient

Question 42

Where do plasma cells originiate

Answer 42

B lymphocytes.

Question 43

What is the typical appearance of a plasma cell nucleus

Answer 43

Cartwheel nucleaus.

Question 44

Where are plasma cells found? what is there fxn

Answer 44

abundant at sites of chronic inflammation | make/secrete immunoglobins

Question 45

Where do mast cells originate

Answer 45

Bone marrow

Question 46

How big are mast cells

Answer 46

very big 20-30 um

Question 47

What is the function of mast cells

Answer 47

inflammatory reponse. The basophilic granules have primary mediators (heparin, histamine, eosinophil, chemotatic factors..) secondary mediators as well (leukotrienes, thromboxins, prostglandins) -anaphylaxis

Question 48

How are mast cells activated

Answer 48

Antigen binds to an IgE receptor and activates adenylyl cyclase. leads to Calcium release which releases the primary mediators it also activates phopholipases- which converts arachidonic acid the membrane leading to the secretion of secondary mediators.

Question 49

What are mast cell primary mediators? how are they released

Answer 49

Histamine, heparin, eosinophil,neutropihl | released due to the Ca2+ and granule fusion. due to adenylyl cyclase cascade

Question 50

What are mast cell seconary mediators

Answer 50

Leukortienes, thromboxins, prostglandins | adenylyl cyclase activates phospholipases which converyt arachidonic acid in the membrane and these are secreted.