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Histology Exam 1 TonyFrim > Connective Tissue and ECM > Flashcards

Flashcards in Connective Tissue and ECM Deck (76):
1

Connective tissue consists of cells embedded in an

extracellular matrix

2

Connective tissue is composed of

fibers, amorphous ground substance, and tissue fluid

3

Connective tissue is classified based on

type of cells, type and arrangement of fibers, character of ground substance

4

Functions of Connective Tissue (4)

1)Structural support 2) exchange medium between blood and tissues 3)defense and protection 4)fat storage

5

Most connective originates from what germ layer?

Mesoderm

6

Fibroblasts

CT cell, secretes proteoglycans , glycoproteins, different collagen types (especially Type I) and elastin

7

Fibroblast arise from what type of cells

mesenchymal cells

8

Shape of fibroblasts

Spindle shaped

9

Fibrocytes

When fibroblasts are quiescent (smaller and more slender)

10

When actively making ECM components, fibroblasts have well developed...

rER and Golgi

11

Adipocytes arise from what type of cell

Mesenchymal cells

12

Adipocytes are surrounded by

basal lamina

13

What forms can adipocytes be found in

unilocular (white) and multilocular (brown)

14

Unilocular cells with a single large fat droplet have

receptors for insulin, growth hormone, norepinephrine, and glucocorticoids

15

Two uses for adipocytes include

fat storage (white) or heat generation (brown)

16

Macrophages originate from ______ _______ as ______

bone marrow ; monocytes

17

3 different phenotypes of macrophages in the body and where they are located

Kuppfer cells in liver; osteoclasts in bone; microglia in CNS

18

Function of macrophage

phagocytic but also regulator of immune system

19

Mast cells contain Fc receptors for

IgE

20

Important mediator of allergic hypersensitivity reactions (asthma, hay fever, eczema)

Mast cells

21

Mast cells arise from what cells

Mast cells arise from myeloid stem cell during hematopoiesis

22

Mast cells release mediators that are

vasoactive or increase inflammatory response

23

Some mediators released by mast cells

leukotriene C, heparin, histamine, eosinophil chemotactic factor (ECF), aryl sulfatase, neutral protease and neutrophil chemotactic factor

24

Mast cells contain _____________ staining granules

metachromatic

25

Mast cells mediate why type of hypersensitivity reactions

Type I hypersensitivity reactions

26

Antibody producing cells that arise from activated B lymphocytes (ovoid with eccentrically placed nucleus with spoke-wheel arranged heterochromatin)

Plasma cells

27

Lymphocytes arise from what type of cells in bone marrow

Lymphoid stem cells

28

Where do T cells differentiate

Thymus

29

B cells function in ________ immune response

humoral

30

T cell function in ____________ immunity

cell-mediated

31

First cell that appears in inflammatory response

Neutrophils

32

Neutrophils

contain specific granules and azurophilic granules; trilobed nucleus; Phagocytic

33

Most abundant WBC in bloodstream

Neutrophils

34

Bind to antigen-Ab complex on parasite surface and release cytotoxins

Eosinophils

35

Eosinophils contain enzymes that

cleave histamine and leukotriene C to moderate allergic reaction

36

Eosinophil nucleus is

bilobed

37

Eosinophil granules contain

crystalloid inclusions

38

Pericytes

mesenchymal-like stem cells. Found around capillaries

39

Role of pericytes in wound healing

In wound healing, pericytes may differentiate into fibroblasts or smooth muscle cells

40

Mucous CT

Jelly like matrix containing some collagen and fibroblasts

41

Main component of umbilical cord

Mucous CT (Wharton's jelly)

42

Amorphous matrix with some reticular fibers and mesenchymal cells. (CT present in embryos)

Mesenchymal CT

43

Specialized CT

bone, cartilage, blood

44

Loose CT

Well vasularized with abundant ground substance and small nerve fibers (Fibroblasts, macrophages, lymphocytes, mast cells, mesenchymal cells all may be present)

45

Dense irregular CT

Fiber bundles have no particular orientation. (most abundant type of DENSE CT; found in dermis, organ capsules)

46

Dense regular CT

Fiber bundles arranged in uniform manner. (Contain fibrocytes)

47

Dense regular CT is only found in

tendons and ligaments

48

ECM consists of

ground substance, fibers and tissue fluid

49

Ground substance consists of

proteoglycans

50

Proteoglycans

core protein with covalently linked glycosaminoglycans

51

Glycosaminoglycans

unbranched polymers of repeating disaccharides which may be sulfated or nonsulfated

52

To form large aggregates(aggrecan) proteoglycans may attach to _______ _____ via core protein

hyaluronic acid

53

Glycoproteins

macromolecules that bind ECM components to each other and to cell integrins

54

Chondroitin sulfate

Glycosaminoglycan of repeating disaccharide units with D-glucuronic acid and N-acetyl-D-galactosamine sulfated at 4 or 6 position

55

Chondroitin sulfate is abundant in

hyaline and elastic cartilage

56

Hyaluronic acid

Free in ECM. Component of cartilage, synovial fluid, citrous humor. Nonsulfated. Helps maintain hydration of cartilage.

57

Fibronectin

460K MW glycoprotein with 2 subunits bound together by -S-S- bridges. Cellular form widely found in CT cells and cell surfaces.Binds collagen, heparin, and mediates cell adhesion to ECM.

58

Laminin

Component of basement membranes. 2 polypeptide chains that form cross shaped aggregate. Binds to INTEGRINS, heparan sulfate, type IV collagen and entactins.

59

Tenascin

Adhesin GP found in embryonic tissues. function in cell migration

60

Tenascin is secreted by

glial cells of developing nervous system

61

Collagen fibers

Composed of type 1 collagen; consists of closely packed 75nm diameter tropocollagen fibrils

62

Reticular fibers

Primarily type III collagen; argyrophilic staining(silver); loosely packed 45nm diameter tropocollagen fibrils

63

Elastic fibers consist of

elastin and fibrillin microfibrils in amorphous elastin

64

Type I collagen

(90% of collagen in body) Bone, skin, tendons, dentin, scar tissue. Fibroblast, osteoblast, odontoblast

65

Type II collagen

Hyaline cartilage and some in elastic cartilage. Also vitreous body of eye and nucleus pulpous of IV discs. Chondroblast

66

Type III collagen

Fetal skin, reticular fibers.Granulation tissue. Fibroblasts, SMC, Schwann cell, hepatocyte

67

Type IV collagen

Basement membranes. fibrils have no striations

68

Type VII collagen

Beneath epithelial basement membranes. Fibrils anchor basement membrane to connective tissue

69

Elastin

Amorphous structural protein; molecules highly cross linked via lysine residues

70

2 unusual amino acids in elastin

desmosine and isodesmosine

71

Fibrillin (Type I and II)

Component of peripheral microfibrils around elastic fibers

72

Glycoprotein that helps link fibrillin together

MAGP (microfibril-associated glycoprotein)

73

ECM remodeling

process involves breakdown of existing, and synthesis and deposition of new ECM proteins

74

Main class of proteolytic enzymes involved in ECM remodeling

matrix metalloproteinases (MMPS)

75

Scurvy

Vitamin C deficiency; decreased proline hydroxylation of collagen

76

Plasma form of ______ dissolved in blood and involved in clotting and wound healing

Fibronectin