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Flashcards in Histology - Epithelium Flashcards Deck (63)
1

Extracellular matrix layer between epithelial cells and underlying CT. Carbohydrate base.

Basement membrane

1

bands encircling the cell, linking adjaent cells together. Resists mechanical separation of cells.

zonula adherens

1

integrin used as adhesive moleculelinking basal lamina to cytoskeleton.

Cell-Matrix Junctions

2

do not normally undergo mitosis, however retains ability if organ damaged or needs increase (ex, hepatocytes).

Stable epithelium

2

bacteria in GI tract that attacks tight junctions and causes ulcers.

Helicobacter pylori

2

Adheren Junctions (Zonula adherens)

E-cadherin (grey dots at TEM) inserted into intracellular space and fuse together and linked to Actin filaments. Zonula (Belt) all the way around the cell. Resist mechanical separation and maintains sheet-like structure. Found in Epithelium and Cardiac muscles

2

Microvilli

Short projections of the apical membrane and cytoplasm of lumen w/ associated Glycocalyx. Composed of plasma membrane surrounding Actin Filament Core which is anchored to a terminal web (actin). Forms a brush border (flat top haircut).

3

Occludin and Claudins

Claudins join in the intercellular space to form Junctional Strands

5

actin filmamentous core, cross linked to plasma membrane and other actin binding proteins. Anchored to Terminal Web (TW) (also actin).

Microvilli core skeleton

7

only a few, no mitosis (adult), eg, cells in core of lens, hair cells, inner ear.

Permananet Epithelium

7

Uncontrolled proliferation of cells (failure of normal regulatory mechanisms)

Neoplasia

8

3-4 longer than MV, less 'orderly'. Specialized to move substances along a surface.

Cilia

9

steady state renewable, replace cells that are ocntinuously lost, with rpesent stem cells. Proliferation is highly regulated (ex: epidermis, epithelium of GI tract, respiratory system, urogential systems)

Labile epithelium

10

No CAMs, have transmembrane connexons. Aid in cell-cell communication.

Gap junctions

10

tight junction, barrier to paracellular transport.

Zonula Occuldens

11

Lateral Folds

Increases surface area through interdigitation of plasma membrane of adjacent cells, aiding in Fluid and Electrolyte transportation via Transcellular pathway.

12

Focal Adhesion

Integrin proteins linked to basal lamina outside cell and Actin Filaments inside cell. Aids in adhesion and mechanosensitivity.

12

Adaptor Proteins

Supress proliferation of epithelial cells.

14

Transcellular transport

Transcellular transportExchange of substances to/from lumen and CT by passing through an epithelial cell. Active process.

14

associated with aubdant mitochondria that increase surface area for active ion transport.

Basal folds

15

BL (basal lamina) + RL (reticular lamina) (at TEM level)

BM (at light level)

16

a carcinoma featuring microscopic glandular-related tissue cytology, tissue architecture, and/or gland-related molecular products, e.g., mucin.

Adenocarcinoma

17

interact with desmosomes (cell-cell adhesion) and hemidesmosomes (cell-matrix adhesion) via adapter proteins.

Intermediate filaments

17

problem with adhering type junctions, cells pull apart and space fills with fluid.

blistering

19

Covers, lines, secretes, absorbs

Epithelium

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a cell junction whose cytoplasmic face is linked to the actin cytoskeleton.

Adherens junctions

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influecne lots of process that occur within cell, one is suppress proliferation (contact inhibition).

adaptor molecules

22

Epithelial cells adjacent to the wound site divide, giving rise to new epithelial cells. The new epithelial cells detach and migrate laterally along the remnants of the basal lamina that are still present.

Wound healing

23

a belt like intercellular junction located between adjacent lateral domains immediately "above" the adherens junction. No CAMs, connected by transmembrane proteins. Help define functional domains (apical-basolateral) - establishing polarity and limit paracellular transport.

tight junction

23

Wound repair

Loss of adaptor proteins causes epithelial cellad and stem cells adjacent ot wound to proliferate. New epithelial cells detach and migrate along basement membrane.

23

Cilia

Long projections used for movement of substances and cells, synchronized movement. Less organized, 9+2 arrangement of microtubules.

24

Cell-to-Matrix Adherents

Hemidesmosomes, Focal Adhesions

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Apical specilization that establishes extracellular microenvironments at membrane surface. Functions: metabolism, cell regocnition, receptor sites etc. Composed of: glycoproteins and glycolipids.

Glycocalyx

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orderly series of 3 junctions, tight junction, adherens junction (ZA), desmosome (D) - terminal bar at light level.

Junctional complex (@ TEM)

27

Blisters

Strong abrasionand sheering disrupts Focal Adhesions causing separation of epithelial cells from connective tissue and fluid accumulation.

28

Apical Domain

Directly Contacts Luminal Contents or External Area

30

is an assembly of six proteins that can be a part of a gap junction channel between the cytoplasm of two adjacent cells. Two come together to complete intercellular gap junction channel.

connexon

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a benign tumor of epithelial tissue with glandular origin, glandular characteristics, or both.

adenoma

33

Interdigitations of plasma membrane of adjacent cell lateral comains located below levelk of the junctional complex that increases surface area for interlocking cells and fluid and electrolyte transport via transcellular pathway.

Lateral Folds

34

Apical Folds

Increase surface area for mainly absorption and secretion between lumen/external environment

35

Integrins

transmembrane receptors that are the bridges for cell-cell and cell-extracellular matrix (ECM) interactions. When triggered, integrins in turn trigger chemical pathways to the interior (signal transduction)

36

Hemidesmosomes

Integrin proteins attached to Basal lamina outside cell and attachment plaque inside cell. Keratin intermediate filaments strengthen them by adhering to attachment plaque. Resists abrasion, sheering, and tearing forces between Epithelial Cells and Basal Lamina. Strong attachment between epithelial cell and basal lamina.

37

Special arrangement of microtubules. 9 outer doublets, and 2 central singlets. Abbreviated "9+2". Anchored into the basal body.

Cilia core

38

Cell-to-Cell Adherents

Adheren Junctions (Zonula adherens), Desmosome (Macula adheren)

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proteins located on the cell surface involved in binding with other cells or with the extracellular matrix (ECM) in the process called cell adhesion.

Cell adhesion molecules (CAMs)

41

a type of cancer that develops from epithelial cells.

carcinoma

42

Weave back and forth through each cell’s plasma membrane several times

transmembrane proteins

43

9 triplets

Basal body MT composition

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occludin and claudins that weave through each cell's plasma membrane and extend into ICS.

Transmembrane proteins

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rows of transmembrane proteins from adjacent cells that appear as ridges or stitches that act as a barrier to paracellular transport pathway.

Junctional strands

48

a type of connective tissue that has a network of reticular fibers, made of type III collagen and only in this lamina are they dominant. Have anchoring fibers and plaques (loops). Thickness varies with frictional force applied to overlying Epi.

reticular lamina

50

directly contacts the luminal contecnts or external environment. Site of absorption and secretion.

Apical domain

51

types of large macromolecular assemblies through which both mechanical force and regulatory signals are transmitted that serve as the mechanical linkages to the ECM, at sites of integrin binding and clustering.

focal adhesions

53

Desmosome (Macula adheren)

Desmosome Cadherin (CAM) insert into intercellular space and overlap each other, inserted into attachment plaque inside cell. Strengthened by keratin intermediate filaments.

54

localized spot-like adhesions randomly arranged on the lateral sides of plasma membranes. help to resist shearing forces and are found in simple and stratified squamous epithelium. 'velcro dots'

desmosome

55

a layer of extracellular matrix secreted by the epithelial cells, on which the epithelium sits. Functions: attachment epithelium to CT, regulation/filtration: exchange b/w E + CT, scaffolding (for regeneration).

basal lamina

56

Tight Junction (Zonula Occludens)

Transmembrane proteins (Occludins and Clausind) weaved back and forth through both cell’s plasma membrane several times that blocks molecular movement between intercellular space. Wrap around cell like a belt. Establishes polarity in cell.

57

Formation of cell/tissue masses as the result of the proliferation of neoplastic cells.

Tumor

59

short, finger-like projections of the apical plasma membrane & cytoplasm into the lumen. Very uniform and itghly packed. Increase SA for absorption (and secretion).

Microvilli

60

Paracellular Transport

Exchange of small solutes, ions, and water between lumen and connective tissue between the lateral domains. Also allows movement of White blood cells into the Connective tissue

61

small stud- or rivet-like structures on the inner basal surface of keratinocytes in the epidermis of skin that attach one cell to the extracellular matrix.

hemidesmosomes

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zonula adherens, intermediate junction, or "belle desmosome"

Adherens junctions names

63

Exchange of small solutes, ions, and water to/from lumen and CT by pasing netween lateral domains. Passive provess.

Paracellular transport