Cell Structure And Function Epithelium

Front 1

Epithelium Functions

Back 1

Secretion
Absorption
Transport
Protection
Sensory Perception
Excretion
Contractility

Front 2

Epithelium Distinguishing Characteristics

Back 2

Adhesions
Cohesive Groups
Basal Lamina
Regeneration
Polarity
Nourish via Diffusion
Nerves

Front 3

Epithelium Locations

Back 3

Lines Body Cavities
Skin
Blood Vessels
Glands

Front 4

Microvilli

Back 4

Actin structure connected to Actin Network
Function: increase surface area

Front 5

Motile Cilia

Back 5

9+2 anchored to 9(3), microtubules
Function: Movement of materials across cell surface

Front 6

Primary Cilia

Back 6

9+0 microtubules
Sensory Receptors
Bend Passively

Front 7

Nodal Cilia

Back 7

9+0 microtubules
embryonic development
left/right asymmetry

Front 8

Cell Junctions

Back 8

Occluding Junctions
Anchoring (adhesive) Junctions
Communication Junctions

Front 9

Occluding Junctions Structure

Back 9

Transmembrane Proteins- Claudins, Occludins
Intracytoplasmic Proteins- ZO proteins
Actin
Belt

Front 10

Occluding Junctions Function

Back 10

Continuous barrier to diffusion
Contribute to polarity by restricting specialized membrane structures

Front 11

Adherent Junctions Function

Back 11

Transmit stress forces to other cells or ECM
Cell Signaling

Front 12

Zonulae Adherens Structure

Back 12

Cell-to-Cell
Transmembrane Proteins: Cadherins
Linker/Anchoring Proteins: Catenins/alpha-actinin
microfilaments (F-actin)
Belt

Front 13

Desmosomes Structure

Back 13

Cell-Cell: Spot
Transmembrane Proteins: Cadherins (Ca dependent/independent)
Linker/Anchoring Proteins: plakoglobulin, desmoplakin
Intermediate Fibers

Front 14

Focal Adhesions Structure

Back 14

Cell-ECM
Transmembrane Proteins: Integrins
Linker/Anchoring Proteins: Viniculin, Talin, alpa-Actinin
Actin/Microfilaments

Front 15

Focal Adhesions Function

Back 15

Non-Epithelial Cell Migration through ECM
Attach Muscle Fibers to Tendon

Front 16

Hemidesmosomes Structure

Back 16

Cell-ECM
Transmembrane Proteins: Integrins
Intermediate Filaments

Front 17

Hemidesmosomes Function

Back 17

Attach Epithelia to Lamin in Basal Lamina

Front 18

Gap Junctions Function

Back 18

Direct solute exchange
Basis of electrical and metabolic coupling between cells
Vary with Type and Number of Connexins
Connect Excitable Cells
Transmit Signals

Front 19

Gap Junctions Structure

Back 19

Cell-to-Cell
Transmembrane Proteins: Connexins
Six Subunits, homo or heteromeric
Form hemichannels each cell has half the channel

Front 20

Gap Junction Regulation

Back 20

Rapid Reversible Opening and Closing
High Ca2+ close
Decrease pH Close
Extracellular Signal Ligands= Protein Kinase=Phosphorylate (PKA open, PKC close)

Front 21

Cadherins

Back 21

Strong long-term adhesions
Ca+2 dependent
homophilic
multiple types
link to Actin via Catenins

Front 22

Integrins

Back 22

Low affinity, transient adhesions
Ca+2 (divalent cations dependent)
heterophilic
transmembrane heterodimers
link to actin via alpha-actinin

Front 23

Integrin Function

Back 23

Clustering of Integrins can initiate intracellular signaling
ECM-Integrin-Actin: influence shape, orientation, movement via "stress fibers"
Change Integrins=interior changes (WBC adhesions)

Front 24

Immunoglobulin Siperfamily Cell Adhesion Molecuules (IgSF-CAMs)

Back 24

Low Affinity (multiple binding, velcro affect)
Ca+2 Independent
Repeating loops joined by disulfide bonds
homo or heterophilic interactions

Front 25

Selectins

Back 25

Ca+2 Dependent
heterophilic interactions via surface carbohydrates
Transient loose-binding (endothelium, blood cells)
Cell Activation via intracytoplasmic signaling

Front 26

Basal Lamina Structure

Back 26

Type IV Collagen
Lamin
Proteoglycans
Glycoproteins

Front 27

Reticular Lamina Structure

Back 27

Type III Collagen
Type VII Collegen (trap above) anchor
Fibrillin attach to elastic fibers

Front 28

Ca+2 Dependent

Back 28

Integrins
Cadherins
Selectins