Anatomy Lecture 7 Surface Epithelium

Front 1

What are tissues?

Back 1

-Collections of cells with similar
1) Morphology
2) Function
3) Extracellular Matrix Around Them

Front 2

What is epithelial tissue?

Back 2

1) Closely adhering cells with little ECM
2) May arise from ectoerm, mesoderm, or endoderm
3) Avascular - exchange nutrients and wastes with CT via diffusion through the basal lamina

Front 3

What are the two types of epithelium?

Back 3

1) Surface Epithelium - covers external and internal body surfaces

2) Glands - forms the functional units of glands

Front 4

What is the function of the surface epithelium?

Back 4

1) Project underlying tissues and organs (skin)
2) Transports materials between tissues and organs (blood vessels)
3) Absorbs substances from a free surface or lumen - ex: GI tract or kidney tubules

Front 5

What are the types of surface epitheliums because some have specific names

Back 5

Mesothelium

Endothelium

Front 6

What is the mesothelium?

Back 6

Lining of pleural, pericardial and peritoneal cavities

Front 7

What is the endothelium?

Back 7

lining of lumen of blood vessels and lymphatics

Front 8

What is classification of surface epithelium based on?

Back 8

1) Number of cell layers that formed it

(Between free surface and basal lamina)

-Simple or stratified (several)

-Shape of cells at their free surface
-Squamous (flat), cuboidal, columnar

Front 9

Simple squamous epithelium

Back 9

Single layer of flat cells

Ex; lining blood vessels and body cavities

Front 10

Simple cuboidal epithelum

Back 10

Single layer of cuboidal cells

ex: kidney tubules

Front 11

Simple columnar epithelium

Back 11

single layer of columnar cells

ex: lining of digestive tract

Front 12

stratified squamous nonkeratinized epithelium

Back 12

several layers of cells with layer adjacent to free surface being flat cells ex; lining of esophagus

Front 13

stratified squamous keratinized epithelium

Back 13

several layers of cells with layer adjacent to free surface being flat cells but the cells in the superficial layer are dead and nuclei and cytoplasm are replaced by keratin

ex: epidermis of the skin

Front 14

stratified cuboidal epithelium

Back 14

2 or more layers of cells, top layer is cubodial

ex: ducts of sweat glands

Front 15

stratified columnar epithelium

Back 15

2 or more layers of cells of which the top layer is columnar
ex: some larger ducts of glands

Front 16

pseudostratified epithelium

Back 16

single layer of cells appear stratified as cells are different heights so all rest on basal lamina but not all reach sruface

ex: treachea

these have surface projections, cilia

Front 17

transitional epithelium

Back 17

stratified cells in which surface layer changes shape, tissue relax - cells rounded, tissue distended, cells squamous ex: most of urinary tract and bladder

Front 18

how is epithelial cell polarity formed?

Back 18

epithelial cells form cohesive sheets of cells so that their different surfaces are exposed to different enviornments
-these cells show surface polarity and intracellular polarity

Front 19

What are three types of surfaces of polarity?

Back 19

apical, lateral ,basal

Front 20

what is the apical surface

Back 20

free surface facing lumen, may have microvilli - increase surface area and cilia - moves particles along surface

Front 21

lateral surface

Back 21

has occluding junctions at apical part of surface to separate apical and basolateral surfaces and other junctions to maintain contact with adjacent cells

Front 22

basal surface

Back 22

specializations to interact with underlying basal lamina

Front 23

what is microvilli

Back 23

cytoplasmic projections of apical surface into lumen
contain mainly actin filaments

Front 24

cilia

Back 24

motile hair like projections that move substances over the surface
-composed of microtubules

Front 25

what are occluding (tight) junctions

Back 25

barrier preventing entry of material between cells
- possibly so tight that the membranes can fuse together

Front 26

what are anchoring junctions

Back 26

maintain cell to cell contact

Front 27

what are comunicating gap junctions

Back 27

movement of substances between cellls

Front 28

what is located in the basal end of the cell?

Back 28

usually nucleus, RER, mitochondria

Front 29

what is located in the apical end of the cell

Back 29

usually golgi apparatus, secretory vesicles

Front 30

what is in the lateral surface

Back 30

Occluding (tight) junctions – are close to the apical surface: prevent
exchange of material between surfaces in a cell or two adjacent cells
 Anchoring junctions – maintain cell-cell contact
 Communicating (gap) junctions – facilitate movement of material
between adjacent cells

Front 31

what is in the basal surface

Back 31

Specializations to interact with underlying basal lamina