1

EPITHELIUM TISSUECHARACTERISTICS:

*MOST named by number of layers and cell shape*AVASCULAR*Located as covering or lining of hollow organs, cavities, or vessels

– know specific location of each type & function*ID lumen, basement membrane, nucleus, & specialized structures*Specialized structures:

-cilia, stereocilia, microvilli, goblet cells, and keratin (know function and location)

ORGANIZATION:I. Single layer

a. Simple Squamousb. Simple Cuboidalc. Simple Columnard. Pseudostratified Columnar

II. 2 or more layersa. Stratified Squamousb. Stratified Cuboidalc. Stratified Columnard. Transitional

ADDITIONAL SLIDES:GI – Slide 9 (GE junction)GI – Slide 14 (Duodenum)GI – Slide 21 (Colon)MALE – Slide 15 (Epididymis)URINARY – Slide 16 (Ureter)

EPITHELIUM - SLIDE 1A – KIDNEY (GLOMERULUS)

lumen

Basement membrane

Simple Squamous (1): Simple Cuboidal (2):(Bowman’s Capsule) (Collection Ducts)FXN: filtration, diffusion, FXN: absorption; secretionSecretion.

1

2

2

3

EPITHELIUM - SLIDE 1B – AVEOLI (LUNGS)

lumen lumen

lumenBasement membrane

Simple Squamous:FXN: Gas diffusion

EPITHELIUM - SLIDE 2 – THYROID GLAND (1); KIDNEY (2)

lumenlumen

Basement membrane

Simple Cuboidal:FXN: secretion (1); absorption (2)

Nucleus

4

lumen

lumen

Basement membrane

EPITHELIUM - SLIDE 3A– GALL BLADDER

lumen

Basement membrane

Simple Columnar – Nonciliated (1): Areolar CT(2):LCN: GI (stomach-anus), ducts, GB LCN: “packing material”FXN: Secretion, absorption FXN: Strength, elasticity, and support

1

2

Collagen Fibers

RBCs in capillaries:**d/t epithelium is AVASCULAR**

Ground Substance

Fibroblast:Flat cells w/ branching processes

MacrophageCells

5

6

EPITHELIUM – SLIDE 3B BRONCHIOLES

Ciliated Simple Columnar (1): Dense Irregular CT (2):Respiratory tract (bronchioles), uterine tubes Less ground substanceFXN: trap and move particles FXN: tensile strength in across surface; oocyte transport many directions

1

2

lumen

Basement membrane

EPITHELIUM - SLIDE 4 – TRACHEA

Pseudostratified Columnar (1): Dense Irregular CT (2):Ciliated w/ Goblet Cells: Less ground substanceUpper respiratory tract FXN: tensile strength in many directionsFXN: trap and move particles across surfaceNon-ciliated w/o goblet cells: Larger ducts, epididymis, male urethra

Basement membrane

lumen

1

Cilia

2

Collagen Fibers

7

EPITHELIUM - SLIDE 5A – LIP

Basement membrane

External area

Nuclei

Stratified Squamous – Nonkeratinized (aka: Moist):LCN: lining of mouth, esophagus, and vaginaFXN: protection and first line of defense from microbes

8

**Flat nucleus on apical surface**

9

EPITHELIUM - SLIDE 5B – SKIN

Stratified Squamous – Keratinized (1):LCN: Superficial layer of the skinFXN: First line of defense from microbes; *protection from heatwater loss, and UV light*.Be sure to refer to Chapter 5 to determine specific layers of the Integumentary system.

Basement membrane

*Keratin*

External area

1

2 DCT

10

EPITHELIUM - SLIDE 6 – SWEAT GLANDS

Stratified Cuboidal: **no more than 2 layers**LCN: ducts of sweat & esophageal glands, male urethraFXN: Limited secretion (thermal regulation) & absorption

Basement membrane

lumen

11

EPITHELIUM - SLIDE 7

Stratified Columnar: **no more than 2 layers**LCN: part of urethra, some large ducts, conjunctiva of eye FXN: Limited secretion and absorption

Basement membrane

lumen

12

EPITHELIUM - SLIDE 8 –

Transitional: **don’t confuse with stratified squamous**LCN: Urinary bladder, ureters, and urethraFXN: Stretch without rupturing (distention)

Basement membrane

lumen

**Rounded surface in relaxed state; with round nuclei**