Epithelial Tissues

Let’s review….

Simple cuboidal epithelium
 lining a tubule (longitudinal cut). Some of the cell boundaries between "blocks" or
"cubes" here are quite distinct.

Simple Cuboidal
 Covers surface of ovary, lines kidney tubules and small ducts of glands (thyroid and pancreas)

Tubule - cross section simple cuboidal

Another example - kidney

Type?

Simple squamous epithelium
 High power view of endothelial cells lining a small blood vessel cut in cross-section.
(You see just the nuclei - the cytoplasm between them is extremely flat.)
Endothelium = the simple squamous epithelium lining blood vessels.

Simple squamous epithelium

Kidney

Superficial view
(squamous)

Type?

Simple columnar
 Another example – intestine, with goblet

Intestinal lining

Yet another

Type?

Pseudostratified ciliated columnar epithelium
Trachea. Nuclei are at different levels. All cells touch the basement membrane, but only the taller cells reach the lumen. The cilia are longer and less regular than the microvilli of a striated border.

Pseudostratified
Columnar Epithelium
 Look like multiple layers
 Trachea
Figure 4–5b

Another example

Cilia – surface view

Type?

Bladder Low power

Transitional Epithelium
 Tolerates stretching
 Appearance changes (stratified to simple)
 Urinary bladder
Figure 4–4c

Type?

Stratified Squamous Epithelium
Figure 4–3b

Example

Example

Type?

Type?

Stratified Cuboidal Epithelium
 Sweat gland ducts
Figure 4–4b

Type?

Stratified Columnar Epithelium
 Rare
 Salivary gland duct
Figure 4–5c

Note
 It is the shape of the most superficial layer that determines what type of stratified epithelium it is.

Today’s procedure
 Set up microscope
 Get a slide
 Follow instructions in Lab Manual
 Hints
 Start on low power and locate epithelium (this is the bulk of the work)
 Go to 10x, then 40x
 Draw tissue
 Return slide to box you got it from .

Today’s lab
 Examine and draw at least one of each type of epithelial tissue
 Activity 1:
 Simple squamous – two options: kidney glomeruli, mesothelium
 Simple cuboidal – kidney tubules
 Simple columnar – large intestine (frog, human)

Today’s lab
 Examine and draw
 Activity 2:
 Psuedostratified ciliated columnar – trachea
 Transitional – ureter

Today’s lab
 Examine and draw
 Activity 3:
 Stratified squamous (skin, oral smear, frog superficial view)
 Stratified columnar (salivary gland)
 No stratified cuboidal (don’t need to do)

Lab Write up
Turn in:
 7 drawings on page I provide
 Parts A, B, C, only
 Due next week on TUes