Stratifed epithelia, skin, human, H&E ×450. (StCu) in two layers; the cells of the inner layer (the surface cells) appear more or less square. Because the epidermal surface cells are not included in This shows a portion of the duct of a sweat gland just before the field, the designation stratified squamous cannot be derived from the in- the duct enters the stratified squamous epithelium (SS) of formation offered by the micrograph.
the skin. The dashed line traces the duct within the epidermis. This duct also consists of a stratified cuboidal epithelium
PLATE 3 • STRATI FI E D E PITH E LIA AN D E PITH E LIOI D TI SS U E S KEY C, capillary CT, connective tissue En, endocrine cells Ex, exocrine cells IC, interstitial (Leydig) cells SCol, simple columnar epithelium SS, stratified squamous epithelium StCu, stratified cuboidal epithelium arrowhead, transition site of simple stratified epithelium to stratified cuboidal arrows, surface cuboidal cells asterisks, dome-shaped cells
Epithelial transition, anorectal junction, human, H&E ×300.
The area shown here is the terminal part of the large intestine. The luminal epithelium on the left is typical simple columnar epithelium (SCol) of the colon. This epithelium undergoes an abrupt transition (arrowhead) to a stratified cuboidal epithelium (StCu) at the anal canal. Note the general cuboidal
Transitional epithelium (urothelium), urinary bladder, monkey, H&E ×400.
The epithelium of the urinary bladder is called transitional epithelium, a stratified epithelium that changes in appearance according to the degree of distension of the bladder. In the nondistended state, as here, it is about four or five cells deep. The surface cells are large and dome shaped (asterisks). The cells
Epithelioid tissues, testis, monkey, H&E ×350.
This shows the intestinal (Leydig) cells of the testis (IC). These cells possess certain epithelial characteristics. They do not possess a free surface, however, nor do they develop from a surface; shape of most of the surface cells (arrows) and the underlying layers of cells. The simple columnar epithelium on the left is part of an intestinal gland that is continuous with the simple columnar epithelium at the intestinal luminal surface. The connective tissue (CT) at this site is heavily infiltrated with lymphocytes, giving it an appearance unlike the connective tissue of other specimens on this page.
immediately under the surface cells are pear shaped and slightly smaller. The deepest cells are the smallest, and their nuclei appear more crowded. When the bladder is distended, the superficial cells are stretched into squamous cells, and the epithelium is reduced in thickness to about three cells deep. The bladder wall usually contracts when it is removed, unless special steps are taken to preserve it in a distended state. Thus, its appearance is usually like that in Figure 4.
instead, they develop from mesenchymal cells. They are referred to as epithelioid cells because they contact similar neighboring cells much the same as epithelial cells contact each other.  Leydig cells are endocrine in nature.
Epithelioid tissues, endocrine pancreas, human, H&E ×450.