Page 18 - Chapter 3: Cells and Tissues

a. Continuous sheets (Figure 6-1)

The cells fit together snugly like tiles.

b. One surface is always unattached
Epithelial tissue has two surfaces. One surface is always
unattached, like the surface of the outer skin or the inner lining
of the mouth. The undersurface is attached to a basement
membrane.

c. It is avascular
Epithelial tissue has no blood supply of its own. For its nourishment
depends on the blood supply of underlying connective
tissue.

d. It is able to regenerate
Because epithelial tissue is so well nourished from the
underlying connective tissue, it is able to regenerate, or
repair itself, quickly if injured.

I. Glandular epithelia
a. Exocrine glands
i. Secrete into ducts which carry the secretions onto a
surface
ii. Examples: saliva, sweat, digestive enzymes

b. Endocrine glands
i. Secrete into the blood that transports the hormones
throughout the body
ii. Considered ductless glands
iii.Examples: insulin, growth hormone, steroids