MUCOUS MEMBRANE. 41 
When mucus is formed in a layer of cylindrical or ciliated cells how 
is it discharged ? 
It is extruded from the apparently open end of the cell as a little 
droplet. These cells are swollen, and from their shape are called 
goblet or chalice cells, 
What is the situation of the corium ? 
It is a membrane composed of connective or retiform tissue, bounded 
on the side next the epithelium by a basement membrane and sepa- 
rated from the sub-mucous coat by a thin layer of invcluntary muscle 
(muscularis mucose). 
What is the structure of the basement membrane ? 
Where it is present it is made up either of a layer of flattened cells, 
which may lie edge to edge, forming a perfect sheet, or of a layer of 
branching cells which when arranged together have spaces between 
them. 
What is the structure of the corium ? 
It is made up of fibrous connective tissue, which may be rather 
dense and tough, or may consist of retiform connective tissue contain- 
ing patches of lymphoid tissue. 
What is the sub-mucous coat? 
It is a layer of areolar connective tissue between the muscularis 
mucosz and the outer muscular wall of a cavity as seen in the intestine. 
What is the distribution of bloodvessels, lymphatic vessels, and 
nerves in mucous membrane ? 
The vessels are most abundant in the sub-mucous coat, and send 
branches into the mucous membrane proper. The nerves are princi- 
pally distributed to the muscularis mucosz and may send filaments up 
between the epithelial cells of the mucous membrane. Before dividing 
they may in many parts be collected to form a gangliated plexus 
in the sub-mucous coat, as, for example, Meissner’s plexus ia the walls 
of the intestine. 
Describe the free surface of mucous membranes. 
They may be plain and smooth, or they may be beset with little 
eminences named papillx or villi, derived from the corium. 
‘What forms of secreting glands occur in the mucous membrane ? 
Simple, tubular and racemose glands. 
