Epithelia are connected to underlying connective tissues by
A) a basement membrane only.
B) protein filaments embedded in glycoprotein only.
C) a basal lamina only.
D) a basement membrane and protein filaments embedded in glycoprotein only.
E) a basement membrane, protein filaments embedded in glycoprotein, and a basal lamina.

Question

Quizplus · Accepted Answer

Epithelia are connected to underlying connective tissues by a complex of three layers, namely a basement membrane, protein filaments embedded in glycoprotein, and a basal lamina. This complex is called the basement membrane complex, and it acts as a selective barrier between the epithelium and connective tissue, controlling the exchange of molecules and ions between the two tissues. The basement membrane is composed mainly of type IV collagen, laminin, and glycosaminoglycans, while the basal lamina is made up of specialized extracellular matrix proteins and glycoproteins. The protein filaments embedded in glycoprotein are called anchoring fibrils or hemidesmosomes, which anchor the basal surface of the epithelium to the basement membrane complex.

Epithelia Are Connected to Underlying Connective Tissues by