what is a basal membrane
The basement membrane is a thin, fibrous, extracellular matrix of tissue that separates the epithelium (skin, respiratory tract, gastrointestinal tract, etc), mesothelium (pleural cavity, peritoneal cavity, pericardial cavity, etc) and endothelium (blood vessels, lymph vessels, etc) from underlying connective tissue.he two layers together are collectively referred to as the basement membrane. The basal lamina layer can further be divided into two layers. The clear layer closer to the epithelium is called the lamina lucida, while the dense layer closer to the connective tissue is called the lamina densa.