Is the third layer of the epidermis the basement membrane? Is this also called the stratum basale layer?
No, basement membrane is not the third layer of epidermis. And stratum basale is not basement membrane.
The skin is the heaviest organ of our body, It is composed of epidermis and dermis. The hypodermis, a layer of loose connective tissue beneath the dermis is not considered as a part of the skin.
The epidermis is a stratified squamous keratinized epithelium. It consists of 5 layers of Keratin-producing cells (keratinocytes) . From the dermis outward these are :
1. Stratum Basale
2. Stratum Spinosum
3. Stratum Granulosum
4. Stratum Lucidum
5. Stratum Corneum
The diagram below shows different layers of epidermis. The numbers 1 to 5 in the left indicates 5 layers as mentioned earlier.
The basement membrane of epidermis is also can be seen in this diagram. The basal layer (stratum basale) rests upon it.