What might if we had simple squamous instead of stratified squamous epithelium on our skin? happen?
Note that the skin is the major barrier between the inside and outside of your body.
- The outermost layer of the skin — the epidermis is a keratinized, stratified, squamous epithelium. Superficial layer of epidermis is made of dead cells.
- Melanocytes which produce melanin are found in the stratum basale layer. Melanin protects cells from damage by UV, by producing a 'veil' over the nucleus.
- Lamellar bodies are secreted by Keratinocytes which fuse with cell membrane and an impermeable barrier is formed on skin.
- This along with keratin laden dead cells of superficial layer prevent entry of microbes through skin surface, unless there is any injury on the skin.
Without these defense mechanisms, water and moisture would leak out, we’d be very susceptible to pathogens crossing the single squamous epithelium (SSE) and we’d be subjected to the daily harmful UV rays of the sun.
I want to reiterate the important functions of the skin.
Protection : it protects against UV light, mechanical, thermal and chemical stresses, dehydration and invasion by micro-organisms.
Sensation : skin has receptors that sense touch, pressure, pain and temperature.
Thermoregulation : various features of the skin are involved in regulating temperature of the body. For example sweat glands, hair, and adipose tissue.
Metabolic functions: subcutaneous adipose tissue is involved in production of vitamin D, and triglycerides.
(There’s a purpose to why SSE are located in the capillaries, lung alveoli, glomeruli, mainly because this lining functions for rapid diffusion of gases, nutrients and wastes rather than protecting the host from gargantuan external threats.)