What Is the Stratum Corneum?

The stratum corneum (Latin for 'horny layer') is the outermost part of the epidermis, which consists of 10 to 20 layers of flat, dead cells without nuclei. When these cells fall off, the underlying cells in the basal layer are pushed up, forming a new cuticle. Take the forearm of a human as an example, 1300 cuticle cells per hour per square centimeter of the epidermis fall off, forming fine dust. The outer layer of the stratum corneum that falls off is also called stratum dysjunction. The stratum corneum is the outermost layer of the epidermis and is composed of dead non-nucleated cornocytes (cornocytes). The main function of the stratum corneum is to protect its subcutaneous tissue from infection, dehydration, and resistance to stress caused by chemicals and machinery. The cells of the stratum corneum contain keratin. It helps reduce water evaporation and even absorbs water to keep the skin moist. Due to the water absorption of keratin, the skin of many animals (including humans) will wrinkle after being soaked in water for a period of time. The stratum corneum typically ranges from 10 to 40 microns, depending on how much protection is required for its corresponding body part. For example, the parts of the palms and soles that are in contact with the outside world and have more friction, the stratum corneum will be thicker. The stratum corneum of reptiles is a permanent tissue, and will only fall off and be replaced during high-speed growth (such as peeling). Their stratum corneum contains beta keratin, making their epidermis much harder than other animals.

Cuticle A layer of fatty material on the surface of above-ground organs of plants (such as stems, leaves, etc.). It is secreted by epidermal cells. It is most pronounced on the surface of the leaves; the outer layer of the epidermis of the shoots, flowers, fruits and young roots often has this structure. Its function mainly plays a protective role. It can not only limit the loss of water in the plant, but also promote the loss of water in the plant.

Like all animals, insects must breathe oxygen from their surroundings for blood circulation in order for their muscles and other body systems to function. But unlike other terrestrial animals, insects do not have lungs or similar breathing organs to deliver oxygen to the blood. So how do they breathe? Originally, their body surfaces were covered with small holes called breathing holes " These breathing holes can establish a connection with the blood of insects. Most exoskeletons of insects are made of waterproof, wax-like, shell-like chitin (also known as "chitin"), which gives Chitin can prevent their soft tissues from expanding. The only way for most insects to grow is to add new substances to expand the structure of their stratum corneum, or to completely remove the exoskeleton during the shelling process. Before the newly exposed inner chitin hardens, they become larger. Many insects, such as the tiger moth in the picture above, undergo this process when they change from larval pupae to adult form. But others Some insects, such as locusts, grow by shelling again and again ^[1]

The stratum corneum consists of 10 to 14 layers of flat keratinocytes that have died, and their nuclei and organelles have completely disappeared. Under the electron microscope, the stratum corneum cells are filled with dense and parallel keratin tension filaments immersed in the amorphous substance, among which are mainly the histidine-rich proteins contained in the transparent keratin. A layer of insoluble protein with a thickness of about 12 nm is attached to the inner surface of the cell membrane.

After the desquamation or artificial shedding of the stratum corneum, the epidermal layer rapidly proliferats keratinocytes and transforms the keratinocytes into dead, non-nucleated keratinocytes (cornocytes) and transports them to the skin surface. The process takes about 14 days. Excessive exfoliation will cause the stratum corneum to become very thin, sensitive skin, and severe red blood vessels. If it is caused by pure exfoliating products, it will cure itself after being discontinued. The red capillaries, the horny, are no longer there and have been destroyed. There are exogenous and endogenous types of red blood cells. Exogenous red blood cells are caused by products such as hormones, antibiotics, and fruit acids.

Daily prevention of red blood skin:

1. Enhance skin exercise, often wash your face with warm water to increase skin tolerance;

2. Try not to use cosmetics containing heavy metals to avoid pigmentation and residual toxins

(1) Apply an appropriate amount of exfoliating product to the fully washed face, and then use your fingertips to slide round and round around the face.

(2) Specially strengthen the massage in the T-shaped part, the sides of the nose and the lip area that are easy to produce oil, so that the dead spots that are easy to accumulate dirt can be thoroughly cleaned.

(3) Rinse the face with a large amount of water, so that all the dirt and old dead horns on the face are removed together, and the fair and radiant skin appears.

(4) Then use a cotton pad with a large amount of lotion to pat the skin on the face, so that the skin texture becomes fine, and the pores are reduced.