Human Skin Anatomy
The skin is the largest organ of the body, with an overall area of about 20 square feet. The skin secures us from microbes and the elements help manage body temperature and allows the feelings of touch, heat, and cold.
The color, density, and texture of skin differ over the body. There are two general types of skin; thin and hairy, which is more prevalent on the body, and thick and hairless, which is discovered on parts of the body that are utilized greatly and withstand a big amount of friction, like the palms of the hands or the soles of the feet.
Layers of the Skin
The Cutaneous Membrane
The cutaneous membrane is the technical term for our skin. The skin’s primary role is to assist and protect the remainder of the body’s tissues and organs from physical damage such as abrasions, chemical damage such as detergents, and biological damage from microbes. For example, while the skin harbors many long-term and transient bacteria, these bacteria are not able to go into the body when healthy, undamaged skin is present.
Our skin is made of 3 basic layers. In order from many superficial to inmost, they are the epidermis, dermis, and hypodermis or subcutaneous tissue.
The epidermis is a thin layer of skin. It is the most superficial layer of skin, the layer you see with your eyes when you look at the skin anywhere on your body. Functions of the epidermis consisting of touch feeling and protection against microorganisms.
This skin is additionally divided into five, separate layers. In order from a lot of shallows to deepest, they are the:
- Stratum Corneum
- Stratum Lucidum
- Stratum Granulosum
- Stratum Spinosum
- Stratum Basale
This layer is composed of the many dead skin cells that you shed into the environment– as a result, these cells are found in dust throughout your house. This layer helps to ward off water.
This layer is found only on the palms of the hands, fingertips, and the soles of the feet.
This is the layer where part of keratin production takes place. Keratin is a protein that is the primary component of the skin.
This layer provides skin strength as well as versatility.
This is where the skin’s most important cells, called keratinocytes, are formed before moving up to the surface area of the epidermis and being shed into the environment as dead skin cells. This layer likewise consists of melanocytes, the cells that are largely responsible for figuring out the color of our skin and safeguarding our skin from the hazardous effects of UV radiation. These harmful impacts include burns in the short-term and cancer in the long run.
Beneath the skin lies the dermis. The dermis includes:
Blood vessels that nourish the skin with oxygen and nutrients. The capillary also enables body immune system cells to come to the skin to combat viruses. These vessels likewise help carry away waste products.
Nerves that help us relay signals coming from the skin. These signals include touch, temperature, pressure, discomfort, and itching.
Numerous glands, Hair follicles, Collagen, a protein that is accountable for giving skin strength and a little elasticity.
Hypodermis or The Subcutaneous Tissue
The inmost layer of the skin is called the subcutaneous layer, the subcutis, or the hypodermis. Like the dermis, the layer includes blood vessels and nerves for similar reasons.
Notably, the subcutis consists of a layer of fat. This layer of fat works alongside the capillary to maintain an appropriate body temperature. The layer of fat here serves as a cushion against physical trauma to internal organs, muscles, and bones. Additionally, the body will rely on this fat in times of starvation to offer energy to its various processes, particularly brain function.
Specialized cells and Structures of Skin
The skin includes numerous specialized cells and structures:
Basket cells surround the base of hair follicles and can sense pressure. They are examined when assessing total nerve health and condition.
Blood vessels bring nutrients and oxygen-rich blood to the cells that make up the layers of skin and carry away waste items.
Hair Erector Muscle (Arrector Pili Muscle)
The arrector pili muscle is a small muscle linked to each hair follicle and the skin. When it contracts it triggers the hair to stand erect, and a “goosebump” forms on the skin.
The hair follicle is a tube-shaped sheath that surrounds the part of the hair that is under the skin and nourishes the hair. It lies in the epidermis and the dermis.
The hair shaft is the part of the hair that is above the skin.
These cells attach themselves to antigens that invade harmed skin and notify the immune system about their existence.
A melanocyte is a cell that produces melanin and is located in the basal layer of the skin.
Merkel cells are tactile cells of neuroectodermal origin located in the basal layer of the epidermis.
A Pacinian corpuscle is a nerve receptor located in the subcutaneous fat that responds to pressure and vibration.
Sebaceous glands are little, sack-shaped glands that release an oily substance onto the hair roots that coat and safeguards the hair shaft from becoming breakable. These glands lie in the dermis.
The epidermis is innervated with sensory nerves. These nerves sense and transmit heat, discomfort, and other noxious sensations. When they are not working correctly experiences such as tingling, pins-and-needles, numbness, or burning might be felt. When evaluating a skin biopsy, total number, contiguity, size, branching, swelling, and overall health of the sensory nerves are evaluated.
Sweat Gland (Sudoriferous Gland)
These glands lie in the skin and produce moisture (sweat) that is produced through tiny ducts onto the surface of the skin (stratum corneum). When sweat vaporizes, the skin temperature level is lowered.
There are two main kinds of sweat glands:
Eccrine glands— the significant gland of the human body. They release a clear, odorless compound, comprised mostly of sodium chloride and water– which is associated with thermoregulation.
Apocrine glands— bigger gland, located in the axillary and genital regions. These apocrine glandular products can be broken down by cutaneous microbes, producing body odor.
Functions of Skin
- The skin supplies a necessary barrier in between the external environment and internal body contents. It safeguards against mechanical, chemical, osmotic, thermal, and UV damage, and microbial intrusion.
Its other functions consist of:
- A role in the synthesis of vitamin D.
- Maintenance of body temperature level.
- A major sensory organ for touch, temperature level, pain, and other stimuli.