Written by Dr. Griffin
A Philadelphia-Area Physician Explains How the Scalp and Hair Follicles Work
Why is it important to understand scalp anatomy? The Philadelphia-based Dr. Thomas Griffin at the Griffin Hair Restoration Center explains that the condition of our scalp—which is the part of the head that consists of the skin and soft tissue that cover the cranium—influences the overall condition of our hair. A scalp anatomy is considered to be healthy and balanced when there aren’t any signs of conditions affecting it, such as itchiness, oiliness, redness, flakiness, irritation, pain, acne, sun damage, hair breakage, slow hair regrowth, or hair loss.
Learn all about scalp anatomy from the Philadelphia-based team at The Griffin Hair Restoration Center of Philadelphia. Ready to explore advanced treatments for hair loss? Reach out by calling (215) 561-9100, or submit a contact form to request a consultation.
Why Is It Important to Maintain a Healthy Scalp?
Basically, the scalp itself has a major influence on the appearance and health of the hair. In some ways, scalp care may even be considered more of a priority than hair care. A healthy scalp stimulates optimal hair growth and promotes a flourishing head of hair. Conversely, scalp disease, infections, and skin disorders can lead to hair thinning and loss.
Just as we maintain a skincare routine to prevent premature aging, we also need to give our scalp the care and protection it needs to encourage the growth and maintenance of healthy hair follicles. However, most people know little about scalp anatomy, and the scalp itself can be one of the most overlooked or neglected areas of the body, as we usually focus more on the hairs that grow from it.
The scalp is continuously subjected to harmful effects from the environment, especially UV radiation from the sun. The resulting damage can accumulate over a lifetime, leading to cosmetic and medical conditions. Much like the skin on other areas of the body, skin that is part of the scalp also weakens over time and becomes drier. In addition, skin cell generation slows. This makes it more difficult for the scalp to maintain healthy hair. When scalp issues aren’t treated, they can eventually lead to hair loss.
Scalp Anatomy 101: Layers of the Scalp
The scalp anatomy consists of five tissue layers: skin, connective tissue, aponeurosis, loose connective tissue, and periosteum. Conveniently, the layers can be remembered as “SCALP.” Together, the layers create an intricate structure that runs from the face to the back of the neck and covers the cranial vault.
- Skin – The thick outermost layer that contains hair follicles and sebaceous glands, which secretes an oil-like substance that lubricates the skin and hair.
- Connective tissue – The layer beneath the skin (subcutaneous layer) that consists of fibrous tissue and fat. It contains the main blood vessels and nerves of the scalp, which notably give the scalp the richest blood supply of any area of the skin on the body.
- Aponeurosis – A tough, fibrous layer that connects the frontalis muscle to the occipitalis muscle, two muscles that cover the front and back of the skull, respectively.
- Loose connective tissue – A thin layer that separates the lowest layer (periosteum) from the upper three layers and gives the scalp its mobility.
- Periosteum – The dense layer of connective tissue that nourishes and adheres to the bone.
The skin is the layer of the scalp anatomy that contains the mechanism responsible for manufacturing hair: the follicle.
A Closer Look at Scalp Anatomy: Hair Follicles
Hair follicles, which are found in the dermal portion of the skin and extend deep into the scalp, are the structures of the scalp anatomy responsible for producing hair as well as oils to keep the skin moisturized while reducing the risk of infection. At any given point, normal hair follicles are in one of three phases of the hair growth cycle: growth, transition, and resting.
A complex system within the scalp anatomy contains nutrients delivered via the bloodstream and nerves that receive signals from the brain. When the environment of the scalp is thrown out of balance, the disruption can lead to dermatitis, dandruff, and other problems. Patients who suffer from hair loss disorders can be diagnosed as having genetic reasons for the condition and/or hair follicles damaged by inflammation.
Scalp Anatomy Disruptions: Damaged Hair Follicles
Bacterial or fungal infections can cause inflammation of the hair follicles (known as folliculitis), which, if severe and persistent, can damage follicles and cause them to shut down. Skin conditions such as psoriasis or dandruff can irritate the scalp and prompt incessant scratching—a habit that can exacerbate the problem, damage hair, and impede growth. Lupus and lichen plano pilaris cause inflammation that harms the follicle. Follicles may also be injured and damaged beyond repair by certain processing procedures, such as straightening and tight braids or extensions.
If the scalp becomes injured, scar tissue can develop and irreversible hair loss may result. To prevent such loss, scalp conditions should be evaluated and appropriately treated, especially where an injury or inflammation is present. Patients should make an effort to protect their hair from sun damage, avoid overusing products or using overly harsh products, maintain balanced moisture levels, and not wash their hair too frequently or infrequently.
Find out more about scalp anatomy from the Philadelphia-based team at The Griffin Hair Restoration Center of Philadelphia. To learn about treatments for thinning or damaged hair, call (215) 561-9100 or submit a contact form to request a consultation.