Structure of the scalp

The scalp structure is very important to our physical health. Whether a person's scalp structure is healthy ensures that we are healthy when facing some things in our daily life. However, many people do not understand the scalp structure, and do not know how to judge it correctly. The following is an explanation of the scalp structure so that everyone can understand the scalp structure.

Scalp anatomy

Anatomy of the scalp: The scalp is the soft tissue covering the vault of the skull and can be divided into the frontal, parietal, occipital and temporal parts according to its location.

(1) Frontal, parietal and occipital regions

Range limits: anteriorly to the superior orbital margin, posteriorly to the external occipital protuberance and superior nuchal line, and laterally to the superior temporal line. The scalp has a 5-layer structure within this range. From outside to inside, they are:

1). Skin: Thick and dense, contains sweat glands, sebaceous glands, lymph, blood vessels, hair follicles and hair.

2). Subcutaneous tissue: It is composed of numerous lobules separated by dense connective tissue, filled with fat, blood vessels and nerves, and is located between the subcutaneous tissue and the galea aponeurotica.

3). Galea aponeurotica: a white, tough, membranous structure. It is connected to the frontalis muscle anteriorly, the occipital muscle posteriorly, and is fused to the superficial temporal fascia laterally, and can be considered a part of the parietal muscles. This layer is tightly connected to the skin by fiber bundles and loosely connected to the periosteum.

4). Subaponeurotic layer: It is a thin layer of loose connective tissue with many conducting blood vessels communicating with the intracranial venous sinuses. It is one of the pathways of venous sinus thrombosis and intracranial infection.

5). Periosteum: Attached to the surface of the skull, tightly attached at the cranial sutures and loosely attached at other parts, so subperiosteal hematoma can be localized.

(2) Temporal region

The upper boundary of this part is the superior temporal line, and the lower boundary is the upper edge of the zygomatic arch. It is divided into 6 layers: from outside to inside: skin, subcutaneous tissue, superficial temporal fascia, deep temporal fascia, temporalis muscle and periosteum. There is fat between the superficial and deep temporal fascia. The periosteum is tightly attached to the temporal bone and is difficult to separate.

The galea aponeurotica connects the frontal muscles in front and the occipital muscles in back to form the parietal muscles. There are three muscles distributed in a circular pattern on both sides with the ear as the center: the anterior auricular muscle, the superior auricular muscle and the posterior auricular muscle.

The subgaleal space is a potential gap between the galeal membrane and the periosteum, also known as the Merkel space. The loose connective tissue in the gap allows the upper layers to move flexibly. In addition, there are few blood vessels in this space. Therefore, when performing baldness scalp reduction surgery and living flap surgery, separation should be performed at this layer to reduce bleeding.

Deep in the subcutaneous tissue, just above the galea aponeurotica, there is a network of small arteries that are rich in blood vessels and provide blood supply to the scalp.

Blood vessels of the scalp The scalp is supplied with blood by five pairs of arteries: the supraorbital artery and supratrochlear artery in front, the superficial temporal artery and auricular artery on both sides, and the occipital artery behind. No artery passes through the skull and into the scalp. All arteries have abundant anastomoses with ipsilateral and contralateral vessels in both anterior and posterior directions and in both left and right directions. Therefore, scalp tissue can survive even if only 2 of these 10 arteries remain intact. The venous system runs along with the corresponding arterial network and flows into the jugular vein. There are some ductal veins that run from the scalp through the skull into the intracranial veins.