Skin Layers Diagram: Labeled 3D Model of the Layers of the Skin

The skin has three main layers. From the surface down they are the epidermis, a thin sheet of cells with no blood vessels; the dermis, a thick layer of connective tissue that holds blood vessels, nerves, hair follicles and glands; and the hypodermis (subcutaneous layer), made of fat and loose connective tissue. Strictly, the hypodermis lies under the skin and is not part of it, but nearly every skin layers diagram includes it.

The epidermis is itself made of four or five layers called strata (singular: stratum). From deep to superficial they are the stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (only in thick skin) and stratum corneum. The dermis has two layers: a thin papillary layer under the epidermis and a thick reticular layer below it.

A labeled diagram of the layers of the skin shows the epidermis at the top, the dermis with its hair follicles, glands, vessels and nerve endings in the middle, and the fatty hypodermis at the bottom. The diagram below labels 26 structures, the same set most biology, anatomy and cosmetology courses ask students to identify.

Read a skin diagram from the top down. The hair shaft and sweat pores are on the surface. The wavy line under the epidermis is the dermal–epidermal junction; the bumps pushing up into the epidermis are dermal papillae, each holding a capillary loop or a Meissner corpuscle. In the dermis, the hair follicle runs at a slant, with the sebaceous gland and arrector pili muscle on the side the hair leans toward. The coiled sweat glands sit near the bottom of the dermis, and the onion-like Pacinian corpuscle sits deep, near or in the fat.

Anatomists say the skin has two layers, the epidermis and the dermis, resting on a third, the hypodermis. Most school courses simply teach three layers of skin and include the hypodermis. The answer "five" refers to the five strata of the epidermis, not to the whole skin.

You will also see the phrase "seven layers of skin". This is a popular way of counting, not a standard anatomical term. It usually adds the five epidermal strata to the dermis and the hypodermis (5 + 1 + 1). It is a useful memory aid, but it mixes levels: the five strata are sublayers of one tissue, while the dermis and hypodermis are whole layers with their own sublayers. Thin skin, which covers most of the body, has only four epidermal strata, so the count would be six there.

The five layers of the epidermis, from deepest to most superficial, are the stratum basale, stratum spinosum, stratum granulosum, stratum lucidum and stratum corneum. A common memory aid, reading from the surface down, is "Come, Let's Get Sun Burned": corneum, lucidum, granulosum, spinosum, basale.

• Stratum basale: Renews the epidermis. It also holds the melanocytes, which make pigment, and the Merkel cells, which sense touch.
• Stratum spinosum: Gives the epidermis strength and flexibility. Its cells begin making keratin, and it holds the immune Langerhans cells.
• Stratum granulosum: Makes keratin and keratohyalin and releases lipids that seal the spaces between cells, forming the water barrier.
• Stratum lucidum: Adds an extra tough, translucent layer to skin that takes heavy friction and pressure.
• Stratum corneum: Forms the main barrier of the skin. Keratin and lipids between the cells stop water loss and keep out microbes, chemicals and minor abrasion.

Cells of the epidermis

Four cell types live in the epidermis. In the 3D model they are drawn on the front cut face of the thin-skin block, in the window at the front right.

• Keratinocytes: Build the protective, waterproof barrier of the skin from keratin and lipids.
• Melanocytes: Make melanin and pass it in small packets (melanosomes) to nearby keratinocytes, where it shields the cell nuclei from UV light.
• Langerhans cells: Catch microbes and foreign material that get into the epidermis and present them to the immune system.
• Merkel cells: Together with their nerve ending (the Merkel disc) they sense sustained light pressure and the texture and shape of objects.

The epidermis and dermis are joined at the dermal–epidermal junction, a basement membrane that is folded into ridges and bumps. Finger-like dermal papillae push up into the epidermis, and epidermal (rete) ridges push down between them. The folding increases the contact area, which strengthens the bond and brings capillaries within diffusion distance of the basal cells.

• Dermal–epidermal junction: Anchors the epidermis, resists shearing forces and controls which molecules and cells pass between the two layers.
• Dermal papillae: Increase the contact area between the dermis and epidermis, strengthen the junction and bring capillaries close to the avascular epidermis.
• Capillary loops: Exchange oxygen, nutrients and wastes with the epidermis, which has no blood vessels of its own.

Papillae are taller and more crowded in thick skin, which has to resist friction. In the fingertips the pattern of papillae sets the pattern of the fingerprint before birth. Compare the two blocks in the 3D model: the thick-skin block on the right has much taller papillae.

The dermis is the thick middle layer of the skin, made of connective tissue produced by fibroblasts. It has two layers. The papillary layer is thin, loose areolar tissue just under the epidermis. The reticular layer is much thicker, dense irregular tissue packed with collagen and elastin, and forms most of the skin's thickness. There is no sharp line between them.

• Papillary dermis: Feeds the epidermis through its capillaries and houses lymphatic capillaries, nerve endings, Meissner corpuscles and immune cells.
• Reticular dermis: Gives skin its strength (collagen) and its stretch and recoil (elastin), holds water, and supports hair follicles, glands, vessels and nerves.

The hypodermis is the layer of fat and loose connective tissue under the dermis. It is also called the subcutaneous layer, subcutis or superficial fascia. It is not strictly part of the skin, but it anchors the skin to the fascia over muscles and bones while letting it slide, and its fat insulates, cushions and stores energy.

• Hypodermis: Anchors the skin to the muscles and bones while letting it slide, and stores fat for insulation, cushioning and energy.
• Adipose tissue (fat lobules): Stores energy as fat, insulates against heat loss and cushions against knocks.

The hypodermis varies more than any other layer. It can be several centimeters thick over the belly and buttocks and is almost absent from the eyelids. The largest blood vessels and nerves that supply the skin run through it, and so do the deep roots of large hair follicles, apocrine glands and Pacinian corpuscles.

A hair follicle is a tube of epidermis that dips deep into the dermis. The hair shaft is the part above the skin; the hair root is the part inside the follicle. At the base, the swollen hair bulb wraps around the hair papilla, a knob of connective tissue with capillaries and nerve endings. Dividing cells in the bulb, the hair matrix, make the hair and the inner root sheath.

• Hair shaft: Insulates, protects the skin from sunlight and abrasion, and senses touch when it is bent.
• Hair root: Anchors the hair; new cells added at the bulb push the root and shaft upward as the hair grows.
• Hair bulb: Contains the hair matrix, a layer of rapidly dividing cells that makes the hair and the inner root sheath. Melanocytes here color the hair.
• Hair papilla: Brings blood capillaries and nerve endings to the hair matrix and sends signals that control hair growth.
• Inner root sheath: Shapes and supports the growing hair, then breaks down so the hair can leave the follicle.
• Outer root sheath: Lines and supports the follicle. Its bulge region holds stem cells that can regrow the hair and repair nearby epidermis after a wound.
• Arrector pili muscle: Contracts when the sympathetic nervous system fires (cold or fear), pulling the hair upright and making goose bumps.
• Hair follicle plexus: Senses when a hair is bent, so you can feel an insect walking on your arm before it touches the skin.

The hair shaft itself has three layers: a central medulla (missing in some hairs), a cortex and a hard outer cuticle. Hair colour comes from melanin made by melanocytes in the bulb. In the 3D model, click the hair bulb or a root sheath to see the follicle on its own; the sheaths are drawn as cut-open sleeves.

Skin has three main types of gland. Sebaceous glands make oily sebum and empty it into hair follicles. Eccrine sweat glands make watery sweat for cooling and open through their own pores. Apocrine sweat glands, in the armpits and groin, make a thicker secretion and empty into hair follicles.

• Sebaceous gland: Secretes sebum, which lubricates and waterproofs the skin and hair, keeps the stratum corneum supple and has antibacterial fatty acids.
• Eccrine sweat gland: Makes hypotonic sweat that cools the body as it evaporates. Sweat also carries the antimicrobial peptide dermcidin.
• Sweat duct: Delivers sweat to the surface and reabsorbs some of the salt on the way, so sweat ends up more dilute than blood.
• Sweat pore: Releases sweat onto the surface, where it evaporates.
• Apocrine sweat gland: Makes a thicker, milky secretion rich in proteins and lipids. Skin bacteria break it down, which causes body odour.
• Apocrine duct: Carries apocrine sweat into the follicle, from which it reaches the surface along the hair.

The skin is supplied by two flat networks of vessels in the dermis. The cutaneous (deep) plexus lies at the junction of the dermis and hypodermis; the subpapillary (superficial) plexus lies just under the dermal papillae. Vessels connect the two, and capillary loops rise from the subpapillary plexus into the papillae. Lymphatic capillaries begin as blind-ended tubes in the papillary dermis and drain down to larger lymph vessels.

• Cutaneous arterial plexus: Distributes oxygen-rich blood to the skin and sends branches to hair bulbs, sweat glands and up to the subpapillary plexus.
• Cutaneous venous plexus: Collects oxygen-poor blood from the skin and drains it into the veins of the hypodermis.
• Subpapillary arterial plexus: Supplies the capillary loops of the dermal papillae and so, by diffusion, the whole epidermis.
• Subpapillary venous plexus: Drains blood from the papillae down to the deep venous plexus.
• Lymphatic vessels: Collect excess tissue fluid, proteins and immune cells from the dermis and return them to the blood via the lymph nodes.
• Cutaneous nerve: Carry touch, pressure, vibration, temperature and pain signals to the spinal cord, and autonomic signals to sweat glands, vessels and arrector pili muscles.

Skin has at least six kinds of sensory receptor, each at a typical depth. Free nerve endings and Merkel discs are at or in the epidermis, Meissner corpuscles in the dermal papillae, Ruffini endings in the dermis, and Pacinian corpuscles deep in the dermis and hypodermis. Nerve endings wrapped around hair follicles sense hair movement.

• Free nerve endings: Sense pain, heat and cold, and itch, as well as some touch.
• Merkel discs: Slowly adapting touch receptors: they keep firing during sustained pressure and signal edges, shapes and texture.
• Meissner corpuscle: Rapidly adapting receptor for light touch and low-frequency vibration (below about 40–50 Hz), such as an object slipping in your grip.
• Ruffini ending: Slowly adapting receptor thought to sense skin stretch, which helps you feel finger position and object shape.
• Pacinian corpuscle: Rapidly adapting receptor for deep pressure and high-frequency vibration, best around 200–250 Hz.

Each layer of the skin has its own main jobs. The epidermis is the barrier; the dermis gives strength, feeling, temperature control and the glands; the hypodermis insulates and cushions. Together they make the skin the body's largest organ.

Thick skin covers the palms, the fingertips and the soles of the feet. It has five epidermal strata, including the stratum lucidum, a very thick stratum corneum and friction ridges, but no hair follicles or sebaceous glands. Thin skin covers the rest of the body. It has four strata, no stratum lucidum, and has hair follicles, sebaceous glands and arrector pili muscles.

"Thick" and "thin" describe the epidermis, not the whole skin. The skin of the back has a thin epidermis but a very thick dermis, so it is thin skin even though it is thick to the touch. In the 3D model, the right-hand block is thick skin: look for the clear stratum lucidum, the deep stratum corneum, the friction ridges with pores along their crests, and the Meissner corpuscles in the papillae.

Facial skin has the same layers as skin elsewhere, but it is mostly thin skin with a thinner epidermis, many hair follicles and a very high density of sebaceous glands. Sebaceous glands reach about 400–900 per square centimeter on the forehead and scalp, far more than on the limbs, which is why the face is prone to oiliness and acne.

Skin thickness varies a lot across the face. In an ultrasound study of 38 facial sites, the upper eyelid had the thinnest skin (median about 0.57 mm in total) and the tip of the nose the thickest (about 1.9 mm). The eyelid also has almost no subcutaneous fat, which is why it shows swelling and bruising so easily. Facial skin also contains mimetic (expression) muscles that insert into the dermis, which is part of why expression lines form there.

In a standard H&E-stained section, the epidermis is the thin, darker pink-to-purple band of packed cells at the top, the dermis is the paler pink fibrous layer under it, and the hypodermis shows as clear, empty-looking fat cells, because the fat dissolves during processing.

• Stratum basale: one row of small, dark-nucleated cuboidal or columnar cells along the wavy junction. Melanocytes show as pale, clear cells among them.
• Stratum spinosum: several layers of larger pink polygonal cells with round nuclei; the "spines" are desmosomes stretched between cells that shrank during processing.
• Stratum granulosum: flattened cells full of dark purple (basophilic) keratohyalin granules, easy to spot as a dark line.
• Stratum lucidum: in thick skin only, a thin, glassy, pale band with no nuclei.
• Stratum corneum: pink layers of flat dead cells with no nuclei, often split into a basket-weave by processing. It is huge in palm or sole sections and thin in thin skin.
• Dermis: fine, loosely woven fibers in the papillary layer and thick, wavy collagen bundles in the reticular layer, with cut follicles, glands and vessels.

To tell thick from thin skin on a slide, look for a stratum lucidum, a very thick stratum corneum and deep interdigitations between epidermis and dermis (thick skin), or hair follicles and sebaceous glands (thin skin).

Burns are classified by how many layers of the skin they destroy. A superficial (first-degree) burn affects only the epidermis. A partial-thickness (second-degree) burn reaches into the dermis: superficial partial-thickness burns stop in the papillary dermis, deep partial-thickness burns reach the reticular dermis. A full-thickness (third-degree) burn destroys the whole epidermis and dermis and reaches the fat. Some systems add a fourth degree for burns into muscle or bone.

The anatomy explains the symptoms. Partial-thickness burns hurt because the nerve endings of the dermis survive and are exposed. Full-thickness burns often hurt less because those nerve endings are destroyed. And a burn can heal on its own only if some epidermal cells survive, in hair follicles and sweat ducts deep in the dermis, to regrow the surface. Once the whole dermis is gone, there is nothing left to regrow from except the wound edges. This page is for learning; anyone with a significant burn needs medical care.

This is the text version of the 3D model: every labeled structure, grouped by layer and system, with what it does. Use it as a study list or to check a skin diagram worksheet.

The epidermis is replaced from the bottom up. Stem cells in the stratum basale divide, and each new keratinocyte is pushed upward by the cells made after it. In the stratum spinosum it starts making keratin; in the stratum granulosum it fills with keratohyalin, flattens, and its nucleus and organelles break down. By the time it reaches the stratum corneum it is a dead, flat scale of keratin. The whole stratum corneum is replaced in about four weeks. (OpenStax Anatomy & Physiology 2e, 5.1 Layers of the skin.)

This is why the epidermis can lose its outer cells all day without wearing through. Hair follicles are part of the same system: the outer root sheath of each follicle is a downward extension of the epidermis, and the hair itself is made of keratinized cells produced by the matrix in the hair bulb. (OpenStax Anatomy & Physiology 2e, 5.2 Accessory structures of the skin.)

The epidermis has no blood vessels of its own. Every living epidermal cell depends on oxygen and nutrients that diffuse up from the capillary loops in the dermal papillae. The deepest cells are the best fed; as cells move away from the dermis their supply falls, which is one reason they die as they approach the surface. (OpenStax Anatomy & Physiology 2e, 5.1 Layers of the skin.)

Each type of touch receptor sits at a different depth and answers a different question. Merkel cell–neurite complexes in the basal epidermis are slowly adapting: they keep firing while you press on something, and signal edges and texture. Meissner corpuscles in the dermal papillae of hairless skin adapt quickly and respond to light touch and low-frequency vibration under about 40 Hz, such as an object starting to slip from your fingers. (Zimmerman, Bai & Ginty (2014): the gentle touch receptors of mammalian skin, Science.)

Pacinian corpuscles lie deep in the dermis and in the hypodermis. Their many layers act as a filter, so they respond best to high-frequency vibration around 200 Hz. In the adult human hand they reach 3 to 4 mm long. Ruffini endings in the dermis are thought to sense skin stretch, though the link between stretch-sensing nerve fibers and the Ruffini capsule is still described as a hypothesis. (Zimmerman, Bai & Ginty (2014): the gentle touch receptors of mammalian skin, Science.)

OpenStax lists the same receptors with their classic and modern names: free nerve endings (pain, temperature, some touch), Merkel discs (low-frequency vibration around 5–15 Hz), bulbous corpuscles or Ruffini corpuscles (stretch), tactile or Meissner corpuscles (light touch, vibration below 50 Hz), lamellated or Pacinian corpuscles (deep pressure, vibration around 250 Hz) and the hair follicle plexus (movement of hairs). Different sources give slightly different frequency figures because they come from different experiments. (OpenStax Anatomy & Physiology 2e, 14.1 Sensory perception (Table 14.1, mechanoreceptors).)

A review of regional sweating data estimated that a typical adult with 1.8 square meters of skin has about 2.03 million working eccrine sweat glands. They are not spread evenly: the palm averages about 518 glands per square centimeter and the sole about 497, against about 103 on the back. (Taylor & Machado-Moreira (2013): regional variations in eccrine sweat gland density and sweating, Extreme Physiology & Medicine.)

Each eccrine gland is a single tube. Its secretory coil, deep in the dermis within the first 3 mm of the skin, is about 3.5 mm long and 40 µm wide. The duct runs fairly straight up through the dermis, then becomes a spiral as it crosses the epidermis to open at a pore. (Taylor & Machado-Moreira (2013): regional variations in eccrine sweat gland density and sweating, Extreme Physiology & Medicine.)

Even when you are not visibly sweating, about 500 mL of water a day leaves the body as insensible perspiration. During hard exercise in the heat, an active person can sweat 0.7 to 1.5 liters an hour, and the evaporation of that sweat is the body's main way of shedding heat. (OpenStax Anatomy & Physiology 2e, 5.3 Functions of the integumentary system.)

Skin diagrams, including the 3D model on this page, draw the epidermis far too thick so its layers can be seen. A meta-analysis of 133 studies of healthy people found that epidermal thickness ranges from about 31 µm (0.03 mm) on the penis to about 597 µm (0.6 mm) on the sole of the foot, across 37 body sites. The epidermis gets thinner with age; differences between sexes and ethnic groups were minor. (Lintzeri et al. (2022): epidermal thickness in healthy humans, a systematic review and meta-analysis, JEADV.)

On the face, the upper eyelid has the thinnest skin. A high-frequency ultrasound study of 38 sites on the faces of 45 women found a median total skin thickness of about 574 µm on the upper eyelid, against about 1,907 µm at the tip of the nose. (Korzekwa et al. (2025): human face skin thickness by high-frequency ultrasound, Journal of Clinical Medicine.)

Histology of the upper eyelid of 61 Korean women gave a mean epidermis of 49 µm and dermis of 811 µm at 7 mm above the lashes. Total thickness fell from about 1,127 µm just below the eyebrow to about 320 µm at the lash margin, where the epidermis made up 11% of the total. (Hwang (2013): surgical anatomy of the upper eyelid, Anatomy & Cell Biology.)

Blood reaches the skin through vessels that perforate the underlying muscle and fat and form a deep horizontal network at the base of the dermis. Vessels rising from it form a second, superficial network just under the dermal papillae. From this upper network, capillary loops rise into the papillae at right angles to the surface, and side branches from the vessels linking the two networks supply hair bulbs and sweat glands. (Bottino & Bouskela (2023): non-invasive techniques to assess the skin microcirculation, Frontiers in Medicine.)

The dermal blood supply is also a thermostat. When the body is hot, dermal arterioles dilate so more warm blood flows near the surface and loses heat; in the cold they constrict to keep heat in the core. That is why skin flushes in a hot bath and turns pale in the cold. (OpenStax Anatomy & Physiology 2e, 5.3 Functions of the integumentary system.)

Test yourself with this unlabeled diagram of the skin layers. Name the three main layers marked A, B and C, then the 26 numbered structures. Cover the answer key, write your answers, then check. Anatomy, nursing and cosmetology courses (including the textbooks used for esthetics licensing) use this kind of diagram, so it makes a good worksheet.

Quick quiz

1. Which epidermal layer is found only in thick skin? (Stratum lucidum.)
2. In which stratum do new keratinocytes form? (Stratum basale.)
3. Which layer of the skin has no blood vessels? (The epidermis.)
4. Name the two layers of the dermis. (Papillary and reticular.)
5. Which gland empties into the hair follicle and makes sebum? (Sebaceous gland.)
6. Which receptor senses deep pressure and fast vibration? (Pacinian corpuscle.)
7. Which muscle causes goose bumps? (Arrector pili.)
8. A burn has blisters and is very painful. How deep is it? (Superficial partial-thickness: into the papillary dermis.)

Related topics: nerve signals from skin receptors are explained on the action potential diagram page, and the rest of the body is in our 3D human anatomy model.