Description: The biggest single organ in the body, accounting for 15% to 20% of total body weight and exposing 1.5 to 2 m2 of surface area to the external environment in adults.
Function: Thermoregulation, Blood reservoir, Protection, Cutaneous sensations, Excretion and absorption, Synthesis of Vitamin D
Description: Deepest, single layer of cuboidal to low columnar cells in contact with basement membrane; mitosis occurs here; melanocytes and Merkel cells also
Function: Proliferation and attachment of the epidermis to the dermis
Location: The basement membrane (basal lamina) separates the dermis from the lowest layer, which is linked to the basement membrane by hemidesmosomes.
Description: The stratum spinosum (also known as the spinous layer or prickly cell layer) is an epidermal layer that lies between the stratum granulosum and the stratum basale.
Function: Responsible for skinās strength and flexibility
Location: The stratum spinosum (also known as the spinous layer or prickly cell layer) is an epidermal layer that lies between the stratum granulosum and the stratum basale.
Description: the epidermis layer just beneath the stratum corneum or (on the palms and soles) just beneath the stratum lucidum; contains dying and moving cells (with visible granules). They begin to shed their nuclei and cytoplasmic organelles, transforming into keratinized squames of the next layer. A lipid-rich secretion found in the granules works as a water sealant.
Function: Act as a transitional layer where keratinocyte skin cells develop into their final form and die
Location: above the stratum spinosum and below the stratum corneum (stratum lucidum on the soles and palms)
Description: Each distal phalanx has hard keratin plates on the dorsal surface.
Function: The role of a healthy fingernail is to protect the distal phalanx, fingertip, and surrounding soft tissues from injury. It also helps to improve exact sensitive movements of the distal fingers by applying counter-pressure to the finger pulp.
Location: Dorsal surface of each distal phalanx of the fingers and toes
Description: the proximal region of the thickened nail matrix, which appears as a white crescent
Function: The lunula has a crucial structural role in defining the distal nail plate’s free edge. Anomalies of the lunula include alterations in form, structure, and color.
Location: It is located at the beginning of our nail bed and is part of our nail matrix.
Function: a diffusion barrier that restricts water and nutrient transport across the apoplast and protects the plant against chemical and mechanical harm, as well as pest and pathogen attack
Location: The cuticle is an epidermal cell’s exterior, periclinal cell wall that is also extruded between anticlinal walls.
Description: the thickened proximal part of the nail bed containing germinal cells responsible for nail growth
Function: The nail matrix is the starting point for the growth of your fingernails and toenails. The matrix generates new skin cells, pushing out the old, dead ones to form your nails.
Location: The nail matrix can be found beneath the base of the finger or toe nail.
Description: extension of the stratum basale beneath the nail
Function: The nail body is created on the nail bed and protects the tips of our fingers and toes, which are the body’s farthest extremities and face the most mechanical stress.
Location: The skin beneath the nail plate is known as the nail bed.
Function: The nail plate serves as a sharp extension of the phalanx for climbing, scratching, and digging for food while also supporting the underlying dorsal surface of the distal phalangeal pad.
Location: The proximal nail fold gives way to the nail plate, which is bordered on both sides by the lateral nail folds (paronychium).
Description: Connective tissue, blood vessels, oil and sweat glands, nerves, hair follicles, and other structures are all found in the dermis. The papillary dermis is the thin upper layer, and the reticular dermis is the thick lower layer.
Function: It has a variety of purposes, including shielding your body from the elements, supporting your epidermis, sensing various sensations, and creating sweat.
Location: located between your epidermis (top layer) and hypodermis (bottom layer) in your skin.
Description: Connective tissue, blood vessels, oil and sweat glands, nerves, hair follicles, and other structures are all found in the dermis. The papillary dermis is the thin upper layer, and the reticular dermis is the thick lower layer.
Function: Protection. The epidermis functions as a shield to protect your body from harmful UV rays, pathogens (bacteria, viruses, fungus, and parasites), and chemicals.
Structure of five layers of the skin
Skin
Description: The biggest single organ in the body, accounting for 15% to 20% of total body weight and exposing 1.5 to 2 m2 of surface area to the external environment in adults.
Function: Thermoregulation, Blood reservoir, Protection, Cutaneous sensations, Excretion and absorption, Synthesis of Vitamin D
Location: Covers the body’s exterior surface.
Stratum Basale
Description: Deepest, single layer of cuboidal to low columnar cells in contact with basement membrane; mitosis occurs here; melanocytes and Merkel cells also
Function: Proliferation and attachment of the epidermis to the dermis
Location: The basement membrane (basal lamina) separates the dermis from the lowest layer, which is linked to the basement membrane by hemidesmosomes.
Stratum Spinosum
Description: The stratum spinosum (also known as the spinous layer or prickly cell layer) is an epidermal layer that lies between the stratum granulosum and the stratum basale.
Function: Responsible for skinās strength and flexibility
Location: The stratum spinosum (also known as the spinous layer or prickly cell layer) is an epidermal layer that lies between the stratum granulosum and the stratum basale.
Stratum Granulosum
Description: the epidermis layer just beneath the stratum corneum or (on the palms and soles) just beneath the stratum lucidum; contains dying and moving cells (with visible granules). They begin to shed their nuclei and cytoplasmic organelles, transforming into keratinized squames of the next layer. A lipid-rich secretion found in the granules works as a water sealant.
Function: Act as a transitional layer where keratinocyte skin cells develop into their final form and die
Location: above the stratum spinosum and below the stratum corneum (stratum lucidum on the soles and palms)
Stratum Lucidum
Description: the epidermal layer in the skin of the palms and soles just beneath the stratum corneum
Function: Capability of the skin to stretch, degeneration of skin cells, effects of friction in skin
Location: It is found on the palms of the hands and the soles of the feet.
Stratum Corneum
Description: The stratum corneum is the epidermis’s outermost layer, marking the end of keratinocyte maturation and development.
Function: Prevents unwanted materials from entering and loss of water from exiting the body.
Location: The stratum corneum is the epidermis’ outermost layer (skin).
Structure of the nail
NAIL
Description: Each distal phalanx has hard keratin plates on the dorsal surface.
Function: The role of a healthy fingernail is to protect the distal phalanx, fingertip, and surrounding soft tissues from injury. It also helps to improve exact sensitive movements of the distal fingers by applying counter-pressure to the finger pulp.
Location: Dorsal surface of each distal phalanx of the fingers and toes
Free Edge
Description: The free edge of the nail bed, also known as the nail tip, protrudes beyond the end of the finger.
Function: this ensures that all the nail bed is covered and therefore protected.
Location: Nails
Nail Groove
Description: The depression between the nail plate’s borders and the skin.
Function: The grooves on the underside of the nail plate span the length of the nail and help secure it to the nail bed.
Location: Nails
Nail Fold
Description: skin folds that overlap the borders of the nail
Function: It secures the nail and protects it while it develops.
Location: The fold is connected to the cuticle, which is attached to your nail.
Lunula
Description: the proximal region of the thickened nail matrix, which appears as a white crescent
Function: The lunula has a crucial structural role in defining the distal nail plate’s free edge. Anomalies of the lunula include alterations in form, structure, and color.
Location: It is located at the beginning of our nail bed and is part of our nail matrix.
Nail Body
Description: the visible attached portion
Function: The sensitive tips of fingers and toes are protected by nails.
Location: Nails
Cuticle
Description: the thick proximal nail fold
Function: a diffusion barrier that restricts water and nutrient transport across the apoplast and protects the plant against chemical and mechanical harm, as well as pest and pathogen attack
Location: The cuticle is an epidermal cell’s exterior, periclinal cell wall that is also extruded between anticlinal walls.
Phalanx
Description: Any of the long bones of the fingers or toes, numbering 14 for each hand or foot
Function: In 50 percent of fingertip injuries, the distal phalanx, which provides bone support for the nail bed, is fractured.
Location: Nails
Nail Matrix
Description: the thickened proximal part of the nail bed containing germinal cells responsible for nail growth
Function: The nail matrix is the starting point for the growth of your fingernails and toenails. The matrix generates new skin cells, pushing out the old, dead ones to form your nails.
Location: The nail matrix can be found beneath the base of the finger or toe nail.
Nail Bed
Description: extension of the stratum basale beneath the nail
Function: The nail body is created on the nail bed and protects the tips of our fingers and toes, which are the body’s farthest extremities and face the most mechanical stress.
Location: The skin beneath the nail plate is known as the nail bed.
Nail Plate
Description:
Function: The nail plate serves as a sharp extension of the phalanx for climbing, scratching, and digging for food while also supporting the underlying dorsal surface of the distal phalangeal pad.
Location: The proximal nail fold gives way to the nail plate, which is bordered on both sides by the lateral nail folds (paronychium).
Hyponychium
Description: The hyponychium is the skin directly beneath your nail’s free edge.
Function: The hyponychium acts as a barrier against pathogens and debris, preventing them from entering your nail.
Location: It’s near your fingertip, just beyond the distal end of your nail bed.
Dermis
Description: Connective tissue, blood vessels, oil and sweat glands, nerves, hair follicles, and other structures are all found in the dermis. The papillary dermis is the thin upper layer, and the reticular dermis is the thick lower layer.
Function: It has a variety of purposes, including shielding your body from the elements, supporting your epidermis, sensing various sensations, and creating sweat.
Location: located between your epidermis (top layer) and hypodermis (bottom layer) in your skin.
Epidermis
Description: Connective tissue, blood vessels, oil and sweat glands, nerves, hair follicles, and other structures are all found in the dermis. The papillary dermis is the thin upper layer, and the reticular dermis is the thick lower layer.
Function: Protection. The epidermis functions as a shield to protect your body from harmful UV rays, pathogens (bacteria, viruses, fungus, and parasites), and chemicals.
Location: The epidermis is the top layer (skin)