- acne
- skin condition due to infected sebaceous glands
- albinism
- genetic disorder that affects the skin, in which there is no melanin production
- anagen
- active phase of the hair growth cycle
- apocrine sweat gland
- type of sweat gland that is associated with hair follicles in the armpits and genital regions
- arrector pili
- smooth muscle that is activated in response to external stimuli that pull on hair follicles and make the hair “stand up”
- basal cell carcinoma
- cancer that originates from basal cells in the epidermis of the skin
- basal cell
- type of stem cell found in the stratum basale and in the hair matrix that continually undergoes cell division, producing the keratinocytes of the epidermis
- bedsore
- sore on the skin that develops when regions of the body start necrotizing due to constant pressure and lack of blood supply; also called decubitis ulcers
- callus
- thickened area of skin that arises due to constant abrasion
- catagen
- transitional phase marking the end of the anagen phase of the hair growth cycle
- corn
- type of callus that is named for its shape and the elliptical motion of the abrasive force
- cortex
- in hair, the second or middle layer of keratinocytes originating from the hair matrix, as seen in a cross-section of the hair bulb
- cuticle
- in hair, the outermost layer of keratinocytes originating from the hair matrix, as seen in a cross-section of the hair bulb
- dermal papilla
- (plural = dermal papillae) extension of the papillary layer of the dermis that increases surface contact between the epidermis and dermis
- dermis
- layer of skin between the epidermis and hypodermis, composed mainly of connective tissue and containing blood vessels, hair follicles, sweat glands, and other structures
- desmosome
- structure that forms an impermeable junction between cells
- eccrine sweat gland
- type of sweat gland that is common throughout the skin surface; it produces a hypotonic sweat for thermoregulation
- eczema
- skin condition due to an allergic reaction, which resembles a rash
- elastin fibers
- fibers made of the protein elastin that increase the elasticity of the dermis
- eleiden
- clear protein-bound lipid found in the stratum lucidum that is derived from keratohyalin and helps to prevent water loss
- epidermis
- outermost tissue layer of the skin
- eponychium
- nail fold that meets the proximal end of the nail body, also called the cuticle
- external root sheath
- outer layer of the hair follicle that is an extension of the epidermis, which encloses the hair root
- first-degree burn
- superficial burn that injures only the epidermis
- fourth-degree burn
- burn in which full thickness of the skin and underlying muscle and bone is damaged
- glassy membrane
- layer of connective tissue that surrounds the base of the hair follicle, connecting it to the dermis
- hair bulb
- structure at the base of the hair root that surrounds the dermal papilla
- hair follicle
- cavity or sac from which hair originates
- hair matrix
- layer of basal cells from which a strand of hair grows
- hair papilla
- mass of connective tissue, blood capillaries, and nerve endings at the base of the hair follicle
- hair root
- part of hair that is below the epidermis anchored to the follicle
- hair shaft
- part of hair that is above the epidermis but is not anchored to the follicle
- hair
- keratinous filament growing out of the epidermis
- hypodermis
- connective tissue connecting the integument to the underlying bone and muscle
- hyponychium
- thickened layer of stratum corneum that lies below the free edge of the nail
- integumentary system
- skin and its accessory structures
- internal root sheath
- innermost layer of keratinocytes in the hair follicle that surround the hair root up to the hair shaft
- keloid
- type of scar that has layers raised above the skin surface
- keratin
- type of structural protein that gives skin, hair, and nails its hard, water-resistant properties
- keratinocyte
- cell that produces keratin and is the most predominant type of cell found in the epidermis
- keratohyalin
- granulated protein found in the stratum granulosum
- Langerhans cell
- specialized dendritic cell found in the stratum spinosum that functions as a macrophage
- lunula
- basal part of the nail body that consists of a crescent-shaped layer of thick epithelium
- Meissner corpuscle
- (also, tactile corpuscle) receptor in the skin that responds to light touch
- Merkel cell
- receptor cell in the stratum basale of the epidermis that responds to the sense of touch
- medulla
- in hair, the innermost layer of keratinocytes originating from the hair matrix
- melanin
- pigment that determines the color of hair and skin
- melanocyte
- cell found in the stratum basale of the epidermis that produces the pigment melanin
- melanoma
- type of skin cancer that originates from the melanocytes of the skin
- melanosome
- intercellular vesicle that transfers melanin from melanocytes into keratinocytes of the epidermis
- metastasis
- spread of cancer cells from a source to other parts of the body
- nail bed
- layer of epidermis upon which the nail body forms
- nail body
- main keratinous plate that forms the nail
- nail cuticle
- fold of epithelium that extends over the nail bed, also called the eponychium
- nail fold
- fold of epithelium at that extend over the sides of the nail body, holding it in place
- nail root
- part of the nail that is lodged deep in the epidermis from which the nail grows
- Pacinian corpuscle
- (also, lamellated corpuscle) receptor in the skin that responds to vibration
- papillary layer
- superficial layer of the dermis, made of loose, areolar connective tissue
- reticular layer
- deeper layer of the dermis; it has a reticulated appearance due to the presence of abundant collagen and elastin fibers
- rickets
- disease in children caused by vitamin D deficiency, which leads to the weakening of bones
- scar
- collagen-rich skin formed after the process of wound healing that is different from normal skin
- sebaceous gland
- type of oil gland found in the dermis all over the body and helps to lubricate and waterproof the skin and hair by secreting sebum
- sebum
- oily substance that is composed of a mixture of lipids that lubricates the skin and hair
- second-degree burn
- partial-thickness burn that injures the epidermis and a portion of the dermis
- squamous cell carcinoma
- type of skin cancer that originates from the stratum spinosum of the epidermis
- stratum basale
- deepest layer of the epidermis, made of epidermal stem cells
- stratum corneum
- most superficial layer of the epidermis
- stratum granulosum
- layer of the epidermis superficial to the stratum spinosum
- stratum lucidum
- layer of the epidermis between the stratum granulosum and stratum corneum, found only in thick skin covering the palms, soles of the feet, and digits
- stratum spinosum
- layer of the epidermis superficial to the stratum basale, characterized by the presence of desmosomes
- stretch mark
- mark formed on the skin due to a sudden growth spurt and expansion of the dermis beyond its elastic limits
- sudoriferous gland
- sweat gland
- telogen
- resting phase of the hair growth cycle initiated with catagen and terminated by the beginning of a new anagen phase of hair growth
- third-degree burn
- burn that penetrates and destroys the full thickness of the skin (epidermis and dermis)
- vitamin D
- compound that aids absorption of calcium and phosphates in the intestine to improve bone health
- vitiligo
- skin condition in which melanocytes in certain areas lose the ability to produce melanin, possibly due an autoimmune reaction that leads to loss of color in patches
Candela Citations
CC licensed content, Shared previously
- Chapter 5. Authored by: OpenStax College. Provided by: Rice University. Located at: http://openstaxcollege.org/files/textbook_version/low_res_pdf/13/col11496-lr.pdf. Project: Anatomy & Physiology. License: CC BY: Attribution. License Terms: Download for free at http://cnx.org/content/col11496/latest/.