Anatomy - Dermatology

cuticle

extension of stratum corneum of the epidermis over the base of nail

subserous fascia

fascia between musculoskeletal walls & serous membranes

investing fascia

fascia of invester muscles & nerves

albinism

a genetic defect in which you lack tyrosinase

bursae

fluid containing sacs

stratum lucidum

*found only in thick skin*, consists of a thin, translucent layer of flattened eosinophilic keratinocytes held together by desmosomes

cancer basal cell carcinoma squamous cell carcinoma

1/3 originate from the skin basal layer = spinous layer =

pilosebaceous unit

A hair follicle and its associated sebaceous glands make up a...?

Subcutaneous layer

Consists of *loose connective tissue* with pads of *adipocytes*. Binds the skin loosely to the underlying tissues and corresponds to the superficial fascia of gross anatomy.

yes, but dark-skinned individuals produce melanin more rapidly and accumulate them more abundantly

Do dark and light skinned individuals have the same amount of melanocytes?

stratum basale

Epidermal region involved in rapid cell division; most inferior epidermal layer

increases

Exposure to UV light increases or decreases production of melanin?

asynchronous

Is hair growth and shedding synchronous or asynchronous?

eumelanin

Melanin that give brown and black color to hair

nail bed

Portion of the living skin that supports the nail plate as it grows toward the free edge.

palms and soles

Sebaceous glands are embedded in the dermis over most of the body, except in the..?

arrector pili

Smooth muscles whose contractions force hairs to stand erect

False, We have few or no melanocytes

T/F. We have a lot of melanocytes at the palmar or plantar region

Dermis

The deep layer of the skin; composed primarily of dense, irregular connective tissue. *collagen* It also has loose connective tissue

hyponychium

The distal end of the plate becomes free of the nail bed at the epidermal fold called the...?

lubricate skin and hair

The function of sebaceous glands is to..?

nail body

The part of the nail that is visible. appears pink due to underlying blood capillaries.

nail root

The proximal part of the nail. Forms from the nail matrix in which cells divide, move distally, and become keratinized in a process somewhat similar to hair formation but without keratohyaline granules.

lamellated corpuscles

The receptors for deep pressure and high frequency in the dermis and subcutaneous tissue are ___.

nail plate

extends past finger or nail body

hair follicle

Tubelike depression in the skin in which a hair develops

anagen, catagen, and telogen

What are the three phases of hair growth?

retinoids

What class of acne medications can reduce sebaceous gland activity thereby reducing the formation of keratinized plugs?

melanocytes located in the hair bulb

What determines hair color?

stratum lucideum

What layer is missing from thin skin?

underneath

Where is the arrector pili muscle in relation to the sebaceous gland?

dermis layer, mostly damage of collagen fibers

Which skin layer are stretch marks found in?

intermuscular septa

_____ _____ are very thick fascia that separate one muscle group from another

sebum

a complex mixture of lipids that includes wax esters, squalene, cholesterol, and triglycerides that are hydrolyzed by bacterial enzymes after secretion. *Increases greatly at puberty*, stimulated primarily by testosterone in men and by ovarian and adrenal androgens in women

root hair plexuses

a web of sensory fibers surrounding the bases of hair follicles in the reticular dermis that detects movements of the hairs

tyrosinase

ability to synthesize melanin is dependent on the ability of melanocytes to produce what enzyme?

basement membrane

always occurs between the stratum basale and the dermis, and follows the contour of the interdigitations between these layers.

Carotene

an orange or red plant pigment found in carrots and many other plant structures. Precursor to vitamin A

five stratum layers

basal, spinosum, granulosum, lucidum, corneum

nail plate

bound to a bed of epidermis, the nail bed, which contains only the basal and spinous epidermal layers.

catagen

brief period of arrested growth and regression of the hair bulb?

langerhan's cells

cells found in the epidermis that are APCs.

hair papilla

connective tissue and a capillary loop that nourishes the hair follicle

stratum granulosum

consists of three to five layers of flattened cells, now undergoing the *terminal differentiation process* of keratinization.

lunula

crescent-shaped white area. mixture of opaque nail matrix and immature nail plate

Melanin

dark brown pigment in the skin that helps protect the skin by absorbing ultraviolet rays

deep fascia

dense, organized CT layers. DEEP to the skin. investing fascia, intermuscular septa, and subserous fascia

free edge

distal end of nail plate. the epidermal fold is underneath it.

hair

elongated keratinized structures that form within epidermal invaginations, the hair follicles

meissner's corpuscles

found in the papillary layer of the dermis and activated by light touch. also called tactile corpuscles.

papillary layer

free nerve endings, tactile receptors (meissner's corpuscles), and capillary loops are in what layer of the dermis?

third degree burn

full thickness burn and may ulcer and require skin grafting

nail matrix

germinal region of the nail plate

reticular layer

hair follicles, sudiferous glands, sebaceous glands, and sensory nerve endings are present in which layer of the dermis?

anagen

hair growth phase? long period of mitotic activity and growth

free nerve endings

in the papillary dermis and extending into lower epidermal layers, which respond primarily to high and low temperatures, pain, and itching, but also function as tactile receptors

Papillary layer

includes the dermal papillae, consists of loose (areolar) connective tissue, with types I and III collagen fibers, fibroblasts and scattered mast cells, dendritic cells, and leukocytes

epidermal ridges

increase friction, provide better gripping surface, causes fingerprints. caused by epidermis invaginating into the dermis *between the dermal papillae*

psoriasis

increased keratinization/thickening of the epidermis due to overactive T lymphocytes which triggers autoimmune reaction to the skin

four different layers of the epidermis

keratinocytes, melanocytes, merkel's cells, langerhan's cells

basal layer

location of melanocytes

telogen

long period of inactivity during which hair must be shed

friction blister

lymph filled space between the epidermis and the dermis of the thick skin. created by excessive rubbing of ill-fitting shoes

eponychium

medical term for cuticle

ceruminous glands

modified APOCRINE glands in external auditory canal that secrete ear wax to prevent foreign bodies from entering the ear

reticular layer

much thicker, consists of dense irregular connective tissue (mainly bundles of type I collagen), with more fibers and fewer cells than the other layer of the dermis

stratum corneum

outermost layer of the epidermis, which consists of flattened, *keratinized cells*. These fully keratinized or cornified cells called squames are *continuously shed at the epidermal surface* as the desmosomes and lipid-rich cell envelopes break down

nail root

portion buried in fold of skin at base of the nail. as it hardens it becomes the nail plate

fascial planes

potential spaces between adjacent fascias or fascia-lined structures

corns and calluses

protective thickening/hardening of the cornified epidermal layers, can occur with continued rubbing

light-skinned and sun exposure

risk factors for skin cancer

first degree burn

superficial burn in which the epidermis is injured

second degree burn

superficial, partial-thickness burn. may blister and can take weeks to heal and scar.

eccrine sweat glands

sweat glands that empty their secretion onto the skin surface via sweat pores

apocrine sweat glands

sweat glands that secrete a more protein-rich sweat into the follicles of hair in skin of the axillae and perineum

merkel's cells

tactile cells -sensory receptors for fine pressure (ex blowing air onto arm)

line of cleavage

tension lines that show predominant orientation of collagen fiber bundles

subQ, subfascial, and subtendinous

types of bursae

stratum spinosum

typically the thickest layer of keratinocytes. They are held together by desmosomes

holds tendons in place during movement

what do retinacula do?

stratum corneum and fatty areas of dermis and hypodermis

where is vitamin A found

increased UV radiation, they don't produce as much melanin

why is melanoma more predominant in lighter skinned individuals

translucent

without melanin and carotene the skin appears...?