skin appendages

Skin appendages

Hair, sebaceous gland, nail, eccrine and apocrine glands

Hair: *hair germ

* hair papilla
* hair bulb
Matrix melanocytes
* hair shaft

Medulla cortex cuticle









Types of hair
Lanugo hair: fine and long. Shed before birth
Vellus hair: fine and short. Replace lanugo
Terminal hair: long coarse. Scalp, mustache
---Arrector pili

Hair cycle
Anagen: grow- 3 years
Catagen: involution- 3 weeks
Telogen: resting- 3 months

Sebaceous gland

*multlobed, assoc. with hair.
* ectopic: Meibomian gl.---eyelid
Tyson’s gl.----prepuce
Fordyce spots----buccal mucosa
Montgomery's gl.---- areola
Sebum( TG, ch.esters, phos. Lip. and squalene)
Lubricant, bacterio and fungistatic


Nail
Nail plate- hard keratin
Nail folds
Nail matrix
Cuticle
Nail bed

Eccrine gl.

Coiled secretary portion and duct
Cholinergic stimulation
Thermoregulation
Thermal, emotional and gustatory
Sweat: Na, KCL, lactate, urea, ammonia

Apocrine gl.

Coiled sec. portion and duct
Axilla, nipple, periumbilical and genitalia
Adrenergic stimuli
Unknown function
Protein, CHO, lipid and
ammonia

Primary skin lesions

Macule: flat discoloration <0.5 cm ex. Freckle
Patch: flat discoloration >0.5 cm ex. Vitiligo
Papule: superficial elevation <0.5cm ex. Wart
Plaque: superficial elevation >0.5cm ex. Psor.
Nodule: circumscribed elevation with depth ex. leish.
Vesicle: circum. elevation contain fluid<0.5 cm ex. Herpes
Bulla: circum. elevation contain fluid >0.5cm-B.pemph.

Primary skin lesions

Wheal: evanescent edematous elevation<24 h—urt.
Petechiae: pinhead size blood depsits
Purpura: larger macules and papulues of blood
Pustules: small elevation contain pus-- folliculitis

Secondary skin lesions

Scales: excess dead epidermal cells.—psor.
Crust: dried blood or tissue fluid—impetigo
Erosion: loss of epidermis, heals without scar
Ulcer: loss of epidermis and part of dermis, heals with scar.
Excoriation: scratch marks
Scar: new connective tissue
Atrophy: thinning of epi., derm., fat.
Lichenification: thickening of skin


Pathological terms
Acanthosis: hyperplasia of prickle.—psor.
Hyperkeratosis: thick. Of str. Corneum
Hypergranulosis: thick. Of gran. Layer—lichen planus
Acantholysis: loss of cohesion bet. Kerat. Intraepidermal vesicle.---pemphigus
Parakeratosis: retention of nuclei in str. Corn.– psor.
Spongiosis: intercellu. Edema---dermatitis
Dyskeratosis: premature keratin. ---SCC

Exocytosis: migration of inflamm. Cells

Liquefaction degeneration:degen. Of basal layer
Balloon degeneration: intracell. edema loss of bridges and edema

macules

patch
papule
bulla
vesicle
plaque

examples

pustule

crust
lichenification