Integumentary System Flashcards
also known as the cutaneous membrane and covers the external surface of the body
skin
the skin consists of two main part
epidermis and dermis
the superficial thinner portion which is composed of epithelial tissue (avascular = does not bleed)
epidermis
the deeper thicker connective tissue portion of the skin (vascular = bleeds)
dermis
deep to the dermis, but not part of the skin consists of areolar and adipose tissue which serves as a storage depot for fat and large blood vessels
subcutaneous layer/ hypodermis
the nerve endings that are present in the skin are called
lamellated corpuscles
the four principal types of cells in the epidermis
keratinocytes, melanocytes, intraepidermal macrophages (Langerhan cells), tactile epithelial cells (Merkel cells)
tough fibrous protein that helps protect the skin from abrasions, heat microbes and chemicals
keratinocytes
produces melanin that contributes to skin color and absorbs damaging UV light
melanocytes
they participate in immune responses mounted against microbes that invade the skin and help other cells recognize an invading microbe
Langerhan cells/ intraepidermal macrophages
located in the deepest layer of the epidermis detect touch sensation
Merkel cells/ Tactile epithelial cells
five layers of the epidermis
stratum basale stratum spinosum stratum granulosum stratum lucidum stratum corneum
“germinating layer” the deepest layer of the epidermis, composed of stem cells that continuously undergo cell division, simple columnal/ cuboidal cells
stratum basale
“prickly layer” 8 to 10 layers of keratinocytes, provides strength and flexibility to the skin
stratum spinosum
“granular layer” stratified squamous cells undergoing apoptosis, marks the transition between metabolically active strata and dead cells of the more superficial strata
stratum granulosum
“clear layer” present only in thick skin and composed of dead keratinocytes
stratum lucidum
“horny layer” 20-30 layers of continuously replaced anucleated keratinocytes
stratum corneum
two layers of the dermis
papillary and reticular
the thin superficial layer made up of areolar connective tissue where dermal paillar that contain free nerve endings and touch receptors are licated
papillary layer
deeper layer of the dermis made up of coarse, dense irregular connective tissue
reticular tissue
two main regions of the hair
shaft and root
three concentric layers of the keratinized cells in the hair
medulla, cortex and cuticle
plates of tightly packed, hard, dead, keratinized cells
nails
two types of sweat glands
eccrine and apocrine
simple coiled tubular sweat glands that are abundant on the palms, soles of the feet, and forehead and help control body temperature
eccrine
sweat glands confined chiefly in the axilliary and genital regions and usually open into hair follicles
apocrine
modified apocrine glands that form cerumen or earwax
ceruminous glands
other name for sweat glands
sudoriferous glands
simple branched alveolar glands present on all skin surfaces except in the thick skin of the palms and soles that secrete oil/fatty substance called sebum with bactericidal properties
oil glands/ sebacious glands
bluish discoloration of the skin due to decreased levels of hemoglobin
cyanosis
refers to a change in skin color during episodes of fear, anger or emotional stress or may signify anemia or low BP
pallor or blanching
abnormal yellow skin tone which usually signifies a liver disorder where normally secreted bile pigments accumulate in the blood
jaundice
flat and small (<1cm) skin lesion
seen in maliganant melanomas and fungal infection
macule
flat and large (>1cm) skin lesion
seen in seborrhaic dermatitis and vitiligo
patch
small (<1cm) raised spot
seen in skin tags and basal cell carcinoma
papule
large (>1cm) raised spot
commonly seen in psoriasis and atopic dermatitis
plaque
raised, fluid filled and small (<1cm)
seen in herpes simplex virus and contact dermatitis from poison ivy
vesicle
raised, fluid filled and large (>1cm)
seen in insect bites
bulla
three major forms of skin cancer
basal cell carcinoma, squamous cell carcinoma, and melanoma
ABCDE of melanoma
asymmetry border color diameter evolution
classification of burns according to severity
first degree burns epidermis only damaged
second degree burns dermis damaged
third degree burns subcutaneous layer
burns are considered critical when:
25 % of the body has second degree burns
10 % of the body has third degree burns
third degree burns on the face, hand, and feet
