The Integumentary System Flashcards
What are the functions of the integumentary system?
Protection
Excretion (eliminating or expelling waste)
Cutaneous sensation (a sensation (as of warmth, cold, contact, or pain) aroused by stimulation of end organs in the skin)
Vitamin D synthesis
Blood reservoir
Thermoregulation
Name the two layers of the skin?
dermis and epidermis
What is the hypodermis? Where is it located?
Lies deep to the dermis (third and final layer)
What are the primary tissue types in the hypodermis?
areolar and adipose CT
Describe the 3 function(s) of the hypodermis.
- Anchors the skin to underlying organs
- Acts as a shock absorber and insulates the deeper body tissues
- Contains the major blood vessels that supply the skin
What 4 types of cells are found in the epidermis and what are their functions? Which of these is the primary cell type?
keratinocytes (primary cells) - produce keratin
melanocytes - produce melanin
langerhans cells - protect against bacterial invasion
Merkel cells - sensory receptors for touch
What is the function of keratin? melanin?
Keratin - helps forms hair, nails and the outer layer of the skin , water resistant
melanin- skin pigmentation can either be brown-black or pink-red
UV ray protection
What are the fiver layers of the epidermis?
From top to bottom (deep to superficial, they all start with STRATUM)
Stratum BASALE Stratum SPINOSUM Stratum GRANULOSUM Stratum LUCIDUM (only in thick skin) Stratum CORNEUM
How do the five layers of the epidermis differ in function & appearance?
Stratum BASALE - where the cells divide and the daughter cell gets pushed in to the cell layer above to begin its specialization into mature keratinocyte
Stratum SPINOSUM - (contains thick bundles of intermediate filaments which consist of tension-resisting protein (pre-keratin) last layer that mitosis occurs
Stratum GRANULOSUM- makes granules : the process of keratinization begins (in which the cells fill with keratin) , lamella granules (contain glycolipds that slow water loss across the epidermis.)
Stratum LUCIDUM (only in thick skin)- Consists of few rows of flat, dead keratinocytes.
Stratum CORNEUM - Keratin the the plasma membrane protects skin against abrasion and penetration
IN LAME MAN TERMS: the process of making keratin
Stratum BASALE - make new cells
Stratum SPINOSUM - pre-keratin
Stratum GRANULOSUM - keratinization starts
Stratum LUCIDUM (only in thick skin) - dead keratin
Stratum CORNEUM - mature keratin
How do the five layers of the epidermis differ in appearance?
Stratum BASALE - single row of stem cells
Stratum SPINOSUM- several cell layers , has spikelike extensions of its keratinocytes unified by desmosomes
Stratum GRANULOSUM - one - five layers ; flattened cells, grainy apprance, their nuclei and organelles begin to disintegrate and they accumulate two types of granules.
Stratum LUCIDUM (only in thick skin)- thin translucent band
Stratum CORNEUM - flattened, anucleate cells , 20 to 30 layers of cells thick (3/4 of the epidermal thickness)
What layer is not present in thin skin?
Stratum LUCIDUM
Generally describe the process through which epidermis is renewed and maintained.
the whole basale to corner thing
In which layer do cells contain keratohyalin and lamellar granules? What is the
functional significance of each of these granule types?
Stratum Granulosum;
keratohyalin granules- the process of keratinization begins (in which the cells fill with keratin)
lamella granules - (contain glycolipds that slow water loss across the epidermis.)
In which epidermal layer do the keratinocytes take on a spiny appearance?
Stratum Spinosum
In which epidermal layer do tonofilaments (bundle of intermediate filaments within a cell) first become evident?
Stratum Spinosum
Which layer contains most of the melanocytes?
Stratum Basale
In which layer do the cells begin to die? Why do they die?
Stratum Granulosum ; due to lack of nutrients
In what body areas is thick skin located?
Stratum Lucidum
What is the primary tissue type in the dermis? What type of connective tissue fibers
does it contain? What types of cells are commonly found in the dermal layer?
Areolar and Adipose ; Elastic fibers, reticular fibers, and collagen fibers ; fibroblasts, macrophages, occasional mast cells and WBC
sac
sds
What organs/structures are located in the dermis?
The dermis contains nerve endings, sweat glands and oil glands (sebaceous glands), hair follicles, and blood vessels, cleavage lines, dermal papillae
What are the layers of the dermis? Which of these two layers is more superficial?
Papillary and Reticular ; Papillary is more superficial
Which dermal layer is composed primarily of areolar connective tissue? which of dense
irregular connective tissue?
Areolar - Papillary tissue ;
Dense irregular CT - Reticular
What is the significance of the dermal papilla? of the epidermal ridges?
Dermal papilla - blood vessels in this nourish all hair follicles and bring nutrients and oxygen to the lower layers of the epidermal cells
Epidermal ridges - Enhances our ability to grip certain kinds of surfaces (on plasma of hands and soles of your feet, makes fingerprints)
What forms the lines of cleavage?
Collagen fibers
What is the cause of pressure injuries?
Results from loss of or restricted blood flow to the tissue
What pigments determine skin color?
Melanin - melanocytes
How does sunlight affect melanocytes?
Causes a substantial melanin buildup which helps protect the DNA of skin cells from UV radiation by absorbing the rays and dissipating the energy as heat.
What effects does chronic exposure to UV radiation have on the skin?
It causes elastic fibers to climb which results in leathery skin which temporarily depresses the immune system and alters the DNA of skin cells and leads to skin cancer.
The inherited condition of albinism is most often associated with an inability to
synthesize what enzyme? What is the direct effect of a deficiency of this enzyme?
Tyrosinase ; it catalyzes the first 2 steps of melanin pigmentation biosynthesis
Distinguish between the root and shaft of an individual hair.
Root - the part embedded in the skin
Shaft - The part that projects above the skins surface
Describe the location and function of the hair follicle itself, the papilla and matrix of the follicle, the root hair plexus, and the arector pili muscle.
AAA
What causes arrector pili contraction?
Cold temperatures or fear causes the muscle to pull the hair follicle upright and dimples the skin producing goose bumps
What are the two basic types of glands in the integumentary system?
Apcrine and Eccrine sweat glands
Describe the structure and function of sebaceous glands.
Exocrine gland that usually attached to hair follicles and release a fatty substance, sebum, into the follicular duct and thence to the surface of the skin.
Describe the structure and function of sebaceous glands.
Simple branched alveolar glands, found everywhere but plams and soles of feet
Exocrine gland that usually attached to hair follicles and release a fatty substance, sebum, into the follicular duct and thence to the surface of the skin.
They become go engorged that they burst (holocrine glands)
Describe the composition and functions of sebum.
Accumulated lipids and cell fragments
Soften and lubricates hair and skin, prevents hair from becoming brittle, and slows water loss from skin.
Where do the ducts of most sebaceous glands terminate?
Into their follicle
What are the two main types of sudoriferous glands (sweat glands) associated with the skin?
Eccrine Sweat Glands & Apocrine Sweat Glands
BOTH COILED TUBULAR SWEAT GLANDS
Describe the secretions produced by each of the eccrine and apocrine glands?
sweat = 99% water, some salts, traces of metabolic wastes and microbe killing peptide called (dermcidin)
To what functional class does eccrine and apocrine glands fall under?
exocrine glands
Which type of sudoriferous gland secretes into hair follicles? into ducts that open in a pore on the skin’s surface?
Apocrine ; Eccrine
What are the differences between basal cell carcinoma, squamous cell carcinoma, and melanoma?
Basal cell carcinoma - least malignant and most common, the basal cells proliferate (increase rapidly), invading the dermis and subcutaneous tissue, appear shiny and dome shaped
Squamous cell carcinoma - second most common, arises from the keratinocytes in the Stratum Spinosum, scaly reddened pauple
Melanoma - Most dangerous , 1% of cancers , brown to black patch, metastizes rapidly to surrounding lymph and blood vessels
The ABCDE mnemonic is a way to remember the key detection points of melanoma. What does each letter of the mnemonic represent?
Asymmetry - the two sides of the pigmented spot or mole do not match
Border irregularity - The borders of the lesion exhibit indentations
Color- The pigmented spa contains several color (black, browns, tans, and sometimes blues and reds)
Diameter - spot is larger than 6 mm in diameter (size of pencil eraser)
Evolution (changes with time)
What is a burn?
a damage inflicted by intense heat, electricity, radiation, or certain chemicals, all of which kill cells in the affected areas
Identify the 3 classes of burns. Describe the general characteristics of each class.
first, second, third degree
first - only epidermis is damaged (localized redness, sweating and pain.) two-three days to heal
second - epidermis and upper region of the dermis (red and painful but little to no scarring) three to four weeks healing
third -entire thickness of the skin (appears gray-white, cheery red or blackened, nerve ending destroyed, burned area is not painful) skin grafting is advised.
Which of the above class(es) is/are considered partial-thickness? full-thickness?
partial - first , second
full - third
What are the potential life-threatening systemic effects of severe burns?
Infection and sepsis become the main threat become body is exposed , main cause of death (multiply rapidly in dead tissue.)
Determine key anatomical areas to assess for a pressure injury.
Bony prominences
knees elbow, ear, coxal, tailbone etc
Identify patients at risk for pressure injuries.
Immobile patients are vulnerable
Describe the progressive stages of pressure injuries.
Stage 1 - skin is unbroken but inflamed
Stage 2 - Skin is broken to epidermis or dermis
Stage 3- Ulcer extends to subcutaneous fat layer
Stage 4 - Ulcer extends to muscle or bone
How does the Braden Scale assess for a pressure injury?
The scale is composed of six subscales that reflect sensory perception, skin moisture, activity, mobility, friction and shear, and nutritional status.
everything is on a scale of 1-4 ,
19 to 23 (Not a risk) 15 to 18 (Mild risk) 13 to 14 (Moderate risk) 10 to 12 (High risk) 9 or lower (Very High Risk)
What would you document if you detect a pressure injury?
Do describe what you see: type of wound, location, size, stage or depth, color, tissue type, exudate, erythema, condition of periwound. Don’t guess at the type or the stage of a pressure ulcer or injury (hereafter, pressure injury [PI]) or the depth of the wound.
In what epidermal layer do you first expect to see significant amounts of keratin (rather than pre-keratin?)
STRATUM Granulosum
