Chapter 5: Integumentary System Flashcards
basic facts about skin
- cutaneous membrane
- 16% of total body weight
- fist accessory structures
What are the 6 functions of the skin?
- Protection
- Excretion
- Production
- Synthesis
- Storage
- Sensation
against invading pathogens
Protection
salts, water, and inorganic wastes
Excretion
different proteins (melanin, keratin)
Production
vitamin D
Synthesis
temporary storage of fats
Storage
detections of touch, pressure, pain, etc.
Sensation
3 cells of epidermis
- Keratinocytes
- Melanocytes and langerhans
- Avascular
a tough fibrous protein that also forms the structural component of hairs and nails
Keratinocytes
contains 4 layers of keratinocytes
Thin skin
contains 5 layers (found in palms and sole)
Thick skin
5 layers of epidermis
- Stratum corneum
- Stratum lucidum
- Stratum grabulosum
- Stratum spinosum
- Stratum basale (Germinativum)
- Exposed surfaces of both thick and thin skin
- 15 to 30 layers of keratinocytes
- Excessive sloughing from the surface is called dandruff
Stratum corneum
thick skin of palm and soles
Stratum lucidum
3 to 5 layers derived from stratum spinosum
Stratum grabulosum
8 to 10 spiny layers that contains densritic cells
stratum spinosum
- deepest layer
- forms the epidermal ridges
Stratum basale (germinativum)
in skin subjected to friction, number of layers in the stratum cirneum greatly increases, producing a thickened area
callus
- lies between the epidermis and sucutaneous layer
- contains the accessory structure
- contains network of blood vessels and nerve fibers
Dermis
2 layers of dermis
- Papillary layer
- Reticular layer
- consists of areolar tissue
Contains: - capillaries
- lymphatic vessels
- sensory nerve fibers that supply the surface of the skin
Papillary layer
- consists of dense irregular connective tissue
Contains: - collagen (strong and resist stretching)
- elastic fiber (permits stretching)
Reticular layer
3 Accessory structures
Hair
Nails
Glands
Keratinous filament growingg out of the epidermis
Hair
Originates in an epidermal penetration of the dermis called_______
Hair follicle
Hair texture (straight, curly) is determined by the shape and strcuture of the _______
Cortex and medulla
What are the 7 parts of the nail?
- Free edge
- Nail plate
- Hyponychium
- Nail bed
- Lunula
- Cuticle
- Matrix
the end portion of the nail
Free edge
visible portion that rest on the nail bed
Nail plate
skin under the free edge
Hyponychium
portion of the skin where nail plates rests
Nail bed
seen as a half-moon located at base of nail
Lunula
overlapping skin at the base of the nails
Cuticle
where new cells formed
Matrix
3 types of glands
- Sudoriferous glands (sweat glands)
- Sebaceous glands
- Ceraminous glands
2 types of sweat glands
- Eccrine sweat glands
- Aprocrine sweat glands
- found in every region of the skin
- produce secretion of water and sodium chloride
Eccrine sweat glands
Found in axillary and pubic regions
Apocrine sweat glands
produce an oily secretion known as sebum, carried through ducts to the surface of the skin or to hair follicles
Sebaceous glands
- Found only in the dermis of the ear canals
- Produce a waxy secretion known as cerumen to protect the ear canals and lubricate the eardrum
Ceruminous glands
• Also known as cornification
• Process of keratin accumulating within keratinocytes
• Begin their life as offspring of the stem cells of the stratum basale
Keratinization
• Being the body’s outmost organ, the skin is able to regulate the body’s temperature by controlling how the body interacts with its environment
Temperature homeostasis
secreted to control body temperature
- Sweat
- Vasodilation
- Vasoconstriction
• An essential vitamin necessary for the absorption of calcium from food, is produced by ultraviolet (UV) light striking the skin
- Sterol molecule known as 7-dehydrocholesterol to calcitriol
Vitamin D
• Minor mechanical damage from rough or sharp objects is mostly absorbed by the skin before it can damage the underlying tissues
Protection
3 pigments of skin color
- Melanin
- Carotene
- Hemoglobin
Brown or black pigment produced by melanocytes to protect skin from UV radiation
melanin
yellow or orange cast
Carotene
red pigment found in red blood cells
Hemoglobin
• Skin allows the body to sense its external environment by picking up signals for touch, pressure, vibration, temperature, and pain
Cutaneous sensation
6 common integumentary diseases
- Contact dermatitis
- Blisters
- Skin cancer (melanoma)
- Skin infections (cellulitis)
- Skin rashes (dry skin)
- Skin disorders (acne, eczema, psoriasis)
over a bony prominence, the stratum corneum can thicken to form a cone-shaped structure
Corn
skin is overstretched
Stretch marks
upper part of the dermis which extend toward the spidermis
dermal papillae
Drawing the skin taut and inserting a small needle at a shallow angle into the dermis; tuberculin test
Intradermal injection
pinching the skin to form a tent and inserting a short needle into the adipose tissue of the subcutaneous tissue; insulin injection
Subcutaneous injection
Inserting a long needle at a 90-degree angle to the skin into a muscle deep to the subcutaneous tissue; used for vaccines and certain antibiotics
Intramuscular injection
- produces melanin
- determined by genetic factors, exposure to light, and hormones
Melanocytes
- within melanocytes
- golgi apparatuses package melanin into vesicles
melanosomes
recessive genetic trait that causes a deficiency or an absence of melain
- fair skin, white hair, unpigmented irises in the eyes
Albinism
Decrease in the blood o2 content produces a bluish color of the skin
Cyanosis
yellowish skin color
- liver is damaged by a disease such as viral hepatitis
Jaundice
- injury to a tissue caused by heat, cold, friction, chemicals, elextricity, or radiation
Burn
- part of the stratum basale remains viable, regeneration of the epidermis occurs from within the burn area, as well as from the edges of the burn
Partial-thickness burns
- only the epidermis are red and painful
- slight edema or swelling may be present
- caused by sunburn or brief exposure to very hot or very cold objects
- heal without scarring in about a week
first-degree burns
- damages both the epidermis and the dermis
- If dermal damage is minimal – redness, pain, edema, and blisters
- Healing = 2 weeks, no scarring results
- If the burn goes deep into the dermis – wound appears red, tan, or white
- Heal = take several months
- Might scar
- Epidermis, including the stratum basale where stem cells are found, is damaged
Second-degree burns
- Appear white, tan, brown, black, or deep cherry red
- Take a long time to heal and form scar tissue with disfiguring and debilitating wound contracture
full-thickness/third-degree burns
most frequest type of cancer; begins with cells in the stratum basale and extends into the dermis to produce an open ulcer
Basal cell carcinoma
develops from cells immediately superficial to the stratum basale
Squamous cell carcinoma
- rare form of skincamcer that arises from melanocytes, usually in a preexisting mole
Malignant melanoma
- longer wave length- tanning of the skin
- development of malignant melanoma
UVA
- causes most burning of the skin
- development of basal cell and squamous cell carcinomas
UVB