7 Integumentary System Flashcards
What structures (in the body) are part of the integumentary system? (4)
- Skin
- hair
- glands
- nails
What does “integument” mean?
Covering
List the main functions of the integumentary system. (5)
- Protection
- Sensation
- Vitamin D production
- Temperature regulation
- Excretion
What are the sensory receptors in the integumentary system capable of detecting? (5)
- Heat
- cold
- touch
- pressure
- pain
How does the integumentary system provide protection? (7)
Given the structures:
- Melanin
- Skin
- Hair
- Eyebrows
- Eyelashes
- Nose/ear hair
- Skin lipids
- Melanin absorbs UV light.
- Blocks microorganisms and foreign substances.
- Hair insulates heat (head).
- Eyebrows block sweat from eyes.
- Eyelashes protect eyes from foreign objects.
- Nose/ear hair filters particles.
- Skin lipids reduce water loss.
Describe the process of Vitamin D production in the integumentary system. (5)
UV light → precursor molecule → blood to liver (modification) → kidneys (further modification) → active Vitamin D formation.
Why is vitamin D important?
helps regulate calcium and phosphorus levels
Maintaining body temperature within normal range despite environmental changes.
thermoregulation
List the four mechanisms of temperature regulation in the integumentary system. (4)
- Radiation (infrared energy)
- Convection (air movement)
- Conduction (direct contact with an object)
- Perspiration
How does the integumentary system contribute to excretion?
Small amounts of waste are lost through gland secretions in the skin.
What are the two major layers of the skin?
Epidermis and dermis
The most superficial layer of skin, made of epithelial tissue.
Epidermis
A layer of dense connective tissue below the epidermis.
Dermis
What does the skin rest on?
Subcutaneous tissue (not part of the skin), a layer of connective tissue.
What are the functions of the epidermis? (2)
- Prevents water loss
- resists abrasion.
What type of epithelium is the epidermis?
Keratinized stratified squamous epithelium.
What is the most superficial layer of the epidermis?
stratum corneum
What is found in the stratum corneum, and what is its role?
Dead squamous cells filled with keratin; keratin provides structural strength.
Cells in the deepest strata perform __, pushing older cells to the surface, where they flake off.
mitosis
How does cell movement in the epidermis occur? (5)
- New cells form by mitosis.
- Older cells are pushed to the surface.
- Cells change shape and chemical composition.
- Keratinization
- Outer layer of dead epithelial cells (resists abrasion and forms a permeability barrier)
Cells of the epidermis that are the body’s most abundant epithelial cells, containing large amounts of keratin, providing structural strength to the stratum corneum.
keratinocytes
The deepest layer of the epidermis, consisting of cuboidal or columnar cells that undergo mitotic division approximately every 19 days.
stratum basale
Cells in this layer have many desmosomes, giving them a spiny appearance.
stratum spinosum
A thin layer of cells in the epidermis.
stratum granulosum
A thin, clear layer of dead skin cells in the epidermis with a translucent appearance.
stratum lucidum
The outermost layer of the epidermis, consisting of 25+ layers of dead squamous cells filled with keratin and joined by desmosomes, surrounded by lipids.
stratum corneum
What type of tissue composes the dermis (1) and what does it contain (3)?
Dense collagenous connective tissue containing:
- fibroblasts
- adipocytes
- macrophages
What structures extend into the dermis? (5)
- Nerves
- hair follicles
- smooth muscles
- glands
- lymphatic vessels
What gives the dermis its structural strength and resistance to stretch? (2)
- Collagen fibers (oriented in many directions)
- elastic fibers
Dermis: Areas where collagen fibers are more aligned, making the skin more resistant to stretch; incisions parallel to these lines gap less and produce less scar tissue.
cleavage lines (or tension lines)
What happens if the dermis is overstretched?
lead to damage and the formation of stretch marks
Projections in the upper dermis containing blood vessels, forming ridges in the palms, soles, and digits that create fingerprints and footprints.
dermal papillae
Provides padding, insulation, and stores about half of the body’s lipids; contributes to appearance differences between sexes and individuals.
subcutaneous tissue (hypodermis)
What is the subcutaneous tissue (hypodermis) composed of?
Loose connective tissue, including adipose tissue.
What are the main factors that determine skin color? (3)
- Pigments in the skin
- Blood circulation through the skin
- Thickness of the stratum corneum
What are the two primary pigments in the skin? (2)
- Melanin
- carotene
A group of pigments, mainly brown to black, that determines skin, hair, and eye color and provides UV protection.
melanin
How is melanin produced, packaged, and transferred in the skin? (3)
- produced by melanocytes
- packaged into melanosomes
- transferred to epithelial cells through phagocytosis of melanocyte tips.
An orange-yellow, lipid-soluble pigment from plants (e.g., squash, carrots) that accumulates in the stratum corneum and adipocytes of the dermis and subcutaneous tissues.
Carotene
Where does carotene primarily accumulate after consumption? (2)
- In the stratum corneum
- in adipocytes of the dermis and subcutaneous tissue.
Where is hair not found on the body? (4)
- Palms
- soles
- parts of the genitalia
- distal segments of fingers and toes
What are the three main parts of a hair strand? (3)
- medulla
- cortex
- cuticle
the innermost layer of the hair shaft
medulla
It surrounds the medulla. Contains most of the hair’s pigment, melanin.
cortex
the outermost part of the hair that covers the cortex.
cuticle
The visible part of the hair that protrudes above the skin surface.
hair shaft
The base of the hair follicle that rests on the hair papilla.
hair bulb
A mass of connective tissue, nerve endings, and blood capillaries at the base of the hair follicle.
hair papilla
Smooth muscles that contract to cause goosebumps by raising the skin.
arrector pili muscles
What are the two major glands of the skin? (2)
- Sebaceous glands
- sweat glands
What do sebaceous glands produce?
sebum
What are the two types of sweat glands? (2)
- Eccrine sweat glands
- apocrine sweat glands.
Simple, coiled, tubular glands that release watery sweat by merocrine secretion directly onto the skin surface, especially on palms and soles.
eccrine sweat glands
Where are eccrine sweat glands most numerous?
palms and soles
Simple, coiled, tubular glands that produce a thick, sticky secretion rich in organic substances, opening into hair follicles in the armpits, nipples, and pubic region.
apocrine glands
When do apocrine sweat glands become active?
at puberty
What causes odor in apocrine gland areas?
Bacteria feeding on the nutrient-rich secretions.
Types of skin lesions given the definition:
1. circumscribed collection of fluid
2. circular flat discoloration
3. circular, elevated solid, lesion
4. circumscribed flat discoloration
5. superficial solid elevated
6. superficial solid flat topped lesion
7. vesicle containing puss (inflammatory cells)
8. circular collection of free fluid
- bulla
- macule
- nodule
- patch
- papule
- plaque
- pustule
- vesicle
Types of skin lesions given the definition:
1. edematous, transitory, plaque, may last few hours
2. epidermal thickening; consists of flakes of plates of compacted desquamated layers of stratum corneum
3. dried serum or exudate on skin
4. crack or split
5. linear erosion
6. loss of epidermis superficial; part or all of the epidermis has been lost
7. thickening of the epidermis seen with exaggeration of normal skin lines
8. thickening; permanent fibrotic changes that occur in the skin
- wheal
- scale
- crust
- fissure
- excoriation
- erosion
- lichenification
- scar
Composed of layers of dead stratum corneum cells with hard keratin.
nail
What is the nail composed of?
layers of dead stratum corneum cells with hard keratin.
The visible part of the nail.
nail body
The part of the nail covered by skin.
nail root
The skin covering the nail root.
cuticle (eponychium)
The crescent-shaped, visible part of the nail matrix.
lunula
How does nail growth differ from hair growth?
Nails grow continuously and do not have a resting stage.
Why is the integumentary system useful in diagnosis?
It is easily observed.
A bluish color of the skin caused by decreased blood oxygen, indicating circulatory or respiratory issues.
cyanosis
What does a yellowish skin color (jaundice) indicate?
Possible liver damage, such as from viral hepatitis.
What can rashes and skin lesions indicate?
They may be symptoms of internal health problems.
Effects of Aging on the Integumentary System (9)
- Thinning of the Epidermis.
- collagen amount in the dermis decreases
- Vitamin D3 production declines
- Blood supply to dermis is reduced
- Function of hair follicles decline
- Dermis thins and elastic fibers decreases
- Loss of adipose tissue
- Repair rate slows
- Skin is drier as sebaceous glands activity decreases.
What is the most common cancer?
skin cancer
What mainly causes skin cancer?
UV light exposure.
Who is more prone to skin cancer?
Fair-skinned people.
How can skin cancer be prevented? (2)
- limiting sun exposure
- using sunscreens that block UVA and UVB rays.
Rays for tanning and are associated with malignant melanomas.
UVA rays
Rays that causes sunburns
UVB rays
Cancer affecting cells in the stratum basale, removable by surgery.
basal cell carcinoma
Cancer affecting cells above the stratum basale; can be fatal.
squamous cell carcinoma
A rare, deadly cancer arising from melanocytes in a mole.
malignant melanoma
