Chapter 5 Integumentary System Flashcards
Functions of the Integumentary a System
- External protective covering
- Barrier to viruses and bacteria
- Regulation of body temperature
- Reduces dehydration
- Facilitates cutaneous sensation
- Maintain metabolic functions and blood reservoirs
What makes up the integumentary system?
Skin
Hair
Nails
Sweat and Oil Glands
The 2 Regions of the skin, and details:
- Epidermis: outermost protective shield of the body. Composed of epithelial cells. Not vascularized.
- Dermis: Makes up the bulk of the skin. Tough and leathery layer composed mostly of fibrous tissue. Vascularized.
Hypodermis (Superficial Fascia)
Subcutaneous layer deep to the two layers of skin. Composed mostly of adipose tissue. Mainly insulates, and anchors skin to underlying structures, but also helps protect the underlying organs.
The 4 Cells of the Epidermis:
1) Keratinocytes
2) Melanocytes
3) Dendritic(Langerhans Cells)
4) Tactile (Merkel) Cells
Cells of epidermis: #1 Keratinocytes
- Produce keratin, which helps give epidermis protective qualities.
- Connected by desmosomes.
- Surface for Stratum Basale
- Epidermal growth factor
- Keratin-filled plasma membranes that die and flake off at the skin’s surface
Cells of the epidermis: #2 Melanocytes
- Located in deepest layer of epidermis; stratum Basale.
- Spider-shaped, epithelial cells.
- Synthesize the pigment Melanin.
- Melanin accumulates at superficial site of cells, eventually reaching surface of the skin to protect against UV Radiation.
Cells of Epidermis: #3 Dendritic (Langerhans) Cells
- Surface from bone marrow and migrate to epidermis.
- Activators of the Immune System
- Ingest foreign substances
- Extend among surrounding keratinocytes to form a continuous network
Cells of the Epidermis: #4Tactile (Merkel) Cells
- Located in epidermal-dermal junction.
- Shaped like a spiked hemisphere
- Intimately associated with disc-like sensory nerve endings.
- Function as sensory receptors for touch.
The 5 Layers of the Epidermis:
Deep to Superficial
1) Stratum Basale
2) Stratum Spinosum
3) Stratum Granulosum
4) Stratum Corneum
5) Stratum Lucidium(only in palms of hands and soles of feet)
Layers of the Epidermis: #1 Stratum Basale
- Deepest Epidermal layer
- One row of actively mitotic stem cells
- Newly formed cells become part of the more superficial layers.
- See occasional melanocytes and dendritic cells.
Layers of the Epidermis: #2 Stratum Spinosum
- Several layers of keratinocytes unified by desmosomes.
- Cells contain thick bundles of intermediate filaments made of pre-keratin.
Layers of the Epidermis: #3 Stratum Granulosum
- Typically five layers of flattened cells, organelles deteriorating.
- It’s cytoplasm is full of lamellar granules (release lipids) and keratohyaline granules.
Layers of the Epidermis: #4 Stratum Corneum
- Most superficial layer.
- 20-30 layers of dead cells; flat membrane sacs filled with keratin.
- Some glycolipids in extra cellular space.
Layers of the Epidermis: #5 Stratum Lucidum
- ONLY IN THICK SKIN OF PALMS OF HANDS AND SOLES OF FEET
- Consists of 2-3 rows of dead keratinocytes
Define Apoptosis
- Occurs from stratum Basale all the way to stratum Corneum
- The cells break down, flatten, thicken, and shed away.
- No nucleus or organelles by the end of this process!
The 2 Layers of the Dermis:
- Papillary
- Reticular
2 Layers of the Dermis: #1 Papillary Layer
- Loosely woven aveolar tissue with collagen, elastic fibers, and blood vessels.
- Allows certain things to pass through while keeping harmful foreign products from entering.
Parts and Examples of the Papillary Layer:
Dermal Papillae: Many contain capillary loops while others house free nerve endings.
Epidermal Ridges: FINGERPRINTS! Also called Friction Ridges.
Two layers of the Dermis: #2 Reticular Layer
- 80% of the dermis.
- Coarse, irregular, dense fibrous tissue.
- Contains thick bundles of interlacing collagen fibers.
Example: Cleavage Lines- externally invisible lines that run longitudinally. Very important for surgeons when performing incisions.
The 3 Pigments that Contribute to Skin Color:
- Melanin
- Carotene
- Hemoglobin
The 3 Pigments that Contribute to Skin Color: #1 Melanin
- Only pigment made in skin.
- Color due to amount and form.
- Produce Melanocytes.
- Sun exposure stimulates secretes by keratinocytes that stimulate melanin production.
Examples: Freckles & Moles
What are Sun Spots:
Fungal infections not related to melanin.
The 3 Pigments that Contribute to Skin Color: #2 Carotene
- Yellow-Orange pigment in certain parts.
- Accumulates in Stratum Corneum and Hypodermis
- Can be converted to Vitamin A for vision and skin health.
The 3 Pigments that Contribute to Skin Color: #3 Hemoglobin
- Blood!
- Red blood cells all over the body that run through the blood stream and contribute to the color of skin
Skin Color Symptoms and Possible Diagnosis:
Cyanosis
- Blue!
- Low oxygenation of hemoglobin.
Skin Color Symptoms and Possible Diagnosis:
Erythema
- Red!
- Fever, hypertension, inflammation, or allergy.
Skin Color Symptoms and Possible Diagnosis:
Pallor
- Blanching; White
- Anemia, low blood pressure, fear, or anger.
Skin Color Symptoms and Possible Diagnosis:
Jaundice
- Yellowing
- Liver disorder
Skin Color Symptoms and Possible Diagnosis:
Bronzing
- Metallic
- Inadequate amounts of steroid hormones
Skin Color Symptoms and Possible Diagnosis:
Bruises
- Black and Blue
- Clotted blood beneath skin
Appendages of the skin:
- Hair and Hair follicles
- Nails
- Cutaneous glands: Sudoriferous (eccrine & apocrine) , Ceruminous, and Sebaceous (Oil)
Hair (Pili) functions and parts:
- Warms body, senses insects, guards from UV Radiation, heat loss, and physical trauma.
Parts:
- Hair Shaft
- Hair Root
The 3 Concentric layers of Hair:
- Medulla: Central core. Only part containing soft keratin.
- Cortex: Bulky layer surrounding medulla. Consists of several layers of flattened cells.
- Cuticle: Single Layer of Overlapping cells. Helps separate hairs so they don’t mat together. Most keratinized part making it very strong.
Structures of hair:
Hair Follicle
- Extend to Hypodermis.
- Deepest part located beneath skin’s surface.
Structures of hair:
Hair Bulb
- Small bulb at the end of the hair follicle
Structures of hair:
Hair Follicle Receptor (Root Hair Plexus)
- Knot of sensory nerve endings.
- Senses movement of hair.
Structures of hair:
Hair Papilla
- Contains knot of capillaries that supplies nutrients to growing hair.
Structures of hair:
Peripheral Connective Tissue Sheath and Epithelial Root Sheath
- What the wall of a hair follicle is composed of
Structures of hair:
Hair Matrix
- Actively dividing area of the hair bulb
Structures of hair:
Arrector Pili
- Bundle of smooth muscle cells.
- Evokes hair-raising response
Define Alopecia:
- Any level of baldness beginning in either sex
Definition of a Nail and It’s Parts:
- Scale-like modification of epidermis that is clear and protects the finger or toe.
- Nail Matrix: Responsible for nail growth.
- Nail Folds: Proximal and lateral borders that are overlapped by skin folds.
- Cuticle: End of nail
- Hyponychium: Thickened region beneath the free edge of a nail where dirt and debris accumulate.
Define Sweat (Sudoriferous) Glands and name the 4 types:
- Distributed over entire skin surface except nipples and other parts of the external genitalia.
- Eccrine (Merocrine)
- Apocrine
- Ceruminous
- Mammary
Sweat Sudoriferous Glands:
Eccrine (Merocrine)
- Abundant in palms, soles of feet, and forehead.
- Secretes sweat for temperature regulation
Sweat (Sudoriferous) Glands:
Apocrine
- Confined to Axillary, and anogenital areas.
- Lie deep in the dermis.
- Ducts empty into hair follicles.
- Secretes milky-yellowish fluid with generally unpleasant odor.
Sweat (Sudoriferous) Glands:
Ceruminous
- In external ear canal
- Secrete ear wax to block entrance of foreign materials to ear canal.
Sweat (Sudoriferous) Glands:
Mammary
- Secrete Milk
Sebaceous Oil Glands
- Simple branched alveolar glands
- Found everywhere except palms of hands and soles of feet.
- Secrete sebum
- Highly functional during puberty
Skin Cancer types, and Severity:
- Basal cell carcinoma: Least malignant. Most common. Mostly due to sun exposure.
- Squamous Cell Carcinoma: Second most common. Grows rapidly. Eliminated via surgery or radiation.
- Melanoma: Most dangerous. Resistant to chemotherapy. Most rare.
ABCD Skin Cancer Rule:
Asymmetry: Two sides of pigmented spot on mole don’t match
Border Irregularity: Border of lesion exhibits indentations.
Color: Pigmented spot contains several colors.
Diameter: Spot is larger than 6 mm in diameter.
Degree and Severity of Burns:
1st degree: only epidermis damaged. Localized redness, swelling, and pain.
2nd degree: Injure epidermis and part of dermis. Similar to 1st degree but blisters present.
3rd degree: Full-thickness burns. Area gray-white or cherry red. Nerve endings destroyed so little to no pain.
