Integumentary system Flashcards
Dermatology
Study of skin
The largest organ of the body
Skin
Organization of skin (superficial to deep)
- Epidermis
- Dermis
- Subcutaneous Layer (Hypodermis)
The epidermis is composed of
- Stratified squamous epithelium tissue
- 4-5 layers
2 main cell types in epidermis
- Melanocyte
- Keratinocytes
Keratinocytes
- 90%
- Contains Keratin
- A tough protein that protects skin and waterproofs it
Melanocytes
- 10%
- Produces Melanin
- Pigment
- Transforms melanin to keratinocytes
Layers of the epidermis (superficial to deep)
- Stratum Corneum
- Stratum Lucidum
- Stratum Granulosum
- Stratum Spinosum
- Stratum Basale
Stratum Basale
- Bottom layer of the epidermis
- Layer the cells that are actively dividing (mitosis)
Stratum Spinosum
- 8-10 cell layer
- Begin to look flattened
Stratum Granulosum
- Forms water-repellant sealant for the skin
- Keratinocytes start to die
- Include lamellar granules
Apoptosis
Death of cells
Lamellar Granules
Waterproofing lipids
Stratum Lucidum
- Only found in areas with thick skin
- Fingertips, palms, soles of feet - Extra layer of dead cells
Stratum Corneum
- Top layer of the epidermis
- Largest layer (25-30 layers of dead keratinocytes)
Psoriasis
- Disorder in epidermis
- Abnormal dividing of the skin
- keratinocytes divide too quickly in stratum corneum
- Skin forms flaky, silvery scales
Callus
- Disorder in epidermis
- Abnormal thickening of the epidermis
- Overworking the skin speeds up division for extra protection.
Dermis
-Connective tissue
2 major regions of the dermis
- Papillary Region
- Reticular Region
Papillary Region
- Superficial layer of dermis
- Fingerprints
- Contain Touch Receptors
Dermal Papillae
fingertip projections in the dermis which cause grooves in the epidermis
Meissner’s Corpuscles
Touch Receptors
Reticular Region
- Deep layer of the dermis
- Contains hair follicles, nerves, oil glands, and sweat glands
- stretch marks form
Stretch marks
Streaks on the skin caused by small tears in the dermis due to extreme stretching of the skin
Subcutaneous Layer
- AKA hypodermis
- Areolar and adipose connective tissue
- Blood Vessels
- Pressure Receptors
Pacinian Corpuscles
Pressure Receptors
Hair
- Found of most body surfaces
- For protection
3 structures of hair
- Shaft
- Root
- Follicle
Shaft
Portion of hair that projects from the skin
Root
Portion of hair embedded in the dermis
Follicle
Skin sheath which surrounds the root
Arrector Pili Muscle
- Raises hair
- Causes goosebumps
- Smooth Muscle
Sebaceous (Oil) Glands
- Produce sebum to coat hair and skin
- Keeps from drying out
- Almost always connected to the hair follicle
Acne
Inflammation of Sebaceous glands
Sudoriferous (Sweat) Glands
- Produces sweat that leaves skin through pores
- Includes sweat, water, salt, waste
- 2 types of sudoriferous glands
- Eccrine
- Apocrine
Eccrine (sweat) glands
Regulate body temp. through sweat
Apocrine (sweat) glands
Releases sweat into hair follicles
-found in armpits and groin areas
Ceruminous Glands
Produces ear wax (Cerumen)
-For protection
Structure of Nails
Hard epidermal cells to protect ends of digits
Melanin
A brown-black skin pigment
More melanin= darker color
Carotene
Yellow-orange pigment in adipose tissue
Hemoglobin
Contributes a reddish color to skin depending on blood flow
Vasodilation
- Increased blood flow to the skin surface
- As blood flows near the surface, heat is given off
Vasoconstriction
Decreased blood flow to skin surface to conserve heat
Leading cause of cancer is
Excessive sun exposure
Basal Cell Carcinoma
- Most Common
- Occurs in Stratum Basale
- Rarely metastasizes
Squamous Cell Carcinoma
- Occurs in upper epidermis
- May metastasizes
Malignant Melanoma
- Occurs in Melanocytes
- Deadly because it metastasizes rapidly
- 50% survival rate
1st Degree Burn
- Mild
- Only involves epidermis
2nd Degree Burn
- Damages epidermis and part of the dermis
- Blisters
3rd Degree Burn
- Destroys all layers
- Long recovery
- Skin grafts may be needed
Athlete’s Foot
-Fungal Infection of the foot
Chicken Pox
- Highly contagious viral infection
- Shingles
Shingles
Caused by chicken pox virus
-Lesions form on nerve pathways
Cold Sore
- A sore
- Usually in/around the mouth
- Caused by herpes virus
Alopecia
Baldness
Bedsores
-Constant deficiency of blood flow to a tissue caused by prolonged pressure
Eczema/ Dermatitis
- Itchy, red skin inflammation
- Rash
5 Functions of Skin
- Protection: a barrier to infection, chemicals, dehydrations/evaporation, and sun
- Synthesis of Vitamin D
- Excretion: Sweat
- Sensation: Touch, Pressure, temperature, pain
- Regulation of body temperature (Thermoregulation)
