Questions and Answers
What tissue types compose the epidermis and dermis?
The epidermis is composed of stratified squamous epithelium, and the dermis is composed of dense irregular connective tissue proper.
List the major layers of the epidermis.
Stratum Basale, Stratum Spinosum, Stratum Granulosum, Stratum Lucidum, Stratum Corneum.
What is the function of the stratum corneum?
The stratum corneum protects the skin against abrasion and penetration and waterproofs the skin.
What are the two layers of the dermis?
Signup and view all the answers
What factors contribute to skin color?
Signup and view all the answers
What is the main function of sweat glands?
Signup and view all the answers
What separates eccrine from apocrine sweat glands?
Signup and view all the answers
What are the three layers of keratinized cells in hair?
Signup and view all the answers
What type of cancer is the least malignant?
Signup and view all the answers
Why are serious burns life threatening?
Signup and view all the answers
What is the 'Rule of Nines' used for?
Signup and view all the answers
What defines a 2nd degree burn?
Signup and view all the answers
What characterizes a 3rd degree burn?
Signup and view all the answers
Study Notes
Tissue Types in Skin
- Epidermis: Composed of stratified squamous epithelium; 4-5 layers; thicker in palms, fingertips, and soles.
- Dermis: Composed of dense irregular connective tissue; consists of two layers.
Layers of the Epidermis
- Stratum Basale: Deepest layer; single row of stem cells; rapid division; 10%-25% melanocytes.
- Stratum Spinosum: Several layers thick; irregular keratinocytes with desmosomes; spiny appearance due to tissue preparation.
- Stratum Granulosum: 3-5 layers thick; keratinization occurs; cells filled with keratin; lamellar granules provide water resistance.
- Stratum Lucidum: Only in thick skin; 1-2 rows of clear, dead keratinocytes.
- Stratum Corneum: Outermost layer; 20-30 cell layers thick; provides protection and waterproofing; made up of dead keratin-filled cells.
Dermis Layers
- Papillary Layer: Loose areolar connective tissue; 20% of dermis; contains blood vessels and dermal papillae.
- Reticular Layer: Deeper layer; dense irregular tissue; accounts for 80% of dermal thickness.
Skin Color Factors
- Determined by melanin, carotene, and hemoglobin.
- Sun exposure can darken and damage skin, increasing risk of skin cancer.
Pigments Affecting Skin Color
- Melanin: Polymer of tyrosine; provides natural protection against UV.
- Carotene: Yellow-orange pigment; found in thick skin areas; can convert to vitamin A.
- Hemoglobin: Contributes to pinkish hue; visible through the transparent epidermis, more pronounced in Caucasian skin.
Sweat Glands
- Eccrine: Abundant on palms and forehead; coiled tubular glands; produce sweat for thermoregulation.
- Apocrine: Found in axillary and anogenital areas; secrete milky sweat with fatty substances; function begins at puberty; odor can develop with bacterial interaction.
Oil Glands (Sebaceous)
- Simple branched alveolar glands; secrete sebum; found everywhere except palms and soles; linked to hair follicles.
Hair Follicle Components
- Hair Bulb: Deep end of follicle where hair growth begins.
- Hair Follicle Receptor: Sensory nerve endings wrapped around each hair bulb.
- Hair Papilla: Contains capillaries supplying nutrients for hair growth.
- Wall of Hair Follicle: Composed of connective and epithelial sheaths.
- Hair Matrix: Site of active cell division leading to hair production.
Hair Structure
- Shaft: Visible part of hair; keratinization complete.
- Root: Portion embedded in the follicle; keratinization ongoing.
Hair Composition
- Medulla: Central core with soft keratin.
- Cortex: Bulky layer surrounding the medulla.
- Cuticle: Overlapping outer layer; provides strength.
Skin Functions
- Protection: Three barriers—chemical, physical, biological.
- Body Temperature Regulation: Insensible perspiration; sweat glands help cool the body.
- Cutaneous Sensation: Rich supply of sensory receptors; respond to external stimuli.
- Metabolic Functions: Vitamin D synthesis; chemical conversions.
- Blood Reservoir: Can hold 5% of total body blood volume; redistributes blood as needed.
- Excretion: Removes waste products through sweat.
Skin Cancer Types
- Basal Cell Carcinoma: Most common and least malignant; shiny nodules; nearly 99% cure rate.
- Squamous Cell Carcinoma: Arises from keratinocytes; lesions appear as scaly red patches; good cure prospects if caught early.
- Melanoma: Most dangerous; highly metastatic; arises from melanocytes; early detection crucial.
Burns
- Life Threatening: Serious burns cause dehydration and infection; can lead to renal failure and shock.
- Extent Assessment: Rule of nines divides body into 11 areas, each accounting for 9% of total body area.
-
Burn Degrees:
- 1st Degree: Affects only epidermis; redness and pain; heals in 2-3 days.
- 2nd Degree: Involves epidermis and part of dermis; blisters; heals in weeks with minimal scarring.
- 3rd Degree: Destroys entire skin depth; may require skin grafts; little to no pain due to nerve damage.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of the tissue types and layers of the epidermis and dermis. This quiz covers the major layers and their functions, enhancing your understanding of skin anatomy. Perfect for students preparing for exams or looking to reinforce their learning.