Integument Flashcards
What constitutes the integumentary system?
- Skin2. Sweat glands3. Sebaceous glands4. Hair5. Nails
What type of epithelium makes up the epidermis?
Stratified squamous keratinized
What type of epithelium makes up the dermis?
- Loose CT2. Dense irregular collagenous CT
What layer of skin is injured in superficial burns?
Epidermis
What are the nonkeratinocytes?
- Langerhans cells2. Merkel cells3. Melanocytes
What is the primary function of Langerhans cells?
Defense
What is the precursor of Langerhans cells?
Bone marrow
Where are Langerhans cells mainly located?
Stratum spinosum
Which cell type is responsible for antigen presentation in the skin?
Langerhans cells
Birbeck granules are unique to what type of cell?
Langerhans cell
What is the main function of Merkel cells?
Mechanoreceptor
Where are Merkel cells mainly located?
Stratum basale (many in fingertips and base of hair follicles)
How are Merkel cells attaced to keratinocytes?
Desmosomes
The Merkel cell - neurite complex is responsible for what sensation?
Discriminative touch - picking up fine detailed sensory information such as shape and texture
What is the main function of melanocytes?
Protection from UV radiation
What is the precursor of melanocytes?
Neural crest
Bone marrow is the origin for what nonkeratinized cell of the epidermis?
Langerhans cells
Neural crest is the origin for what nonkeratinized cell of the epidermis?
Melanocytes
What pigment do melanocytes synthesize?
Melanin
Where are melanocytes mainly found?
Stratum basale and superficial dermis
What nonkeratinized cell type of the epidermis is found in the stratum basale and superficial dermis?
Melanocytes
What nonkeratinized cell type of the epidermis is found in the stratum spinosum?
Langerhans cells
What nonkeratinized cell type of the epidermis is found in the stratum basale?
Merkel cells
The cytoplasmic processes of melanocytes project into what layer of the epidermis?
Stratum spinosum
Where is tyrosinase synthesized?
rER
When is tyrosinase incorporated into melanosomes?
After Golgi processing
When and where is tyrosine converted to melanin?
In the melanosome, post-Golgi
What contributes to level of pigmentation in different races / people?
- Tyrosinase activity2. Number of melanin granules3. Size of melanin granules4. Distribution of melanin5. Rate of melanin breakdown
From superficial to basal, what are the strata of THICK skin?
- Stratum corneum2. Stratum lucidum3. Stratum granulosum4. Stratum spinosum5. Stratum basale (germinativum)
What is the general function of the stratum corneum?
Protection
What are characteristics of the stratum corneum?
- Flattened, dessicated, keratinized, dead cells2. No nuclei or organelles3. Keratin filaments and amorphous matrix4. No desmosomes - desquamate
What is the general function of the stratum lucidum?
Protection
What are characteristics of the stratum lucidum?
- Sublayer of stratum corneum2. Perceptible in thick skin3. No organelles of nuclei4. Keratin filaments
What is the general function of the stratum granulosum?
Waterproofing
What are characteristics of the stratum granulosum?
- Nucleated - apoptotic nuclear morphology2. Keratohyalin granules3. Membrane-coated granules
In which layer of epidermis are membrane-coated granules found?
Stratum granulosum
In which layer of epidermis are keratohyalin granules found?
Stratum granulosum
What is contained within the membrane-coated granules of the stratum granulosum?
Lipid
What is the general function of the stratum spinosum?
Binding, protection
What are characteristics of the stratum spinosum?
- Interdigitating processes (intercellular bridges)2. Bundles of intermediate filaments (tonofilaments - cytokeratin)3. Membrane-coating granules4. Mitosis in basal layer5. Langerhans cells
What is the general function of the stratum basale?
Cell renewal, anchor epidermis to basement membrane
What are characteristics of the stratum basale?
- Single layer of cells2. Desmosomes laterally, hemidesmosomes basally3. Most intense mitotic activity
What are the strata of THIN skin?
- Stratum corneum2. Stratum spinosum3. Stratum basale
What is the “glue” of the basement membrane holding the epidermis to the dermis?
Carbohydrates
What is the “anchor” of the basement membrane holding the epidermis to the dermis?
Collagen fibers
Which embryonic germ layer gives rise to the dermis?
Mesoderm
Structure and strength of the dermis is provided via what protein?
Collagen
What feature of the dermis - epidermis layer is responsible for fingerprints?
Dermal ridges
What are the layers of the dermis?
- Papillary 2. Reticular
The papillary layer of the dermis contains what types of connective tissue fibers?
- Type III collagen (reticular)2. Type VII collagen (fibrils to anchor dermis to epidermis)3. Some elastic fibers
Partial thickness burns involve what layer of skin?
Dermis
The reticular layer of the dermis contains what types of connective tissue fibers?
- Type I collagen - regular orientation2. Thick elastic fibers
In which layer of the dermis are hair follicles, arrector pili muscles, sebaceous glands, and sweat glands found?
Reticular layer
What is the general function of eccrine glands?
Thermoregulation
Where are eccrine glands located?
Deep in dermis or hypodermis
What type of epithelium makes up the secretory segment of eccrine glands?
Simple cuboidal to low columnar (or pseudostratified)
What type of epithelium makes up the duct segment of eccrine glands?
Stratified cuboidal epithelium
Where are apocrine glands located?
Deep dermis and hypodermis of axilla, areola, anus, external auditory meatus, eyelids
Which glands have myoepithelial cells associated with them?
Eccrine glands
What is the secretory method for apocrine glands?
Merocrine
Where are sebaceous glands located?
Dermis and hypodermis throughout body, numerous in scalp and face
In sebaceous glands, where are the immature cells located?
Periphery
What is the secretory method for sebaceous glands?
Holocrine
What type of epithelium makes up the duct segment of sebaceous glands?
Stratified squamous epithelium
Where does nail growth take place?
Nail matrix (root)
Where are Merkel cells located?
Stratum basale of epidermis (non partying regions of the skin)