Term
| The integumentary system accounts for ____ % of total body weight. |
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Definition
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Term
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Definition
| The network of arteries and veins servicing the integument. |
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Term
| What is the hypodermis, and is it part of the skin? |
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Definition
| It is the subcutaneous layer of fat beneath the skin. It is the superficial layer of the fascia. |
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Term
| What are epidermal ridges and dermal papillae. |
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Definition
| This epidermal and dermal projections increase surface area so that the two layers can be bound together more strongly. |
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Term
| What layer is "thicker" or "thinner"? |
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Definition
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Term
| From top to bottom, what are the layers of the epidermis? |
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Definition
Cranes Lift Great Solid Beams
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale. |
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Term
| Describe the Stratum corneum: |
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Definition
- Most superficial layer of skin.
- 15-30 layers of dead, keratinized cells.
- The cells, though dead, are still connected by desmosomes.
- Cells move into the s. corneum after 7-10 days, and remain there for around 2 weeks before falling off. |
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Term
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Definition
- Found only the thick skin of the palms and soles of the feet, this separates the s. corneum from s. granulosum.
- Cells contain both keratin and keratohyalin. |
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Term
| Describe the s. granulosum: |
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Definition
- Thin, dark, "Grainy Layer", separates s. spinosum from s lucidum.
- 3-5 layers of keratinocytes. |
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Term
| Describe the s. spinosum: |
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Definition
- 8-10 layers bound by desmosomes.
- spinosum means "spiny" - somebody thought the cells look like small pincushions.
- This layer also contains dendritic cells that identify antigen markers on pathogens. |
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Term
| Describe the stratum basale: |
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Definition
- basal layer of epidermis.
- germ cells which divide in order to create new layers of skin cells.
- contain touch sensitive Merkel cells. |
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Term
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Definition
| Pigmentation cells that live in the s. basale. They produce melanin. |
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Term
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Definition
| Vesicles filled with melanin that are passed to other cells. |
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Term
| What is melanin made from? |
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Definition
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Term
| What happens to the melanosomes? |
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Definition
| They are transferred intact to the keratinocytes. There, they color the cell until the melanosome contents are destroyed by lysosomes. |
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Term
| How does the skin of darker-complected individuals differ from their lighter-complected counterparts? |
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Definition
| People with darker complexion have the same amount of melanocytes, but they release larger melanosomes, and can transfer them to the cells in more superficial layers. |
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Term
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Definition
| an orange-yellow pigment found in the s. corneum. |
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Term
| What are the three molecules that effect skin color in people? |
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Definition
| Melanin, carotene, and hemoglobin. |
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Term
| What is the most common class of cancers, and the most common cancer in that class? |
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Definition
| Skin cancers; basal cell carcinoma. |
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Term
| How does melanin protect cells from UV light. |
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Definition
| It blocks UV light from hitting the nucleus and causing chromosomal damage. |
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Term
| What is the most dangerous skin cancer? |
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Definition
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Term
| What are the two layers of the dermis, from superficial to deep? |
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Definition
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Term
| What is the primary tissue making up the papillary layer? |
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Definition
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Term
| What other structures are found in the papillary layer? |
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Definition
| Capillaries, lymph vessels, sensory neurons. |
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Term
| What is the primary tissue found in the reticular layer? |
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Definition
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Term
| What other structures are found in the reticular layer? |
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Definition
| blood vessels, lymph vessels, nerve fibers, hair follicles, sweat glands. |
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Term
| How does the reticular layer hold the skin together? |
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Definition
| Collagen fibers, heavy within the reticular layer, also extend superficially into the papillary layer, and deep into the hypodermic layer. |
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Term
| What is the purpose of sub-q tissue? |
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Definition
- stabilize skin relative to underlying structures.
- Storage of energy. |
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Term
| What are Merkel cells, and what do they interface with? |
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Definition
| Light-touch receptors; tactile discs, which are afferent nerve endings. |
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Term
| Where are Merkel cells located? |
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Definition
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Term
| What other sensory receptors are located in the epidermis? |
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Definition
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Term
| What are tactile (Meissner's) corpuscles? |
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Definition
| Light touch receptors found in the dermis. |
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Term
| What are lamellated (Pacinian) corpuscles? |
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Definition
| Deep pressure/vibration receptors found in the dermis. |
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Term
| What are lines of cleavage, and how are they clinically significant? |
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Definition
| They show orientation of collagen and elastic fibers. Surgical cuts made parallel will heal easily, while perpendicular cuts will leave a larger scar. |
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Term
| What are the accessory structures of the skin? |
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Definition
| Hair follicles, exocrine glands, and nails. |
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Definition
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