Chapter 5 Flashcards
- What system is the first line of defense against a hostile surrounding environment?
Integumentary System
- What are the two components of the cutaneous membrane?
a. Epidermis and dermis
- Describe the hypodermis.
a. A layer of loose connective tissue - SQ layer
- List and describe the 9 functions of the integumentary system.
a. Protection
b. Excretion
c. Maintenance
d. Production of melanin
e. Production of keratin
f. Synthesis of vitamin D3
g. Storage of lipids
h. Detection
i. Coordination of the immune response
- What kind of tissue makes up the epidermis? Describe this tissue.
a. Stratified squamous epithelium
b. Several layers of cells that are thin, flat, and irregular in shape.
- With the help of Spotlight Figure 5-3, label the five layers of the epidermis on thick skin on the following diagram. Which layer is absent in thin skin?
a. Stratum corneum
b. Stratum lucidum - Layer is in thick skin but not thin.
c. Stratum granulosum
d. Stratum spinosum
e. Stratum basale
Describe the structure and function of the stratum basale. Use the terms epidermal ridges, dermal papillae, basal cells, Merkel cells, tactile disc, and melanocytes in your description.
a. It is the deepest layer of the epidermis.
b. The stratum basale and the underlying dermis interlock, increasing the strength of the bond
c. Epidermal ridges extend into the dermis and are adjacent to dermal papillae, which are dermal projections that extend into the epidermis.
a. The ridges and papillae are important for the strength of the attachment between epidermis and dermis.
d. Basal cells are stem cells that divide to replace the more superficial keratinocytes.
e. Tactile cells are scattered among the stratum basale. The tactile cells and a nerve ending is the tactile disk.
a. Tactile cells are sensitive to touch
- Describe the structure and function of the stratum spinosum. Use the terms desmosomes and dendritic cells in your description.
a. Stem cells divides and is pushed superficial from the stratum basale. The stratum consists of 8 to 10 layers of keratinocytes that are bounded together by desmosomes.
b. Contains cells that participate in the immune response - dendritic cells
a. Defense against microorganisms and superficial skin cancers.
Describe the structure and function of the stratum granulosum. Use the terms keratin and keratinhyaline in your description.
a. 3 to 5 layers of keratinocytes. Most have stopped dividing and have started making large amounts of keratin. The cells grow thinner and flatter, their plasma membrane thicken and become less permeable.
b. The keratinocytes make a protein called keratohyalin which forms dense cytoplasmic granules that promote dehydration as well as aggregation and cross-linking of keratin fibers.
- Where is stratum lucidum found, and what sets it apart from the other layers of the epidermis?
a. Found in thick skin that covers the stratum granulosum.
b. Cells are flattened, densely packed, largely without organelles, and filled with keratin.
- Describe the structure and function of the stratum corneum. Use the terms keratinization and dead in your description.
a. 15 - 30 layers of keratinized cells.
b. Keratinization - “cornification” - formation of protective, superficial layers of cells filled with keratin.
c. The dead cells in each layer of the stratum corneum remain tightly interconnected by desmosomes.
- What is the difference between sensible and insensible perspiration?
a. Insensible - unable to see of feel the water loss
b. Sensible - Very aware of water loss
- Why are severe burns dangerous?
a. The damage breaks connections between superficial and deeper layers of the epidermis. Damage to the stratum corneum makes it a less effective as a water barrier, the rate of insensible perspiration increases.
What produces the orange-yellow pigment in skin? Where do we get this substance from?
a. Carotene - orange vegetables
- What produces the red-yellow or brown-black pigment in the skin? What cells produce this pigment?
a. Melanin - melanocytes
What accounts for the differences in skin pigmentation among individuals?
a. Where the transfer occurs of the pigmentation colors the keratinocyes.
a. Pale skin - transfer takes place in the stratum spinosum - cells more superficial lose their pigmentation
b. Dark-skinned the melanosomes are larger and more numerous, the transfer may occur in the stratum granuloseum.
- Besides giving skin its color, describe the protective function of melanin.
Protects against UV radiation by increasing the production of melanin.
What happens to the color of your skin when it gets warm, as if in a hot shower? Why does the skin change color?
a. Becomes red
b. The superficial blood vessels dilate so the skin can lose heat.
- Explain the following conditions:
Cyanosis, Jaundice, Vitiligo
a. Cyanosis - A decreased oxygen level in the hemoglobin - which turns a darker red but seen on the skin as bluish color.
b. Jaundice - The liver is unable to excrete bile, a yellowish pigment accumulates in body fluids
c. Vitiligo - individuals lose their melanocytes, causing white patches on otherwise normal skin