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Integumentary
Question | Answer |
---|---|
What are the general layers of the skin? | Epidermis - Dermis - Hypodermis |
Where can you find the thickest skin? | On the palms of hands and soles of the feet |
Where can you find the thinnest skin? | The thinnest skin is on the eyelids. |
Where can you generally find thick skin? | Any where that undergoes stress from abrasive forces |
Where can you generally find thin skin? | In places that are not subject to abrasion |
What is the value range for skin thickness? | 0.5-4mm |
How is skin an indicator of clinical conditions and dysfunction? | The skin will change colour depending on the conditions |
What is blue (cyanotic) skin an indicator of? | Hypoxemia |
What is yellow skin (jaundice) an indicator of? | Liver dysfunction |
What is red skin (erythema) an indicator of? | Heat, infection, inflammation, or allergic reaction |
What is white skin (palor) an indicator of? | Shock or anemia |
What are the six functions of the skin? | Temperature regulation, blood reservoir, protection, cutaneous sensations, metabolism, and excretion/absorption(minimal). |
What is the skins role in temperature regulation? | Maintenance |
How does the skin bring body temperature back to normal when it gets too hot? | Blood vessels in the skin dilate to transfer more heat to the surface. |
How does the skin bring body temperature back to normal when it gets too cold? | Blood vessels in the skin constrict to stop heat loss through the skin and extremities. |
What role do sweat glands play in temperature regulation? | Sweat aids in cooling the skin down through evaporation. |
How does the skin act as a blood reservoir? | The dermis carries 8-10% of the body's total blood volume. |
What is a benefit of the blood reservoir? | The blood can be redirected through constriction of blood vessels in times of need. |
What are 3 ways that the skin protects us? | Chemically, biologically, and physically |
How does the skin protect us chemically? | The skin secretes an oil that forms an acidic protective film that waterproofs and prevents growth of microbes |
How does the skin protect us physically? | It's continuity, thickness, and the keratin it contains. |
What is the purpose of continuity in the skin? | Prevents foreign bodies from entering |
What is the purpose of thickness in the skin? | Allows the skin to withstand abrasion |
What is the role of keratin regarding physical protection? | Glues the cells of the skin together to prevent breaking and tearing. |
How does the skin protect us biologically? | Immune cells hang around the stratum spinosum and activate the immune system when they detect a foreign body. |
What types of immune cells can be found in the skin? | Langerhan's and macrophages |
What are cutaneous sensations? | External senses that the skin conveys to the spinal cord such as pain, temperature, touch, pressure, etc. |
How does the skin aid in metabolism? | Provides the vitamin D precursor with UV light that creates an intermediary which must be activated by the kidney's and the liver to be functional. |
What is the skins minor contribution to excretion? | Excretes small amounts of ammonia and urea through sweat. |
What are the components of the integumentary system? | Skin, hair, nails, and glands. |
What is integumentary latin for? | Covering |
What are the layers of the epidermis (superficial to deep)? | Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale |
How many layers are found in the stratum corneum? | 25-30 |
What type of cells make up the stratum corneum? | Dead keratinocytes that contain only keratin. |
How do the cells of the stratum corneum fit together? | Within a layer they overlap like scales, between layers they interconnect like puzzle peices |
What is the function of the stratum corneum? | To protect the deeper layers from injury and microbial infection. |
How many layers are found in the stratum lucidum? | 4-6 |
What type of cells make up the stratum lucidum? | Flat, dead, clear keratinocytes |
What is the function of the stratum lucidum? | Reduces friction between the stratum corneum and the stratum granulosum |
Where can the stratum lucidum be found? | Only in THICK skin |
How many layers are found in the stratum granulosum? | 3-5 |
What types of cells are found in this layer? | Keratinocytes undergoing apoptosis |
What is apoptosis? | The orderly, genetically programmed death of a cell |
What is occurring within the cells of the stratum granulosum? | The nucleus and organelles are degenerating making the keratin intermediate filaments more prominent. |
What two things contribute to the name granulosum? | Keratohyalin and lamellar granules |
What is keratohyalin? | A protein that turns the intermediate filaments into keratin. |
What are lamellar granules? | Granules that release a lipid rich secretion when fused to the plasma membrane of a cell. |
What is the function of the lipid rich secretion produced by lamellar granules? | Provides a water repellent sealant that prevents the entry of foreign materials and the entry and loss of water. |
How many layers are in the stratum spinosum? | 8-10 |
Where does the stratum spinosum get its name from? | The spiny processes that appear when they shrink. |
What type of cell junction can be found within this layer? | Desmosomes |
Where can desmosomes be found within the stratum spinosum? | At the spiny processes that appear when the cell shrinks |
What types of cells can be found in this layer? | Living keratinocytes, langerhan's cells, and projections of melanocytes |
What organelles can be found in living keratinocytes? | Many ribosomes, a small golgi complex, some rough endoplasmic reticulum, and a few mitochondria |
How many layers are in the stratum basale? | 1 |
What is another name for the stratum basale? | Germinativum |
What is the function of the stratum basale? | This is the layer that creates new keratinocytes |
How does the stratum basale replace the keratinocytes that have been shed by the stratum corneum? | The stratum basale contains stem cells |
What types of specialized cells can be found in the stratum basale? | Merkel cells and their associated discs and melanocytes |
What types of cell junctions can be found in the stratum basale? | Hemidesmosomes and desmosomes |
What are epidermal/dermal ridges? | Down growths of epidermis into the dermis |
What is the function of rete ridges? | They increase the surface area between the epidermis and dermis allowing for an increase in the exchange of oxygen, nutrients and waste products, also aids in keeping the two layers together. |
What is a common name for rete ridges? | Fingerprints! |
What is the function of melanocytes? | Produce melanin |
What is the function of melanin? | Protects the skin from UV radiation and gives pigment to the skin and hair |
How does tanning work? | As you spend more time in the sun your melanocytes produce more melanin to protect your skin from harmful UV rays which causes you to "tan" |
What differs among people regarding melanocytes? | Everyone has the same number of melanocytes the difference is in how much melanin is produced. |
What is the role of Merkel cells and their associated discs? | Responsible for relaying touch sensations to the brain |
What is the role of keratin? | Keeps the cells together and aids in toughening and waterproofing the skin |
What are the three pigments that make up skin colour? | Melanin, carotene, hemoglobin |
What are some melanocyte alterations? | Albinism, Vitiligo, freckles/moles, melanoma |
What is albinism? | No melanin is produced |
What is vitiligo? | Loss of pigment in patches |
What are freckles/moles? | Concentrated melanocytes |
What is melanoma? | Cancerous mole |
What are the two regions of the dermis? | Papillary region and reticular region |
What is the dermis composed of? | Connective tissue containing collagen and elastin fibers |
What is the function of the dermis? | Provides the epidermis with nutrients |
What structures can be found in the dermis? | Blood vessels, nerves, glands, and hair follicles. |
What types of cells are present in the dermis? | Fibroblasts, macrophages and a few adipocytes |
What is the papillary region composed of? | Thin collagen and elastin fibers |
How is the surface area of the papillary region increased? | Dermal ridges |
What can be found in dermal papillae? | Capillaries, Meissner corpuscles, and free nerve endings |
What are Meissner corpuscles? | Nerve endings sensitive to touch |
What is the reticular region composed of? | Thick collagen fibers, scattered fibroblasts, and various wandering cells (such as macrophages). |
What two characteristics does the dermis have? What contributes to this? | Extensibility and elasticity. The combination of elastin and collagen fibres |
What is the most predominant cell in the dermis? | Fibroblasts |
What are fibroblasts? | Type of cell that synthesizes the ECM and collagen. |
What is the hypodermis composed of? | Areolar and adipose tissue |
What is the function of the hypodermis? | Storage for fat and contains large blood vessels that supply the skin, insulates and cushions body |
Is the hypodermis a part of the skin? | No |
What are the types of skin glands? | Sebaceous, Eccrine, and Apocrine |
Where can you find sebaceous glands? | Connected to the hair follicles of the body. |
What do sebaceous glands secrete? | Sebum |
What is the function of sebum? | Prevents evaporation of water from skin, keeps skin soft, inhibits growth of some bacteria, and prevents hair from becoming dry and brittle. |
Where are eccrine glands? | Throughout the body but most common on forehead, palms, and soles. |
What category of gland do eccrine glands belong to? | Sudoriferous Glands |
What do eccrine glands secrete? | Sweat |
Where are you most likely to find apocrine glands? | In the armpits, groin, areolae of the breasts, bearded regions of males faces. |