| a. Protect against bacteria, chemicals, UV, and physical abrasion
b. Regulates body temp
c. Sensation reception
d. Synthesis of vitamin D from cholesterol
e. Blood reservoir: 8-20% of total volume found in dermis | 5 functions of skin |
| Epidermis, dermis | Describe the two principle layers of skin |
| Stratum Basale: cell division
Stratum Spinosum
Stratum Granulosum: thin layer of keratinocytes
Stratum Lucidum: fingertips, palms, soles (dead keratinocytes)
Stratum Corneum: contains corneocytes (different keratinocytes) | List Layers of epidermis |
| Papillary Layer
Reticular Layer | What are the two layers of the dermis? |
| Areolar CT (elastic and collagen fibers) | What CT is in papillary layer? |
| Dense irregular CT (significantly thicker: 80% of thickness in dermis) | What CT is in Reticular Layer? |
| Forms extensions that reach out into the epidermis and contain capillaries that facilitate transport of nutrients | What does the dermal papillae found in papillary layer do? |
| Found in the dermal papillae | Where is the meissner's corpuscles located |
| Cleavage lines run longitudinally; less dense areas of CT form these lines | What are cleavage (tension) lines? |
| Small glands that secrete oily matter (sebum) to skin and hair folicles
Found in Reticular layer | what are sebaceous glands and where are the found? |
| Fibroblasts, myofibroblasts, macrophages, and lymphocytes (immune cells) | What cells do both layers contain? |
| Located in reticular layer
dead kerantinized cells | Where are hair follicles found and what cells hold them together? |
| Reticular Layer | Where are sweat glands found? |
| Start in reticular layer and goes our through epidermis
Gives us goosebumps and is found right by hair root | Where are arrector pili muscles found and what is their function? |
| Adipocytes (fat cells: 1/2 of fat reserve stored here)
Areolar CT | What cells and CT are found in the subcutaneous layer? |
| Below reticular layer (not considered a part of skin) | Where is the subcutaneous layer found? |
| Passageway for blood vessels and nerves from dermis to muscles and helps protect bones and muscles from damage | What is the function of the subcutaneous layer? |
| all over entire surface of skin except nipples and parts of genitalia | Where are glands found on body? |
| ductless glands that secrete hormones into interstitial fluid and then picked up by blood vessels (IN BODY) | Endocrine gland |
| Have ducts and secrete fluid OUTSIDE of body | Exocrine (same as eccrine) |
| watery secretion by exocytosis, cool down through exaporative cooling, get rid of waste (water/electrolytes)
Saliva, sweat from palms, soles of feet, everywhere else | Merocrine (eccrine) function and example (Exocrine) |
| Release secretion from top of cell (top of cell breaks off to release proteins, lipids, steroids), release contents into hair folicle
Apocrine sweat glands, mammary glands, ceruminous glands
Emotional sweating (most active during times of stress/anxiety) | Apocrine function and example (exocrine) |
| Entire cell breaks down to release sebum, lubricates skin, slows bacterial growth
Found in face, chest, back
sebaceous glands | Holocrine function and example (exocrine) |
| Merocrine: temperature regulation | Show how functional classification of exocrine glands is related to the mode by the cells to deliver their secretory products (merocrine) |
| Scent glands | Show how functional classification of exocrine glands is related to the mode by the cells to deliver their secretory products (apocrine) |
| Secrete ear wax | Show how functional classification of exocrine glands is related to the mode by the cells to deliver their secretory products (ceruminous) |
| secrete milk | Show how functional classification of exocrine glands is related to the mode by the cells to deliver their secretory products (mammary) |
| Epidermal appendages that develop from the epidermis but are located within the dermis
Hair follicle: formed within epidermal root, but nourished by dermal papillae
Arrector Pili Muscles: attaches to hair follicles
Nails
Goosebumps | Definition of epidermal derivative and the organs found in this category |
| Melanin: brown pigment produced by melanocytes
Carotene: yellow-orange pigment found in stratum corneum and subcutaneous layer
Hemoglobin: from red blood cells | Components that contribute to skin color |
| cancer of the epithelium (most common) | Carcinoma |
| Cancer of connective tissue | Sarcoma |
| Arises from abnormal growth of stratum basale in which cells lack ability to produce keratin
Does not spread
78% of all cancers | Basal Cell Carcinoma |
| Arises from stratum spinosum
May spread
20% of all skin cancers | Squamous Cell Carcinoma |
| Most dangerous
Spreads rapidly and can kill a person within months of diagnosis
Arises from melanocytes of preexisting moles
3% of all skin cancers | Malignant Melanoma |
| -Damage to epidermis
-Blood vessels in dermis causing edema and redness
-Heal in 2-3 days
-No scarring, no blisters, tender | 1st degree burn |
| -Damage to both epidermis and dermis
-Blisters: tissue fluid accumulates between epidermis and dermis
-Pain: usually quite painful
-Epidermis regenerates from edge of burn
-Epithelium from hair follicle and sweat glands usually takes 2-3 weeks to heal and might scar
-2nd degree burns are critical if <30% of surface is burned | 2nd degree burn |
| -damage to epidermis, dermis, hair follicles, sweat glands, pain receptors, subcutaneous layer
-Painless but life threatening because of fluid loss and bacterial infection
-Critical if <10% of surface area is burned | 3rd degree burn |
| -Mobilizes body's defenses
-Isolates and destroys microorganisms
-Removes damages cells so repair can proceed | Vascular and cellular response in preparation for tissue repair (1st step) |
| Histamine: from mast cells
Prostaglandins (from damaged cells) | Chemical mediators of inflammation releases by damaged tissues include |
| -Vasodilation of blood vessels (heat and redness)
-Stimulate pain receptors
-Increase permeability of vessels
-Blood clot forms during inflammation (formed from protein and fibrin which come from blood) | What are the actions of histamine and prostaglandins? |
| -Neutrophils arrive as part of inflammation response
-Injured tissue and bacteria release chemicals that attract white blood cells
-Ingest bacteria and cellular debris
-Neutrophils killed in process and accumulates as a mix of dead cells and fluid (pus)
-Macrophages remove dead neutrophils and cellular debris | Phagocytosis: to clear area for repair |
| -Clot becomes a scab
-Extensive growth of epithelial cells beneath scab occurs
-Epithelium cells from sides of wound migrate beneath scab, eventually meeting and covering wound
-Fibroblasts surrounding migrate to the clot along the fibrin threads and synthesize scar tissue
-Damaged blood vessels begin to regrow
-Granulation tissue: tissue filling the wound | Organization Phase |
| -Extensive growth of epithelial cells beneath scab
-Scab sloughs off once epidermis is restored to normal thickness
-Collagen deposition in random patterns and become more organized
-Continued growth of blood vessels until restored to normal | Regeneration Phase |
