ANAT NOTES 5 Flashcards
(33 cards)
Skin - our largest organ
Accounts for 7% of body weight and varies in thickness from 1.5 to 4.4mm
What are the skins 3 distinct layers?
- Epidermis - 5 thin layers
- Dermis - TRUE SKIN
- Hypodermis - lies deep to the dermis
Is the hypodermis part of the integumentary system?
It is composed of areolar and adipose tissues; Not part of the integumentary system but shares some of skin’s properties
What are the 5 important functions of the skin?
- Protection
- Body temperature regulation
- Excretion
- Production of vitamin D
- Sensory reception
4 main cell types in epidermis
- Keratinocytes
- Melanocytes
- Tactile epithelial
- Dendritic cells
Keratinocytes
Stratum spinosum; produce keratin, a fibrous protein
Melanocytes
Basal layer; manufacture and secrete pigment (skin color)
Tactile epithelial
Basal layer; attached to sensory nerve ending
Dendritic cells
Stratum spinosum; part of immune system; macrophage-like
5 layers of the Epidermis (all begin with STRATUM; in descending order)
Corneum Lucidum (only in thick skin) manus and pedal Granulosum Spinosum Basale (stratum germinativum)
two layers of the dermis
- papillary dermis
- reticular dermis
dermal papillae
Increase surface area for exchange of gas, nutrients, and waste
Epidermal ridges
elevations of dermal ridges
Fingerprints
Reticular Dermis
Dense irregular connective tissue that accounts for 80% of dermal thickness
Cleavage lines
separation between collagen fibers
Aid in dissection; stretch marks
another name for hypodermis
superficial fascia
hypodermis contains what tissue?
areolar and adipose connective tissue
what is the different hypodermis distribution in males and females?
apple and pear configuration
What are the three pigments that contribute to skin color?
- melanin
- carotene
- hemoglobin
what are nails made of?
keratin and scalelike modification of epidermis
Hair
Flexible strand of dead, keratinized cells
2 chief parts of a hair
Root - root embedded in the skin
Shaft - project’s above skin’s surface
where do sebaceous glands NOT occur?
palms and soles
Holocrine secretion
entire cells breaks up to form secretion
