Integumentary System Flashcards
Integumentary system: 2 components that make up the cutaneous membrane
Epidermis (epithelium)
Dermis (connective tissue)
Integumentary system: 3 accessory structures
- exocrine glands
- hair
- nails
4 tissue types
- epithelium
- connective tissue
- muscle (smooth)
- nerve
What is the largest organ system of the body?
Skin (15%)
Where is the thinnest skin on the human body? How thick is it?
- eyelid
- 0.5 mm
Where is the thickest skin on the human body? How thick is it?
- heel of foot
- 4.0 mm
What is the average thickness of skin?
1-2mm
What is the area (m^2) that your skin covers?
2 m^2
What are the 3 layers of the skin?
- epidermis
- dermis
- hypodermis (fat storage)
What is the name of the specific interface between dermis and epidermis?
Peak-and-valley interface
- allows for a tight bond b/n diff layers of skin (can resist shearing stresses)
The structure of the epidermis has 5 layers. Name them from deep to superficial.
Stratum:
- germinativum
- spinosum
- granulosum
- lucidum
- corneum
Another term for stratum germinativum.
stratum basale (@ base of epidermis)
As the keratinocytes begin to move up from the deep to superficial layers of the epithelium, they start to flatten out. What shapes do they take over the process?
round > oval > flat
T/F:
Keratinocytes are still capable of division in the stratum spinosum.
True.
Keratinocytes are less capable of division the closer they are to the superficial layer of the epithelium.
How are keratinocytes Held together in the stratum spinosum?
Desmosomes - protein linkage b/n adjacent cell junctions
Which layer in the epidermis is responsible for the production of large quantities of keratohyalin and keratin?
Stratum granulosum
Which layer of the epidermis is only found in volar skin (palmar and plantar skin)?
stratum lucidum
Which layer of the epidermis the most adapted for protection against abrasion and microbial invasion?
stratum corneum.
also a water repellent barrier
Which structure of skin contains nerve endings?
dermis (layer)
The two layers the dermis consists of:
- papillary layer (thinner, areolar, with nerve endings)
- reticular layer (thicker, compact connect tissue, elastic fibres)
Structure of skin where subcutaneous fat is stored (amount/ distribution differs between sexes).
hypodermis (aka superficial fascia)
What is the function of a Merkel cell? Where is it found?
- touch sensation/ receptor
- stratum germinativum/ basale of epidermis
What type of specialized skin cell is phagocytic and plays an important role in immune function?
Langerhans cells (found in epidermis)
What type of specialized skin cell forms the basis of skin colour?
Melanocytes (forms 8% of epithelial cells)
What pigment within the skin gives a yellow/ orange colour?
carotene
What pigment within the skin gives a red/ yellow colour?
pheomelanin
What pigment within the skin gives a brown/black colour?
melanin
What do melanocytes transfer to keratinocytes to colour them (via pigmentation)?
melanosomes
Accessory structures:
2 types of exocrine glands
- sweat glands
- sebaceous glands (secrete oily lipid)
2 types of special apocrine glands
- ceruminous glands (ear wax)
- mammary glands (milk production)
3 types of hairs
- vellus hairs (fine)
- intermediate (limbs)
- terminal (coarse)
What is club hair?
Hair that does not grow anymore, in “rest” phase for about 3 months.
