Integumentary Lecture 2 Flashcards
What 3 pigments influence skin color
Melanin
Carotene
Hemoglobin
What is melanin produced by and in which layer is it produced?
Melanocytes in the stratum basale
What is melanin packaged into and where is it transferred?
Packeged into melanosomes and transferred to keratinocytes
2 types of melanin
- Eumelanin
- Pheomelanin
What are the pigments associated with eumelanin and pheomelanin
Eumelanin: brown, yellow-brown, black
Pheomelanin: pink, red, yellow
What is melanin made from
Tyrosine
What color is carotene? What is carotene
Orange-yellow pigment
Vit A precursor
Help protect skin
How does blood supply effect skin color
Blood flows through subpapillary plexus. More blood = redder color
What is erythema?
Skin redness due to capillary enlargement
What is cyanosis
Bluish color because of depleted oxygen in hemoglobin
what is pallor?
Paleness due to shock/anemia
Jaundice
Yellowing due to bilirubin
How is albinism caused?
- Inability to produce melanin due to mutation in gene.
- melanocytes cannot produce tyrosinase
How albinism affects someone
affects vision and sunburns easily
What is vitiligo
Disorder causing depigmentation
autoimmune - antibodies attack melanocytes
What are freckles?
Local increase in concentration of melanin
Genetic
What are age spots?
Accumulations of melanin due to sun exposure
What are moles? are they congenital or acquired
Benign overgrowth of melanocytes.
Can be both congenital or acquired
What are the ABCDEs of moles?
Assymetry
Borders
Color
Diameter
Evolving
How can malignant melanoma occur?
UV light exposure
Cancerous melanocytes grow and Metastasis through lymphatic system
What is the most common form of skin cancer?
Basal cell carcinoma
Where does basal cell carcinoma originate?
Stratum basale due to overexposure to UV
How does basal cell carcinoma appear
Transparent or pearly white nodule
Why do most people survive basal cell carcinoma?
virtually no metastasis
Where does squamous cell carcinoma originate
Squamous cells in surface layer of skin
What is hair composed of? Where is hair produced?
dead keratinized cells
Produced by hair follicles
3 functions of hair?
senses light touch
protection
prevent heat loss
What are the two regions of hair?
Hair shaft - near surface
Hair root - anchors hair into skin
3 layers of cells within hair shaft and hair roots?
- medulla
- cortex
- cuticle
Describe medulla
- maybe absent thin hair
- where pigment cells are
Describe cortex
- major part of hair shaft
Describe cuticle
- thin layer, flat keratinized cells
Where is soft keratin found?
Medulla or core of hair
Where is hard keratin found?
Cortex and cuticle
Where is the hair follicle found?
Dermis
Site of hair growth
7 main structures in hair follicle
- internal root sheath
- external root sheath
- glassy membrane
- connective tissue sheath
- hair bulb
- hair papilla
- hair matrix
Describe Internal root sheath
- surrounds hair root/deeper shaft
- prod by hair matrix
Where is external root sheath
skin surface to hair matrix