Integumentary Lecture 2 Flashcards
1
Q
What 3 pigments influence skin color
A
Melanin
Carotene
Hemoglobin
2
Q
What is melanin produced by and in which layer is it produced?
A
Melanocytes in the stratum basale
3
Q
What is melanin packaged into and where is it transferred?
A
Packeged into melanosomes and transferred to keratinocytes
4
Q
2 types of melanin
A
- Eumelanin
- Pheomelanin
5
Q
What are the pigments associated with eumelanin and pheomelanin
A
Eumelanin: brown, yellow-brown, black
Pheomelanin: pink, red, yellow
6
Q
What is melanin made from
A
Tyrosine
7
Q
What color is carotene? What is carotene
A
Orange-yellow pigment
Vit A precursor
Help protect skin
8
Q
How does blood supply effect skin color
A
Blood flows through subpapillary plexus. More blood = redder color
9
Q
What is erythema?
A
Skin redness due to capillary enlargement
10
Q
What is cyanosis
A
Bluish color because of depleted oxygen in hemoglobin
11
Q
what is pallor?
A
Paleness due to shock/anemia
12
Q
Jaundice
A
Yellowing due to bilirubin
13
Q
How is albinism caused?
A
- Inability to produce melanin due to mutation in gene.
- melanocytes cannot produce tyrosinase
14
Q
How albinism affects someone
A
affects vision and sunburns easily
15
Q
What is vitiligo
A
Disorder causing depigmentation
autoimmune - antibodies attack melanocytes
16
Q
What are freckles?
A
Local increase in concentration of melanin
Genetic
17
Q
What are age spots?
A
Accumulations of melanin due to sun exposure
18
Q
What are moles? are they congenital or acquired
A
Benign overgrowth of melanocytes.
Can be both congenital or acquired
19
Q
What are the ABCDEs of moles?
A
Assymetry
Borders
Color
Diameter
Evolving
20
Q
How can malignant melanoma occur?
A
UV light exposure
Cancerous melanocytes grow and Metastasis through lymphatic system
21
Q
What is the most common form of skin cancer?
A
Basal cell carcinoma
22
Q
Where does basal cell carcinoma originate?
A
Stratum basale due to overexposure to UV
23
Q
How does basal cell carcinoma appear
A
Transparent or pearly white nodule
24
Q
Why do most people survive basal cell carcinoma?
A
virtually no metastasis
25
Where does squamous cell carcinoma originate
Squamous cells in surface layer of skin
26
What is hair composed of? Where is hair produced?
dead keratinized cells
Produced by hair follicles
27
3 functions of hair?
senses light touch
protection
prevent heat loss
28
What are the two regions of hair?
Hair shaft - near surface
Hair root - anchors hair into skin
29
3 layers of cells within hair shaft and hair roots?
1. medulla
2. cortex
3. cuticle
30
Describe medulla
* maybe absent thin hair
* where pigment cells are
31
Describe cortex
* major part of hair shaft
32
Describe cuticle
* thin layer, flat keratinized cells
33
Where is soft keratin found?
Medulla or core of hair
34
Where is hard keratin found?
Cortex and cuticle
35
Where is the hair follicle found?
Dermis
Site of hair growth
36
7 main structures in hair follicle
1. internal root sheath
2. external root sheath
3. glassy membrane
4. connective tissue sheath
5. hair bulb
6. hair papilla
7. hair matrix
37
Describe Internal root sheath
* surrounds hair root/deeper shaft
* prod by hair matrix
38
Where is external root sheath
skin surface to hair matrix
39
What does connective tissue sheath cover
epithelial cells of the hair follicle
40
what is the hair bulb
expanded base of hair follicle
41
what is hair papilla
CT filled with blood vessels and nerves
42
What is hair matrix
actively dividing basal cells in contact w/ papilla
43
what is hair root plexus
sensory nerves surrounding base of follicle
44
Arrector pili
muscle attached to hair follicle. for contraction
45
Sebaceous gland
prod. secretions to coat hair/skin surface
46
4 stages of hair growth
1. anagen (active)
2. catagen (regression)
3. telogen (resting)
4. exogen
47
What occurs during Anagen (active) hair growth
Hair matrix actively dividing to produce length ~0.33mm per day
48
What occurs during Catagen (regression) phase?
* Matrix stops dividing
* hair follicle atrophies
49
What occurs during telogen (resting) phase)
* Hair loses attachment
* becomes club hair
50
What occurs during exogen phase?
Club hair falls out of follicle
51
What is rate of hair growth dependent on?
* Genetics
* Nutrition
* Gender (hormones)
52
What are the two main types of hairs?
Describe each type
* **Terminal**
* Large, course, darkly pigmented
* **Vellus**
* smaller, shorter delicate
53
Ratios of hair types b/w male and female
* male: 95% terminal, 5% vellus
* female: 35% terminal, 65% vellus
54
What produces hair color? Name the type that prod. following hair colors:
dark hair
blond/red hair
grey hair
melanin produced by Melanocytes
* dark: eumelanin
* blond/red: pheomelanin
* gray: decreased melanin w/ decline of tyrosinase
55
What is alopecia and what causes it?
* partial or complete loss of hair
* caused by genes, endocrine disorder, chemo, skin disease
56
Androgenic alopecia
*
* Male pattern hair loss caused gentically predetermined by excessive response to androgens
57
Hirsutism
Excessive female/prepuberty males body hair
58
What do sebacious glands do? Where are they located?
* Holocrine exocrine glands that discharge oil (sebum) onto skin
* In dermis
59
What causes sebacious glands to release sebum?
Contractions of arrector pili muscle
60
What are sudoriferous (sweat glands) composed of? What are the two types?
Composed: myoepithelial cells
Types:
Eccrine sweat glands
Apocrine sweat glands
61
Where do eccrine glands secrete? Where are the highest number found?
Directly onto skin
Highest number found on palms
Important in thermoregulation
62
Where are apocrine glands located?
Where do they secrete?
Location: axillae, groin, nipples, pubic region
Open into hair follicle
Play role in body odor
63
Where are ceruminous glands located?
What do they produce?
Location: External auditory meatus
Produce cerumen (ear wax)
64
What causes pimples
Increased sebum blocks sebacous duct and hair follicle
65
What causes acne
Excessive sebum production or bacterial inflammation of sebacous glands
66
What is impacted cerumen
Abnormal abount of cerumen can prevent sound from reaching ear drum
67
What are nails composed of?
tightly packs keratinized epidermal cells
68
8 components that make up nails?
1. Nail body
2. nail bed
3. lunula
4. free edge
5. nail root
6. eponychium
7. hyponychium
8. nail matrix
69
What is nail body
bulk of visual part of nail
70
What is nail bed
skin beneath nail
71
WHat is lunula
White crescent shaped part proxmial end of nail body
72
What is free edge?
May extend past distal end of digit
white cause no capillaries under
73
What is nail root?
Portion of nail buried below skin
74
What is eponychium
Portion of stratum corneum extending over nail (aka cuticle)
75
What is hyponychium?
Thickened stratum corneum under free edge
76
What is nail matrix?
*
* Proximal portion of epithelium deep to nail root
Divide to produce new nail cells
77
# Age-related Changes to the Integument
what occurs due to fewer melanocytes
* Skin becomes pale
* more prone to sunburn
78
# Age-related Changes to the Integument
Why does a drier epidermis occur?
decreased sebacious gland activity
79
# Age-related Changes to the Integument
Why does a thinner epidermis occur?
Declining basal cell prod
Reduced D3 prod
80
# Age-related Changes to the Integument
What occurs due to diminished immune response
Less dentritic cells
Increased chance of skin damage
81
# Age-related Changes to the Integument
Why thinning dermis?
Fewer elastic fibers
Sagging and wrinkling
82
# Age-related Changes to the Integument
Why decreased perspiration?
Sweat glands less active
Increased chance for overheating
83
# Age-related Changes to the Integument
Reduced blood supply results in?
Cools skin, makes person feel cool even in warm room
84
# Age-related Changes to the Integument
Slower skin repair?
Takes longer to repair than in young adults
85
# Age-related Changes to the Integument
Fewer active follicle results in?
Thinner, finer hairs
86
How does sunlight cause production of vitamin D3
1. UV radiation cause cells in stratum basale and stratum spinosum to convert steroid into cholecalciferol
2. Liver creates intermediate product
3. Kidneys convert into calcitriol
87
Sources of vitamin D3 in diet?
fish, fish oils, shellfish, egg yolks, fortified foods
88
What can inadequate supply of calcitriol lead to? What pathology can it lead to in children
1. Impaired bone growth and maintenance
2. In children leads to rickets
89
How does epidermal wound healing occur?
1. Basal cells migrate across wound
2. Migration stops with contact with other cells
3. EGF stimulates basal cells to divide
90
What are the four phases of deep wound healing?
1. Inflammatory phase
2. Migratory phase
3. Proliferative phase
4. Maturation phase
91
What happens during the inflammatory phase of deep wound healing?
Blood clot unites wound edge
92
What happens during migratory phase of deep wound healing?
1. clot becomes scab
2. Epithelial cells migrate beneath scab to bridge wound **(Granulation tissue)**
3. fibroblasts form scar tissue
4. damaged blood vessels begin to regrow
93
What happens during proliferative phase of deep wound healing?
1. growth of epithelial cells beneath scab
2. fibroblasts lay down collagen randomly
3. blood vessel growth
94
What happens during maturation phase of deep wound healing?
1. Scab falls off when epidermis restored
2. collagen fibres become more organized
3. fibroblasts begin to disappear
4. blood vessels restored
95
What is the name for scar tissue formation
Fibrosis
96
Describe the following terms relating to scar tissue:
1. hypertrophic scar
2. keloid scar
1. hypertrophic scar - stays within original wound boundaries
2. keloid scar - extends beyond wound boundaries into normal tissue
