Flashcards in Integumentary System I and II Deck (79):
1
What are the essential functions of the integumentary system?
barrier
immunologic
homeostasis
sensory
endocrine
excretion
2
what type of epithelium makes up the epidermis?
keratinized stratified squamous epithelium
3
what is the epidermis derived from?
ectoderm
4
what type of tissue is the dermis made of?
dense CT
5
what is the dermis derived from?
mesoderm
6
what type of cells make up the stratum corneum?
keratinized cells
7
what is eleiden?
protein similar to keratin - transformation product of keratonhyalin
8
what type of skin is stratum lucidum found in?
thick skin only
9
what type of cells are found in the stratum basale?
mitotically active cells
10
what layers make up the stratum malpighii?
basale and spinosum
11
what type of cells make up the single layer of cells found in the stratum basale?
small, cuboidal to low columnar
12
how do the cells of the stratum basale attach to ECM while resting on basal lamina?
hemidesmosomes
13
what type of granules are found in the stratum granulosum?
keratohyalin granules
14
what is Parakeratosis?
keratin layer is abnormal - contains nuclear remnants
15
what is acanthusis?
abnormal epidermal thickening
- due to increase depth of stratum spinosum
common feature of many skin conditions
16
what layers make up the dermis?
papillary layer
reticular layer
17
what type of CT is found in papillary layer?
loose CT
18
what type of CT is found in reticular layer?
dense CT
19
what is the main cell type of epidermis?
keratinocytes
20
what are the cells of the epidermis?
keratinocytes
melanocytes
langerhan's cells
merkel cells
21
what type of cells Langerhan's cells?
antigen presenting cells
22
what types of cells are merkel cells?
cutaneous sensation
23
What are the two essentials activities of keratinocytes?
produce keratin
epidermal water barrier formation
24
what do keratohyalin granules contain?
intermediate filament associated proteins = filaggrin
trichohyalin
25
what are tonofilaments?
intermediate filaments = keratin filaments
26
what are tonofibrils?
bundles of tonofilaments
27
what is the ABCD rule of Malignant melanoma?
Asymmetrical
Border is irregular
Color variation
Diameter
28
where are the melanocytes in light skin?
concentrated near basal layer
29
where are the melanocytes in dark skin?
throughout the epidermis
30
in what skin is melanocyte degradation more rapid?
light skin
31
what does exposure to UV light accelerate?
melanin production
32
what is albinism?
lack of pigmentation
absence of tyrosinase - inability to produce melanin
33
what makes up merkel's corpuscle?
neuron and merkel's cells
34
what are the types of sensory receptors?
free and encapsulated
35
what are in free sensory receptors?
free nerve endings
merkels corpuscle
36
what makes up encapsulated sensory receptors?
pacinian corspuscles
krause's end bulb
meissner corpuscles
ruffinis corpuscles
37
what are the deep pressure receptors?
pacinian corpuscles
38
what are meissner's corpuscles?
touch receptors
39
what are nails?
plates of keratinized cells containing hard keratin
40
what does an eccrine sweat gland produce?
sweat
41
what does apocrine sweat glands produce?
mixed product -
sweat with high concentration of carbs lipids and proteins
42
what is the eponychium?
cuticle - hard keratin covering of nail root
43
what is hyponychium?
thick epidermal layer
secures free edge of nail plate at fingertip
44
what are the layers of the epidermis?
stratum corneum
stratum lucidum
stratum granulosum
stratum spinosum
stratum basale
45
where are stem cells present?
stratum basale of epidermis
46
how do the spinous processes of the cells in the stratum spinosum attach to adjacent cells?
desmosomes
47
what skin layer of the epidermis has a water barrier?
stratum corneum
48
which layer of the skin forms the regular tension lines of the skin called langer's lines?
reticular layer
49
what is in the reticular layer?
collagen type I and elastic fibers
50
what structural elements make up the epidermal water barrier of the keratinocytes?
cell envelope - insoluble proteins on inner plasma membrane
lipid envelope - lamellar bodies
51
what is the purpose of the epidermal water barrier?
maintian body homeostasis
essential for mammalian dry skin
52
what are lamellar bodies?
in lipid envelope
- glycosphingolipids, phospholipids, ceramides
- secreted by exocytosis
53
where are melanocytes found in epidermis?
stratum basale
54
where are melanocytes derived from?
neural crest cells
55
what does melanocytes do?
make and donate melanin to keratinocytes - keratinocytes phagocytize the tips of melanocyte processes (dendrites)
56
is the number of melanocytes equal in light skin and dark skin?
yes
57
what layer of epidermis is Langerhan's cells found?
stratum spinosum
58
where are merkels cells found?
stratum basale
59
what does the cytoplasm of merkels cells contain and what is it closely associated with?
dense neurosecretory granules
closely associated with terminal bulb of afferent nerve fibers
60
what is the function of Merkel's corpuscle?
mechanoreceptor
cutaneous sensation
61
where are pacinian corpuscles located?
deep dermis and hypodermis
- myelinated n. ending at one pole
- unmyelinated portion of axons extends to opposite pole
62
where are Meissner's corpuscles located?
dermal papillae of hairless skin - lips, fingers, toes
63
what types of nerves are found in Meissner's corpuscles?
unmyelinated endings of myelinated nerve fibers
64
what are epidermal skin appendages derived from?
downgrowths of epidermal epithelium during development
65
what are the epidermal skin appendages?
nails
hair follicles
sebaceous glands
eccrine sweat glands
apocrine sweat glands
66
what is hair?
keratinized cells containing hard keratin
67
what is nail bed continuous with?
stratum basale and spinosum of epidermis
68
which part of the nail is the germative zone?
nail matrix
69
what does hair color depend on?
content and type of melanin
70
what is the dermal sheath?
CT surrounding hair follicle
71
what is root sheath?
outer - 1 = cont. with epidermis
inner 2-4 = extends to sebaceous gland level
- henle's layer
- huxleys layer
- cuticle of inner sheath
72
how do sebaceous glands develop?
outgrowth of external root sheath of hair follicle
73
what is sebum?
oily substance
coats hair and skin surface
holocrine secretion
role in acne
74
what cells in sebaceous glands are mitotically active and sit on basal lamina?
basal cells
75
what is the function of eccrine glands?
regulate body temp
76
what are the two segments of eccrine sweat glands?
secretory - clear cells, dark cells, myoepithelial cells
duct
77
where are apocrine sweat glands found?
axilla
areola
gentitoanal
78
which sweat gland secretions contain pheromones?
apocrine sweat glands
79