Module 1: Skin Flashcards
(117 cards)
1
Q
How much percent of body is skin?
A
16%
2
Q
Skin covers how much surface area?
A
1.5-2m^2
3
Q
Functions of skin include
A
protection, excretion, thermoregulation, producing melanin and keratin, storing lipids, synthesising vitamin D and detecting aspects of touch
4
Q
Layers of the skin from outermost to innermost
A
epidermis, dermis and hypodermis
5
Q
Four layers of epidermis from outermost to innermost
A
stratum corneum, stratum granulosum, stratum spinosum and stratum basale
6
Q
is the epidermis shed
A
Yes
7
Q
is there circulation to the epidermis
A
no
8
Q
the epidermis can be described as a
A
keratinocyte conveyor
9
Q
the protein fibres in the dermis are
A
collagen and elastin
10
Q
is the dermis shed
A
no
11
Q
does the dermis nourish the epidermis
A
yes
12
Q
the function of the hypodermis is
A
insulation
13
Q
the hypodermis is made from
A
adipose tissue
14
Q
thick skin contains an extra layer of
A
epidermis
15
Q
thick skin is found in places
A
like the palms of hands and soles of feet, places with no hair
16
Q
a thin dermis leads to
A
sagging and wrinkling
17
Q
sagging and wrinkling is due to a lack of
A
collagen
18
Q
as the skin ages there is a
A
slower skin repair
19
Q
drier epidermis is due to
A
less sebum
20
Q
less pigmentation results in
A
pale skin and grey hair
21
Q
accessory structures of skin include
A
hair, acne, sweat glands, receptors and nails
22
Q
the structure of hair is
A
hair shaft, hair follicle, arrector pili muscle and sebaceous gland
23
Q
increased acne risk is caused by
A
increased sebum
24
Q
function of nails
A
protect fingertips and enhance sensation
25
melanin absorbs
UV light
26
What is the function of melanin absorbing UV light
protects cells against UV damage
27
where is melanin produced
melanocytes
28
melanocytes are transferred to epidermal cells by
melanosomes
29
a mole is
a cluster of melanocytes
30
sun exposure can cause
over proliferation
31
freckles are caused by
melanocytes overproducing melanosomes
32
overproduction of melanosomes is caused by
sun exposure
33
melanocytes are only found in the
stratum basale
34
melanosomes are found in
epidermis
35
density of melanocytes varies throughout the ___ but not between ___
body; races
36
Vitamin D is essential for
normal calcium metabolism and strong bones
37
Vitamin D deficiency affects
bone strength and moods
38
what type of pigmented people are more susceptible to vitamin D deficiency
highly pigmented in extreme latitudes
39
What country has one of the highest rates of skin cancer in the world
NZ
40
Basal cell cacinoma originates in the
stratum basale
41
metastasis is rare in which skin disease
basal cell cacinoma
42
malignant melanoma originates in the
melanocytes
43
metastasis is highly common in which skin disease
malignant melanomma
44
Tattoo
artificial pigmentation deposited deep within the skin
45
tattoos are in which layer of the skin
dermal
46
immune cells can do what to pigment
capture it but not break it down
47
types of tattoo include
trauma, decorative and cosmetic
48
receptors of the skin are
free nerve endings, tactile discs, tactile corpuscles, lamella corpuscles and bulbous corpuscles
49
the most common receptor in the skin is
free nerve endings
50
structure of free nerve endings
mostly unmyleinated small diameter fibres but also some small diameter myelinated fibres which usually have small swellings at distal ends
51
the small swellings on the distal ends of free nerve endings are called
sensory terminals
52
function of sensory terminals
cation channels--> depolarization--> APs
53
free nerve endings respond to
temperature, painful stimuli, some movement/ pressure/ itch.
54
tactile discs are
free nerve endings located in deepest layer of epidermis
55
tactile discs are associated with
large disc shaped epidermal (merkel) cells
56
the communication between merkel cells and nerve ending is due to
serotonin (5HT)
57
tactile discs are abundant where
fingertips and very small receptive fields
58
tactile discs respond to
objects physical features ie. texture, shape and edges. fine touch and light pressure
59
tactile corpuscles are located
in papillary layer of dermis
60
tactile corpuscles are found mainly in
thick skin
61
are tactile corpuscles encapsulated
yes
62
tactile corpuscles sense
fine and discriminative touch, light pressure and low frequency vibration.
63
lamellar corpuscles are scattered
deep in with dermis and hypodermis
64
structure of lamellar corpuscles
single dendrite lying with concentric layers of collagen fibres and specialised fibroblasts
65
collagen layers of lamella corpuscles are separated by
gelatinous interstitial fluid
66
lamellar corpuscles are sensitive to
deep pressure
67
bulbous corpuscles are also known as
ruffinis endings
68
bulbous corpuscles are located in
dermis and subcutaneous tissue
69
structure of bulbous corpuscles
network of nerve endings intertwined with a core of collagen fibres that are continuous with those of the surrounding dermis. capsule surrounds the entire structure,
70
bulbous corpuscles are sensitive to
sustained deep pressure, stretching and distortion of skin
71
bulbous corpuscles can be commonly found in
joint capsules
72
a high density of bulbous corpuscles can be found
around fingertips
73
why is there is a high density of bulbous corpuscles around fingertips
to allow for modulation of grip
74
the sympathetic nervous system does what to smooth muscle to regulate temperature in skin
smooth muscle in walls of arteries and pre-capillary sphincters innervated by SNS
75
noradrenaline acts on ___ on this vascular smooth muscle in the skin
alpha 1 adrenergic receptor
76
noradrenaline acting on alpha 1 adrenergic allows
GPCRs coupled to the intercellular 2nd messengers
77
GPCRs coupled to the intercellular 2nd messengers allows for
an increased intracellular Ca++ and therefore constriction of skin blood vessels.
78
eccrine sweat glands are innervate
by the sympathetic nervous system
79
sympathetic chollinergic
release ACh into mAChRs (GPCRs)
80
some eccrine sweat glands can also be stimulate by ___ when nervous
adrenaline in blood acting on beta receptors
81
when body temp increases a ___ on skin blood vessels results in ___
decrease SNS activation of alpha 1; vasodilation
82
when body temp increase an ___ on sweat glands results in ___
increase SNS cholinergic activation of mAChRs; sweating
83
what area of the hypothalamus contains heat and cold sensitive neurons
preoptic area
84
heat and cold sensitive neurons are also known as
central thermoreceptors
85
heat generating mechanisms include
shivering, non-shivering thermogenesis, increase in thyoxine
86
method of shivering
increased tone skeletal muscle, when tone rises above critical level, shivering begins due to oscillatory contractions of agonist and antagonist muscles mediated by muscle spindles (stretch receptors)
87
method of non-shivering thermogeneis
increase sympathetic nerve activity and increase circulating adrenaline/noradrenaline from adrenal medulla
88
an example of increased cellular metabolism is
increased glycogenolysis in liver and muscle
89
heat production instead of ATP occurs in what fat
brown
90
heat production instead of ATP is the result of
uncoupling of oxidative phosphorylation
91
an increase in thyroxine is the result of
a response to TRH and TSH
92
an increase in thyroxine increases
basal metabolic rate
93
arrector pili muscles are
smooth muscle innervated by SNS alpha 1 receptors
94
arrector pili muscles attach
hair follicle to upper dermis
95
function of arrector pili muscle
contraction pulls hair upright and dimples skin ie. goosebumps and also compressesd sebaceous glands which lubricate skin
96
first degree burns are
superficial and only involve the outer layers of epidermis
97
first degree burns look
red, pink, dry and painful
98
are there blisters in first degree burns
no
99
how long do first degree burns take to heal
3-10 days
100
second degree burns involve what layers of skin
epidermis and varying amounts of dermis
101
second degree burns look
painful, moist, red and blistered
102
how long do second degree burns take to heal
1-2 weeks
103
third degree burns involve what tissue
full thickness ie. into the subcutaneous tissue and may involve muscle and bone.
104
third degree burns look
varied in colour from waxy white through to deep red or black. hard dry and leathery
105
are third degree burns painful
no, as these areas do not contain any working sensory nerve endings
106
how long do third degree burns take to heal
weeks to regenerate plus scarring
107
rule of 9s
helps us work out % of total body surface area involved.
108
in an adult TBSA of head is
9%
109
in an adult TBSA of upper limb is
9%
110
in an adult TBSA of trunk is
36%
111
in an adult TBSA of lower limb is
18%
112
in an adult TBSA of genitalia is
1%
113
in an child TBSA of head is
15%
114
in an child TBSA of trunk is
32%
115
in an child TBSA of upper limb is
9%
116
in an child TBSA of lower limb is
17%
117
in an child TBSA of genitalia is
1%
