The Integumentary System Flashcards
1
Q
what is the only body system consisting of only one organ
A
integumentary system - skin and embedded appendages
2
Q
how much does the skin weigh on average
A
11 pounds
3
Q
describe the functions of the integumentary system
A
- protection against microorganisms, abrasion, and UV light
- barrier to water loss
- richly and densely innervated for sensory reception
- start of vitamin D production
- thermoregulation
4
Q
describe how the integumentary system functions in protection
A
- mechanical protection against abrasion and normal friction
- absorbs UV light to protect underlying structures
- protections against the invasion of microorganisms
5
Q
describe how the integumentary system aids water retention
A
- tight connections of epithelial cells prevents extreme water loss
- water resistant, not waterproof
6
Q
is UV light from the sun high or low energy radiation
A
- high energy radiation
- lowest level of high energy radiation
7
Q
is vitamin D a hormone
A
yes, both hormone and vitamin
8
Q
what is the target cell of vitamin D and what does it do
A
- target cell is simple columnar epithelial tissue between the small intestine and blood vessels
- stimulates cells to uptake Ca+ from food to the bloodstream
9
Q
what are the 2 major layers of the skin
A
- epidermis
- dermis
10
Q
what is another name for the skin
A
cutaneous membrane
11
Q
what are the three tissue types in the skin
A
- stratified squamous epithelial tissue in the epidermis
- areolar connective tissue in the dermis
- dense irregular connective tissue in the dermis
12
Q
describe the structure of the epidermis
A
- thinner than the dermis
- thickness can vary greatly
- stratified squamous epithelial tissue
- avascular: no blood supply
- free nerve endings detect itching, pain, discomfort
13
Q
describe the structure of the dermis
A
- made of connective tissue: areolar and dense irregular
- rich blood supply
- densely innervated
14
Q
what portion of the dermis is areolar connective tissue
A
- 20%
- edge closer to the top/epidermis
15
Q
what portion of the dermis is dense irregular connective tissue
A
- 80%
- edge closer to the bottom/hypodermis
16
Q
describe the action, origin, and insertion of the arrector pili muscle
A
- action: contracts to move hair follicle vertically
- origin: in the skin between the epidermis and the dermis
- insertion: base of the hair follicle in the dermis
17
Q
why/when does the arrector pili muscle contract
A
- when experiencing heightened emotional state
- helps thermoregulation in some mammals
18
Q
what causes goose bumps
A
contraction of the arrector pili muscle
19
Q
are sebaceous glands exocrine or endocrine glands
A
- exocrine gland
- empties secretion into the hair follicle and epidermis
20
Q
what do sebaceous glands produce
A
sebum (oil)
21
Q
describe the functions of sebum from the sebaceous glands
A
- moisturizes hair and prevents breakage
- keeps the epidermis moist
- contains defensin proteins that protect against bacteria
22
Q
describe the mode of secretion that sebaceous glands use
A
- holocrine secretion
- superficial cells rupture, releasing the solution and becoming a part of it
- new cells replace ruptured cells
23
Q
describe the hair follicle
A
- encapsulates hair at the root
- anchors hair in place
- protects the hair, allowing it to grow
24
Q
what is another name for sweat glands
A
sudoriferous glands
25
what are the two types of sweat glands
- eccrine
- apocrine
26
what tissue composes the subcutaneous tissue
adipose connective tissue
27
what is the function of the subcutaneous layer
- protects underlying structures
- padding
- insulation
28
describe why women have more adipose tissue in their subcutaneous tissue layer
- estrogen stimulates adipose tissue growth
- extra adipose tissue can give energy for a growing baby because fat in the highest density and most efficient storage for energy
29
which is singular and which is plural: stratum, strata
- singular: strata
- plural: stratum
30
describe the overarching significance of the structure of the epidermis
- almost all of the structure of the epidermis is made from keratinized stratified squamous epithelial tissue
- structure is geared toward producing lots of cells at the bottom and moving them to the top layer within 40-60 days
- in that process, cells are modified to be tougher, stronger, dead, and water resistant to protect structures underneath
31
what are the layers of the epidermis from deepest to most superficial
- stratum basale
- stratum spinosum
- stratum granulosum
- stratum lucidum
- stratum corneum
32
how many total cells are in the human body
75-100 trillion cells
33
how far away can cells be from a capillary to stay alive
8-10 cells away
34
what is the stratum basale layer of the epidermis attached to
the basement membrane
35
how many cell layers are in the stratum basale
1-2 cell layers thick
36
what type of cells make up the majority of the stratum basale
- epidermal skin cells
- not keratinized, not keratinocytes
37
describe the fate of daughter cells from the stem cells in the stratum basale
- one daughter cell moves to the next layer (stratum spinosum) to become a keratinocyte
- one daughter cell stays in the stratum basale as a stem cell
38
what is the main function of the stratum basale
- making lots of cells
- making keratinocytes for the rest of the epidermis and replenishing stem cell reserves
39
are desmosomes or hemidesmosomes unique to the stratum basale
- desmosomes are not unique to the stratum basale; they connect all cells of the epidermis
- hemidesmosomes are unique to the stratum basale; they connect cells to the basement membrane
40
how many cell layers are in the stratum spinosum
8-10 cell layers thick
41
explain why the stratum spinosum has that name
- spiny layer
- cells are preserved in a hypotonic solution that causes the cells to shrink but desmosomes still anchor cells to one another; this causes a spiny/pointy appearance
- cells do not actually have spines, the appearance is an artifact of preparation
42
how does the concentration of desmosomes change as you move up the layers of the epidermis
higher desmosome concentration as you get more superficial
43
what is the main function of the stratum spinosum
- produce keratin as cells begin to keratinize
- form lamellar bodies
- cells become tougher and more water resistant
44
how do cells begin to keratinize in the stratum spinosum
intermediate filaments form protein filaments called keratin fibers
45
are cells still alive in the stratum spinosum
yes, only beginning to keratinize
46
describe lamellar bodies
- pockets of glycolipids
- helps make the epidermis water resistant
47
explain why cells start to die after the stratum spinosum
- cells must be less than 8-10 cells away from a capillary to survive
- the stratum spinosum can be up to 8-10 cells thick
- there are no capillaries in the epidermis
- cells at this point are now 8-10 cell layers away from the nearest capillary so they are not getting the nutrients needed to survive
48
define apoptosis
- cell suicide, cell death
- done for a good reason, such as cell death in the epidermis
49
define necrosis
cell death due to disease or injury
50
how many cell layers are in the stratum granulosum
2-5 cells thick
51
describe why the stratum granulosum has that name
- cells look grainy due to keratohyalin granules
52
are cells still alive in the stratum granulosum
yes
53
describe the function of cells in the stratum granulosum
- increasing keratin production, keratohyalin granules
- cells filling with soft keratin to become firm
- making a fibrous shell under the cell membrane to toughen up
54
describe keratohyalin granules
- in the stratum granulosum
- keratin proliferating from nexus points in cells as so much is being produced
55
why type of keratin is produced in the epidermis
soft keratin
56
describe the two things that make the epidermis water resistant
- keratinized cells stops water from moving through cells
- glycolipids from lamellar bodies in the interstitial space stop water from moving between cells
57
how many cell layers are in the stratum lucidem
5-10 cells thick
58
where on the body is stratum lucidem found
- areas that experience the most friction
- palms, fingers, soles of feet
59
describe why the stratum lucidem has that name
- lucid layer
- lucid means being clear
- the stratum lucidem is a transparent layer of cells
60
why does the stratum lucidem appear clear
there are no keratohyalin granules
61
describe why the stratum corneum has that name
- cornified layer
- becoming dry and hard
62
describe the structure of cells in the stratum corneum
- lay next to each other like shingles
- very tough
- flattened
- dead
- full of soft keratin
- still have desmosomes
63
are desmosomes still present in the stratum corneum
yes
64
how many cell layers are in the stratum corneum
25-50 cells thick
65
what is the main function of the stratum corneum
protect everything underneath
66
what is the lifespan of keratinocytes in the epidermis
45-60 days for keratinocytes that is born to reach the outer layer and slough off
67
what does thick skin refer to
- the thickness of the epidermis only
- having a stratum lucidem
68
where is the cutaneous membrane (epidermis and dermis) the thickest
- between the shoulder blades
- 5mm
69
where is the cutaneous membrane (epidermis and dermis_ the thinnest
- eyelids
- 0.5mm
70
what is the function of melanocytes
- manufacture melanin
- give melanin to keratinocytes to protect cells from UV light
71
what is melanin
skin pigment
72
where are melanocytes found
- stratum basale, tentacles radiate into stratum spinosum
- anchored to the basement membrane
73
what enzyme to melanocytes produce and what is it's function
- produce the enzyme tyrosinase
- tyrosinase polymerizes chains of tyrosine which is used to make melanin
74
describe the life cycle of melanin
- manufactured in melanocytes
- packaged into vesicles called melanosomes
- cytoskeleton of melanocyte moves melanosome through the cell tentacles
- keratinocytes phagocytize melanosomes
75
what does melanin do to/for keratinocytes
- darkens the cell
- shields DNA against UV light
76
what are the positives and negatives of UV light hitting the skin
- positive: needed to make vitamin D
- negative: can mutate DNA and cause cancer
77
what determines the amount of melanin an individual has
- genetics
- environment
78
which country has the most UV light
Australia
79
what are the advantages and disadvantages of having darker skin
- advantage: melanin protects DNA from mutation (skin cancer)
- disadvantage: less efficient at making vitamin D in low level light
80
where are merkel cells found
- stratum basale
- right next to basement membrane
81
why are merkel cells in the stratum basale, next to the basement membrane
the cell makes a connection with a nerve ending in the dermis
82
are merkel cells neurons
- no
- quasi-neuron
83
what types of touch set of merkel cells
- light touch receptors
- low frequency vibration
84
what is another name for dendritic cells
langerhans cells
85
why are langerhans cells sometimes called dendritic cells
they were firstly thought to be a type of neuron due to the branching structure
86
where are langerhans cells commonly found
- stratum spinosum
- epidermal tissue lining organs
87
what is the function of langerhans cells
- immune cell
- similar in function to macrophages by phagocytizing
88
where are langerhans cells made
bone marrow
89
describe how langerhans cells protect the body from pathogens
- cells can move between other cells in the stratum spinosum
- phagocytize pathogens and partially digest them
- bring partially digested pathogen to nearest lymph node
- lymphocytes will follow the path and finish off all pathogens left
90
describe the nerve supply in the dermis
richly and densely innervated
91
define nociceptors
pain nerve endings
92
are there nerves within the hair follicle
yes
93
describe the structure and function of nerves in the hair follicle
- network of nerves embedded within follicles (nerve plexus)
- extremely sensitive to being stretched or compressed
- can detect very light touches of the hair
94
why can you feel when you have goosebumps
nerve plexus within hair follicles
95
why is it important to have nerve endings within a hair follicle
- can detect light touch that merkel cells can't
- can detect when mosquitoes land on you
96
where are meissners corpuscles located
- papillary layer of the dermis
- right under the epidermis
97
what do meissners corpuscles feel
light touch
98
are meissners corpuscles cellular
no
99
describe the difference between adaptive and nonadaptive receptors
- adaptive: can feel sensation when first stimulated but will stop reacting after a while
- nonadaptive: won't ever stop reacting to a sensation no matter the duration
100
are meissners corpuscles adaptive or nonadpative
adaptive
101
what receptors are always nonadaptive
pain receptors
102
what sensations do ruffini end organs detect
continuous touch or pressure
103
are ruffini end organs adaptive or nonadaptive
nonadaptive
104
what sensations do pacinian corpuscles detect
- deep pressure
- high frequency vibration
105
are pacinian corpuscles cellular
no
106
describe the structure of pacinian corpuscles
- fibrous layers, like an onion
- nerve ending goes into the center
107
are nociceptors adaptive or nonadaptive
nonadaptive
108
describe how pacinian corpuscles receive sensations
- touch pushes on the corpuscle and deforms it
- compresses the nerve ending inside which detects the sensation
109
what are the three layers of the hair from internal to external
- medulla
- cortex
- cuticle
110
what does medulla always mean in anatomy
center core
111
what does cortex literally mean
bark
112
where is the wavy border between the epidermis and the dermis most pronounced
- palms
- fingertips
- soles of feet
113
what does the wavy border between the epidermis and the dermis create/do
- fingerprints
- helps to grip things
114
define lanugo
long, delicate, and unpigmented hair covering a fetus in the womb
115
define terminal hairs
- long, coarse, and pigmented hair
- stick out from the skin and can be seen easily
116
where are terminal hairs found before puberty
- scalp
- eyelids
- eyebrows
- nostrils
117
where are the longest growing terminal hairs found
scalp
118
define vellus hairs
short, fine, usually unpigmented hair
119
where does terminal hair replace vellus hair after puberty
- pubic and axillary regions
- chest, legs, and arms (more in men than women)
- facial hair in men
120
what is the function of hair in most mammals
- camouflage
- thermoregulation
121
describe why the areas and thickness of terminal hair growth is highly variable after puberty in men
- people having different testosterone levels
- people's target cells for testosterone expresses less/more receptors
122
describe the medulla of the hair
- central axis of the hair
- 2-3 layers of cells containing soft keratin
123
describe the cortex of the hair
- surrounds the medulla
- forms bulk of the hair
- cells containing hard keratin
124
describe the cuticle of the hair
- covers the cortex
- single layer of overlapping cells
- cells containing hard keratin
125
what are the two components of a hair follicle
- dermal root sheath
- epithelial root sheath (internal and external)
126
which epidermal strata in the external epithelial root sheath are at the opening of the hair follicle and which are at the hair bulb
- opening: all strata found in thin skin
- hair bulb: only stratum basale
127
what often comes out around the hair root when a hair is pulled out
internal epithelial root sheath
128
what does the matrix inside the hair bulb produce
- hair
- internal epithelial root sheath
129
describe the hair papilla
- portion of the dermis that projects into the hair bulb
- contains blood vessels that provide nourishment to the cells of the matrix
130
what two stages do hair have
- growth stage
- resting stage
131
what does the length of the growth/resting stage depend on
where the hair is/the type of hair
132
what is the growth and resting stage length of scalp hair
- growth stage: 3 years
- resting stage: 1-2 years
133
how many scalp hairs are in the growing stage at any given time
90%
134
what is a normal amount of scalp hairs to lose per day
100
135
what is the average rate of hair growth
0.3 mm per day
136
what muscle as associated with each hair follicle
arrector pili
137
where are vellus hairs found
widely distributed across the entire body
138
what is a slang name for vellus hair
peach fuzz
139
describe how the hair serves a protective purpose
- protects the scalp from UV light
- filters particles that enter the nose
- eyebrows and eyelashes serve as a protective barrier for the eyes
- arrector pili muscles allow you to feel any movement of the hair
140
define mechanoreceptors
receptors that detect vibration, touch, and pressure
141
define sudoriferous glands
- sweat glands
- eccrine and apocrine glands
142
where are eccrine glands found
the dermis
143
describe the structure of an eccrine gland
- coiled body in the dermis
- duct leading to the surface of the skin
144
where do you have a high density of eccrine glands
- head
- neck
- torso
145
what is the function of eccrine glands
thermoregulation through evaporative cooling
146
how do eccrine glands spring into action so quickly
- each sweat gland is individually innervated
- signals sent directly to the gland from the brain
147
which sudoriferous gland is important physiologically and which is less important
- important: eccrine glands
- less important: apocrine glands
148
what is sweat from eccrine glands composed of
- mostly water
- NaCl
- nitrogenous wastes
149
does the skin have an excretory function
- yes
- very small excretory function through sweat
150
what is the pH of sweat
6.6-6.8
151
what is the pH of blood
7.4
152
is sweat acidic or basic
acidic (pH 6.6-6.8)
153
how many more H+ ions are in sweat than in blood
- sweat pH 6.6-6.8
- blood pH 7.4
- sweat has about 10x more H+ ions than blood
154
define the acid mantle
the mixture of sweat and oil on the surface of the skin
155
what is the purpose of the acid mantle
bacterial retarding effect
156
describe why the acid mantle has a bacteria retarding effect
- the acid mantle contains oil and sweat
- oil contains defensins and sweat is acidic
- bacteria on the skin adapt to the acidic environment
- if bacteria enter the body, they will be less likely to survive in the blood which is more basic
157
describe why the acid mantle is useful if it doesn't eliminate all chances of bacterial infection
although some bacteria will adapt to the basic environment of the blood, it will cause a delay in infection and gives the immune system more time to respond
158
where are apocrine glands found compared to eccrine glands
- apocrine glands are found deeper than eccrine glands
- may be all the way in the hypodermis (subcutaneous layer)
159
which sweat glands are larger
apocrine glands
160
when are apocrine glands activated
- during puberty
- activated by testosterone and estrogen
161
when are apocrine glands often stimulated
- sexual activity
- nervousness
162
where are apocrine glands found on the body
- pubic region
- axillary regions
163
what are the components of apocrine glands
- same components as eccrine glands: water, NaCl, nitrogenous wastes
- also pheromones
164
what is the purpose of pheromones in apocrine gland sweat
- signaling sexual maturity to mates
- less needed nowadays
165
which sweat glands make you smell bad
apocrine glands
166
why do apocrine sweat glands make you smell bad
- apocrine gland sweat contains proteins and fats
- bacteria feed on these nutrients and create smelly waste
167
what is the term for how the blood vessels in the skin help with thermoregulation
radiative cooling
168
define radiative cooling
- one way the skin uses to thermoregulate (blood vessels dilating)
- radiating heat to a cooler environment
169
where is there a blood supply in the skin
dermis
170
describe what happens to blood vessels in the skin when you get hot
- blood vessels close to the surface dilate
- hot blood flow under the skin releases heat to the environment
171
how do blood vessels near the skin surface dilate/contract
- sphincter around the artery before the blood vessel enters the skin allows it to dilate or contract
- direct impulse sent to the sphincter from the brain
172
define sphincter
- smooth muscle
- allows tubular organ to relax/contract
173
describe what allows blood vessels to dilate within the dermis
dense irregular connective tissue moves to allow space for the blood vessels to dilate
174
what is a visual sign that blood vessels near the skin surface are dilating
erythema: skin turning pink or red
175
is it easier to visually see blood vessel dilation under the skin in someone with more or less melanin
easier to see dilation in someone with less melanin
176
describe what happens to blood vessels in the skin when you get cold
- blood vessels close to the surface constrict
- blood in conserving heat near internal organs
177
what is a visual sign that blood vessels near the skin surface ae constricting
the skin will turn pale or blue
178
describe why the skin may turn blue if you are cold
- blood vessels constrict
- deoxygenated blood will stay in the blood vessels near the skin surface
179
define cyanosis
skin being a bluish color
180
when might someone be cyanotic
- if they are too cold
- heart attack
- obstruction stopping breathing
181
define erythema
- red color on the skin
- any kind of reddening on the skin
182
when might someone have erythema
- high blood pressure
- too hot
- infection
183
define juandice
yellowing of the skin
184
where does jaundice appear on the body
- globally distributed (whole body)
- easily seen in the whites of the eyes, gums, and nails
185
where would you look for jaundice on someone with a darker complexion
- whites of eyes
- gums
- nails
186
why does jaundice occur
- production of excess bilirubin
- liver issues such as hepatitis
187
what percentage of infants have jaundice when they are born
33%
188
describe why it is so common for infants to have jaundice when they are born
- the lungs don't work as a fetus, oxygen is taken in through the placenta
- fetal hemoglobin helps intake oxygen as it has a much stronger binding force than regular hemoglobin
- when a baby is born, they switch the regular hemoglobin
- the liver is involved in adapting to regular hemoglobin
- the liver may be overworked and malfunction during the adaptation leading to jaundice
189
what is the treatment for jaundice
being in the light
190
is bilirubin hydrophobic or hydrophilic
hydrophobic
191
where does excess bilirubin migrate to and why
- subcutaneous layer, fat layer
- bilirubin is hydrophobic and so is the subQ layer
192
what system can excess bilirubin cause damage to
central nervous system
193
what does it mean that bilirubin can be photoisomerized
light photons can change the molecular structure
194
why is light a treatment for jaundice
- bilirubin can be photoisomerized
- it changes structure when exposed to light photon, making it hydrophilic
- the excess can then be excreted from the body
