Integumentary System Flashcards
1
Q
What are the two principal parts of the Integumentary System?
A
Epidermis and Dermis
2
Q
The superficial, thinner layer composed of epithelial tissue
A
Epidermis
3
Q
The deeper, thicker layer composed of dense irregular connective tissue
A
Dermis
4
Q
What are the specific functions of the skin?
A
Thermoregulation Protection from external environment Cutaneous sensation Excretion Synthesis of vitamin D Reservoir for blood Absorbs substances
5
Q
Excretion: what does sweat eliminate?
A
some water, salts, CO2, ammonia, urea
6
Q
What are some characteristics of thermoregulation?
A
Evaporation of sweat cools the skin
Increased blood flow to the skin promotes heat loss by radiation
Hair traps heat, thereby reducing heat loss in cold temperature
7
Q
The epidermis is composed of?
A
Keratinized stratified squamous epithelium
8
Q
What are the four major types of cells of the Epidermis?
A
Keratinocytes
Melanocytes
Langerhans Cells
Merkel Cells
9
Q
What is keratin?
A
tough, fibrous protein that waterproofs the skin
10
Q
What does keratin do?
A
helps protect the skin and underlying tissues from heat, microbes, and chemicals
11
Q
Keratinocytes (a layer of the epidermis) are formed when?
A
New cells produced by mitosis become filled with keratin.
12
Q
What produces the pigment melanin?
A
the organelle melanosome
13
Q
What is melanin?
A
A brown-black pigment that contributes to skin color and absorbs damaging ultraviolet light
14
Q
Projections from _________ extend between keratinocytes, and do what?
A
melanocytes
They transfer melanin granules to them
15
Q
What do the melanin granules do?
A
Cluster over the nucleus on the side toward the skin surface, shielding nuclear DNA from UV light.
16
Q
What synthesize melanin from the amino acid tyrosine in the presence of the enzyme tyrosinase?
A
Melanosomes of melanocytes
17
Q
Melanosomes of melanocytes synthesize melanin from the amino acid _____ in the presence of the enzyme ______
A
Tyrosine
Tyrosinase
18
Q
What participates in immune responses to microbes that invade the skin (immune cells)?
A
Langerhans Cells
19
Q
Langerhans cells are a type of what kind of cell?
A
Dendritic
20
Q
What resides in the deepest layer of the epidermis where they contact the flattened processes of tactile discs?
A
Merkel Cells
21
Q
What are the tactile discs, a type of sensory cell, the merkel cells contact called?
A
Merkel discs
22
Q
What functions in the sensation of touch?
A
Merkel cells and tactile discs
23
Q
What are they layers of the epidermis?
A
Stratum Corneum Stratum Lucidum Stratum Granulosum Stratum Spinosum Stratum Basale
24
Q
What is the deepest layer of the epidermis?
A
Stratum Basale
25
What is the Stratum Basale made up of?
Mostly keratinocytes, a few melanocytes and Merkel cells
26
Keratinocytes have what type of filaments? and they are called?
Intermediate filaments
| Tonofilaments
27
What are tonofilaments composed of?
A protein that will later form keratin
28
What has 8-10 layers of keratinocytes and a few Langerhans cells?
Stratum Spinosum
29
Older cells in the stratum spinosum start to?
Flatten
30
True or False
| Cells in the stratum spinosum are still alive and some divide
True
31
3-5 layers of flattened keratinocytes and is a transition between living cells and the more superficial dead cells
Stratum Granulosum
32
In the stratum granulosum, what release a waterproofing lipid solution?
Lamellar granules
33
What is stratum granulosum filled with?
Granules of keratin
34
These are only found on fingertips, palms of hands, soles of feet.
Stratum Lucidum
35
What has 3-layers of flattened dead keratinocytes filled with keratin?
Stratum Lucidum
36
What is the most superficial layers of the epidermis that has 25-30 layers of flattened, dead cells?
Stratum Corneum
37
What provides waterproofing in the stratum corneum?
Between cells, lipids for lamellar granules
38
This layer of cells in the epidermis, interior of cells contains mostly keratin. The cells are continuously sloughed off and replaced by cells from deeper strata.
Stratum Corneum
39
What is dense irregular connective tissue that contains collagen and elastic connective tissue?
Dermis
40
What are the contents of the dermis?
Blood vessels
Nerves
Glands; sebaceous (oil) and sudoriferous (sweat)
Hair follicles
Arrectores pilorum muscles (singular is arrector pili)
41
What are the two components of the dermis?
Papillary region
| Reticular region
42
What is the superficial part of the dermis?
Papillary region
43
What greatly increase the surface area of the papillary region? Why?
Dermal papillae
Gives better adhesion to epidermis
More surface area for diffusion to and from epidermis
44
What receptors are present in the papillary region of the dermis?
Touch corpuscles (Meissner corpuscles) for touch/light touch
45
What are touch corpuscles?
Free nerve endings with no apparent structural specialization that give rise to sensation of warmth, coolness, pain, tickle, itch
46
What consists of dense, irregular connective tissue containing bundles of collagen and some elastic fibers?
Reticular region of the dermis
47
The space between the fibers of the dermis are occupied but what?
```
Adipose cells
Hair follicles
Nerves
Sebaceous (oil) glands
Sudoriferous (sweat) glands
```
48
The combination of collagen and elastic fibers in the reticular region of the dermis provides?
the skin with strength, extensibility, and elasticity
49
What is the hypodermis?
Subcutaneous layer
50
What is the subcutaneous layer composed of ?
Areolar and adipose tissues
51
What does the subcutaneous layer contain?
Fat
Fibers that attach the dermis to deeper tissues
Larger blood vessels
Sensory receptors: Pacinian corpuscles (lamellated corpuscles)
52
What do Pacinian corpuscles sense?
Pressure
53
What are the epidermal ridges commonly called?
Fingerprints
54
What develops during the third and fourth fetal months as the epidermis conforms to the contours of the underlying dermal papillae of the papillary region?
Epidermal ridges (Fingerprints)
55
What do fingerprints do?
Increase the grip by increasing friction
56
What open on the tops of the epidermal ridges as sweat pores forming a pattern on smooth objects that are touched?
Ducts of sweat glands
57
What three pigments of varying amounts is the color of skin due to?
Melanin
Carotene
Hemoglobin
58
What determines the amount and expression of melanin and carotene?
Genetics
59
True or False
| The number of melanocytes varies among different races
False
60
Exposure to UV light does what to the melanosomes?
the enzymatic activity
61
What gives the skin a tanned appearance and further protects the body against UV radiation?
Increased melanin production.
62
What is a yellow-orange pigment that is a precursor to vitamin A?
Carotene
63
What is used to synthesize pigments needed for vision?
Carotene
64
What causes the skin to appear pink?
when there is little melanin or carotene present, which allows the hemoglobin in the capillaries of the dermis to be expressed
65
What are the accessory structures of the skin?
Hair
Nails
Skin glands
66
In the dermis, what secrets sebum (oil) into a hair follicle?
Sebaceous glands
67
In the dermis, what duct extends through the epidermis?
Sweat glands
68
What is the superficial portion of the hair?
The shaft
69
What are the three layers of the hair shaft?
Medulla
Cortex
Cuticle
70
What is the downward continuation of the epidermis?
The external root sheath surrounding the root of the hair
71
What is hair composed of?
Dead, keratinized cells bonded by proteins
72
Where is the root of the hair located?
In the dermis
73
How does the hair grow?
Division of cells at the base of the hair follicle, new cells produced by mitosis in the hair matrix push the growing hair through the pilary canal.
74
What is the enlargement at the base of the hair follicle?
Bulb
75
What is the germinal layer of cells within the bulb called?
the matrix
76
Where does the matrix, in the bulb at the base of the hair follicle, arise from?
It is the site of what?
The stratum basale.
| Site of cell division that produces the hair
77
What is associated with the hair?
Sebaceous (oil) glands
A bundle of smooth muscle called the arrector pili
Hair root plexuses
78
What causes goose bumps?
Autonomic nerve endings stimulate arrectores pilorum muscles to contract which causes goose bumps
79
A bundle of smooth muscle called the arrector pili helps regulate what?
Temperature and makes one look larger
80
What is the hair root plexus composed of?
Groups of dendrites and nerve fiber endings that form network around a hair follicle.
81
What does the hair root plexus act as?
A receptor to generate nerve impulses when hair shafts are moved.
82
In the category of hair, what acts like a fulcrum?
The shaft of the hair root plexus
83
In the category of hair, what is sensitive to touch, and movement of the hair shat?
Hair root plexus
84
What does each nail consist of?
Nail body
Free Edge
Nair root
85
What portion of the nail is visible?
Nail body
86
Why does the nail body appear pink?
Blood flowing through underlying capillaries
87
What is the whitish, crescent-shaped area of the proximal end of the nail?
The lunula
88
What are nails made of?
Tightly packed, hard, keratinized epidermal cells
89
What is the epithelium deep to the nail root called?
The nail matrix
90
How does the nail produce growth?
Cell of the nail matrix divide mitotically producing growth
91
What cells of the nail matrix are transformed into nail cells?
Superficial cells
92
The older harder cells of the nail matrix are pushed along the what toward the fingertip?
Stratum basale
93
What is sebum?
An oily substance that:
Keeps hair from drying
Prevents excessive evaporation of water from the skin
Inhibits growth of some bacteria
94
What are the two main types of sweat glands?
Eccrine sweat glands (Merocrine sweat glands)
| Apocrine sweat glands
95
Where are the eccrine sweat glands (Merocrine sweat glands) found?
Found most places on the skin, function in thermoregulation
96
Where are apocrine sweat glands found?
Found in association with hair that develops at puberty
97
In what condition do the keratinocytes divide and move more quickly than normal from the stratum basale to the stratum corneum and are shed prematurely
Psoriasis
98
In Psoriasis what forms flaky, silvery scales at the skin surface most commonly on knees, elbows, and scalp (dandruff).
Immature keratinocytes that make an abnormal keratin
99
What are the three common forms of skin cancer?
Basal cell carcinomas (most common)
Squamous cell carcinomas
Malignant melanomas (least common, but most life-threatening)
100
What is the inherited inability of an individual to produce melanin, it is missing from their hair, eyes, and skin?
Albinism
101
In most cases, what is the cause of albinism?
The melanocytes are unable to synthesize tyrosinase
102
What is the partial or complete loss of melanocytes from patches of skin?
Vitiligo
103
What may be an autoimmune disorder in which the melanocytes are attacked and killed? There is also an apparent genetic link.
Vitiligo
104
What is cyanosis due to?
Hemoglobin that is depleted of oxygen looks deep, purplish blue.
105
Erythema is caused by engorgement of capillaries in the dermis with blood due to?
```
Skin injury
Exposure to heat
Infection
Inflammation
Allergic Reaction
```
106
What is Striae?
A form of scarring of the skin caused by tearing of the dermis. First appears as purple or reddish lines, but later fade to a lighter color.
107
What is Strae due to?
Result of rapid stretching of the skin due to rapid growth of puberty, weight gain, or pregnancy.
108
What can cause Alopecia?
Againg
Endocrine disorders
Chemotherapy
Skin diease
109
Inflammation of the skin characterized by redness, itching, and swelling, and caused by exposure of the skin to chemicals that bring about an allergic reaction
Contact Dermatits
110
What are the two types of wound healing?
Epidermal wound healing
| Deep wound healing
111
What occurs following superficial wounds that affect only the epidermis and returns to normal function?
Epidermal wound healing
112
What occurs when an injury extends to the dermis and subcutaneous layer? Loss of some function and development of scar tissue is the rule.
Deep wound healing.
113
What are the steps of epidermal wound healing?
Basal cells at the margins of the wound break contact with the basement membrane and migrate
When basal cells contact each other, they stop migrating (contact inhibition)
Mitosis of basal cells is stimulated
Keratinocytes move up to form the more superficial layers
114
What are the stages of deep wound healing?
Inflammatory Phase
Migratory Phase
Proliferative Phase
Maturation Phase
115
What are the steps of the inflammatory phase of deep wound healing?
A blood clot forms and binds wound edges
Blood flow is increased, blood vessels become more permeable
WBCs and mesenchymal cells migrate to the area
116
What are the steps of the migratory phase of deep wound healing?
Epithelial cells migrate beneath the scab and bridge the wound
Fibroblasts migrate into the wound and begin to produce collagen fibers
117
What are the steps of the proliferative phase of deep wound healing?
Growth of epidermal cells beneath the scab
Increase in the amount of collagen
Regeneration of blood vessels
118
What are the steps of the maturation phase of deep wound healing?
Scab is lost
| Collagen fibers become more organized, fibroblast numbers decrease, blood vessels are restored to normal.
119
Define- Tissue damage caused by excessive heat, electricity, radioactivity, or corrosive chemicals that destroy (denature) the proteins in the skin cells
Burn
120
What degree of burn involves only the epidermis, characterized by mild pain and erythema, but no blisters?
First degree burn
121
How long will it take a first degree burn to heal?
A few days and may be accompanied by flaking or peeling
122
What degree of burn destroys a portion of the epidermis and possibly parts of the dermis, characterized by pain, redness, blister formation, and edema? Some skin function are lost.
Second degree burns
123
How long does it take second degree burns to heal?
in a few (3-4) weeks, if there is no infection, scarring may result
124
What degree of burn destroys a portion of the epidermis as well as the underlying dermis and associated structures?
Third degree
125
Which degree of burn is marked edema, and the burned region is numb due to destruction of sensory nerve endings? Also termed full-thickness burn
Third degree
126
Which degree of burn are skin functions lost?
Third degree
127
An area where skin has been scraped away
Abrasion
128
A superficial fungal infection of the skin of the foot
Athlete's foot
129
A collection of serous fluid within the epidermis or between the epidermis and dermis, due to short-term but severe friction
Blister
130
An area of hardened and thickened skin that is usually seen in palms and soles, and is due to persistent pressure and friction.
Callus
131
An inflammation of the skin characterized by patches of red, blistering, dry, extremely itch skin
Eczema
132
Medication applied to the skin surface, rather than ingested or injected
Topical
133
Mass produced by uncontrolled growth of epithelial skin cells; caused by a papillomavirus
Wart
134
Condition of excessive body hair
Hirsutism
135
Fine, nonpigmented, downy hairs that cover the body of the fetus
Laguno
136
Coarse, heavily pigmented hair; includes hair of the head, eyebrows, eyelashes, and hair that develops as a secondary characteristic.
Terminal Hairs
137
Short, fine, pale hairs that develop on most of the body during childhood
Vellus hairs
