INTEGUMENTARY Flashcards
1
Q
Covering from external environment; protects against UV radiation, dehydration and microorganisms
A
Protection
2
Q
Numerous sensory receptors in the skin
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Sensation
3
Q
Modulating blood flow through skin and the sweat glands
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Temperature regulation
4
Q
When irradiated by UV light, Vitamin D is transformed to its hormonal form (for Ca+ regulation)
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Vitamin D production
5
Q
Small amounts of waste excreted through glands and the skin
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Excretion
6
Q
Sex pheromones produced by the apocrine sweat glands and are involved in the attraction between sexes
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Sexual signaling
7
Q
The skin is made up of two major tissue layers, the
A
Epidermis and the Dermis
8
Q
superficial layer of the skin, consisting of stratified squamous epithelial tissue. Contains Multiple cell layers
A
Epidermis
9
Q
layer of connective tissue; responsible for most of the strength of the skin
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Dermis
10
Q
- a layer of loose connective tissue
- Not part of the skin or the integumentary system, but it does connect the skin to
underlying muscle or bone
A
Subcutaneous tissue, or hypodermis
11
Q
- Stratified Squamous Epithelium
- No blood vessels; receives nutrients and excretes waste products by diffusion to the capillaries of the dermis
A
EPIDERMIS
12
Q
Cells of the epidermis:
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Keratinocytes
Melanocytes
Merkel Cells
Langerhans Cells
13
Q
Epithelial cells containing keratin; provides resistance to abrasion
and water loss
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Keratinocytes
14
Q
Produce the pigment melanin; which contributes to skin color.
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Melanocytes
15
Q
Cells associated with nerve endings; detects light touch and superficial pressure
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Merkel Cells
16
Q
Associated with immune response; Antigen presentation
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Langerhans Cells
17
Q
Newer cells push older cells towards the surface
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(“sloughing off’)
18
Q
From the deepest to the most superficial, the five strata:
A
EPIDERMIS
19
Q
- Single Layer of Cuboidal or Columnar Cells
- Anchored to a basement membrane by hemidesmosomes
- Keratinocyte stem cells undergo mitosis every 19 days
- Melanocytes (melanin producing cells) are seen here
A
Stratum Basale
20
Q
- 8–10 layers of many-sided cell
- Appear “spiny” upon preparation for microscopic observation
- “Spines” are actually desmosomes that come out of cell due to cell shrinkage
- Lipid filled, membrane bound organelles called lamellar bodies form inside
keratinocytes - Langerhans Cells are also present
A
Stratum Spinosum
21
Q
- 2-5 layers of flattened, diamond-shaped cells.
- Presence of kerato-hyaline granules accumulating in the cytoplasm of
keratinocytes - Nucleus and organelles of keratinocytes degenerate; cells die.
A
Stratum Granulosum
22
Q
- Several layers of dead keratinocytes with indistinct boundaries.
- Kerato-hyaline granules have dispersed out of cell; cell appears transparent
- Stratum lucidum is present in only a few areas of the body called Thick Skin
A
Stratum Lucidum
23
Q
palms of the hand, soles of the feet and fingertips
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Thick skin
24
Q
rest of the body
A
Thin skin
25
25 or more layers of dead squamous cells
- Outer layers sheds off due to breaking of desmosomes
- Cornified Cells – dead keratinocytes with protein envelope made of keratin
Stratum Corneum
26
produce and package melanin into vesicles called melanosomes, which will be engulfed by Keratinocytes by phagocytosis
Melanocytes
27
Melanin production is facilitated by the enzyme
tyrosinase
28
Skin color is determined by:
1. Types of melanin produced
2. Amount of melanin produced
3. Size of melanosomes
4. Number of melanosomes
5. Distribution of melanosomes
29
• Involved in Immune Response; Antigen presenting cells
• Only a migrant to the skin (macrophage)
• Also called dendritic cells
• Display a dense nucleus, pale cytoplasm, and long slender processes that radiate out from the cell body into the intercellular spaces between keratinocytes
Langerhans Cell
30
• Scattered among cells of stratum basale
• Abundant in the fingertips and oral mucosa and at the base of hair follicles
• Tonic receptors for sustained light touch and for sensing an object’s texture.
Merkel Cells
31
- Connective Tissue
- Provides Mechanical Support
DERMIS
32
Cells of the Dermis:
1. Fibroblast
2. Adipocytes (few)
3. Macrophages
33
Protein Fibers of the Dermis
1. Collagen (predominant)
2. Elastic
3. Reticular
34
Other Structures in the Dermis:
1. Blood Vessels
2. Hair Follicles
3. Smooth Muscle
4. Glands
5. Lymphatic Vessels
6. Nerve Endings
35
Types of Nerve Endings in the Dermis:
1. Free Nerve Endings
2. Hair Follicle Receptors
3. Pacinian Corpuscle
4. Meissner Corpuscle
5. Ruffini Corpuscle
36
- Superficial layer; immediately next to epidermis
- Forms projections called Dermal Papillae
- Connects with epidermal ridges
- Loose Connective Tissue
- Contains blood vessels that supply nutrients, remove waste products and regulate temperature of the epidermis
Papillary Layer
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- Deep Layer
- Main Layer of the Dermis
- Dense Irregular Connective Tissue
Reticular Layer
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with larger blood and lymphatic vessels lies near the interface of the dermis and the subcutaneous layer.
A deep plexus
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Thermoregulatory Function of the dermis is done and located between both plexuses
arteriovenous anastomoses
40
-Beneath the Dermis
-Also called Hypodermis or Superficial Fascia
- Loose Connective Tissue
SUBCUTANEOUS TISSUE
41
Cells in the Subcutaneous Tissue
1. Adipocytes (Half of the body’s stored lipids are here)
2. Fibroblasts
3. Macrophages
42
Simple nerve endings with no Schwann cell or collagenous coverings (Uncapsulated)
-More complex structures with sensory fibers enclosed by glia and delicate connective tissue capsules (Capsulated)
SENSORY RECEPTORS
43
Uncapsulated Receptors
-tonic receptors for sustained light touch and for sensing an object’s texture.
Merkel cells
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Uncapsulated Receptors
-in the papillary dermis; respond primarily to high and low temperatures, pain, and itching.
Free Nerve Endings
45
Uncapsulated Receptors
-surrounding the bases of hair follicles in the reticular dermis that detects movements of the hairs.
Root Hair Plexuses
46
Capsulated Receptors
- initiate impulses when light-touch or low-frequency stimuli against skin; numerous in the fingertips, palms, and soles
Meissner Corpuscles
47
Capsulated Receptors
- for detection of pressure or firm touch.
-Lamellated (Pacinian) Corpuscles
48
Capsulated Receptors
- collagenous, fusiform capsules anchored firmly to the surrounding connective tissue.
Ruffini Corpuscles
49
ACCESSORY SKIN STRUCTURES
1. HAIR
2. NAILS
3. GLANDS
a. Sweat Glands
b. Sebaceous Glands
50
- is found everywhere on the skin except the palms, the soles, the lips, the nipples, parts of the external genitalia, and the distal segments of the fingers and toes.
HAIR
51
• 5th to 6th week of fetal development – lanugo (unpigmented)
• At Birth – terminal hairs replace lanugo of scalp, eyelids and eyebrows
• Vellus Hairs – shorter, finer hairs that replace lanugo of the rest of the body
• Puberty – Terminal Hairs replaces vellus hair in the body, esp. pubic and axillary regions
Hair Development
52
- Keratinized Structures forming within epidermal evaginations called hair follicles
- Rapidly undergoing keratinization to form the medulla, cortex, and cuticle of a hair root
HAIR
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- Protrudes above the surface of the skin
Hair Shaft
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- Below the surface of the skin
- The base of the ? is called the Hair Bulb
Hair Root
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Layers of the Hair Root and Hair Shaft
1. Medulla
2. Cortex
3. Cuticle
56
- Center, has 2 layers of soft keratin
Medulla
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- Covers Medulla; layers of hard keratin
Cortex
58
- Covers Cortex; 1 layer of hard keratin
Cuticle
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- Tube like invagination of the epidermis that extends into the dermis.
- Hair develops and grows within each
Hair Follicle
60
Layers of the Hair Follicle
1. Dermal Root Sheath
2. Epithelial Root Sheath
- Internal Root Sheath
- External Root Sheath
61
- Smooth muscle inserts on hair follicle and base of epidermis
- When contracting, it pulls the follicle into a more perpendicular position, causing the hair to “stand on end”
- Common response to cold temperatures
Arrector pili muscle
62
- Thin plate consisting of layers of dead stratum corneum cells that contain a very hard type of keratin
- Located on the distal ends of the digits (fingers and toes).
NAILS
63
Proximal portion of nail; covered by skin
Nail Root
64
Distal portion of nail; visible portion
Nail Body
65
Skin that covers lateral and proximal edges of a nail
Nail Fold
66
Holds the edges of the nail in place
Nail Groove
67
– Part of the nail fold that grows onto the nail body
Cuticle
68
– Area of cell division of nails; newly formed cells move distally and become
keratinized
Nail Matrix
69
- visible portion of nail matrix
Lunula
70
GLANDS
Sebaceous Glands
Sweat Glands
71
- Located at Dermis; releases secretions into upper portion of Hair Follicles
- Compound Acinar (alveolar)
- Produces Sebum (rich in lipids)
- Holocrine Secretion
Sebaceous Glands
72
- A.K.A. Sudoriferous Glands
- Two types, eccrine and apocrine
- Despite their name, both use merocrine secretion
Sweat Glands
73
- Most common sweat gland
- Not found in lips, labia minora, tips of clitoris and penis
- Simple, coiled, tubular
Eccrine Sweat Glands
74
Secretory segment produces fluid containing mostly water but also contains the ff:
1. Salts (Sodium Chloride)
2. Ammonia
3. Uric Acid
4. Urea
5. Lactic Acid
75
- Simple, coiled, tubular
- Opens into hair follicles, superficial to sebaceous glands
- Found in axillae, genitalia and around the anus
- Does not help in temperature regulation; active in puberty and suggested to signal sexual activity
Apocrine Sweat Glands
76
Other Skin Glands:
Ceruminous Glands
Mammary Glands
77
– secretes cerumen (earwax); located in external auditory canal
Ceruminous Glands
78
– modified apocrine sweat glands; produces milk
Mammary Glands
79
Protection
-prevents abrasion
Epidermis
80
Protection
-prevents structural strength; prevents tearing
Dermis
81
Protection
- secretions produce environment not suitable for some microorganisms
Glands
82
Protection
– absorbs UV Light
Melanin
83
Protection
– insulation, protection from foreign substances (eyelashes , nostrils) protects from
abrasion (axillary and pubic hair)
Hair
84
Protection
– protects distal portions of fingers and toes; may be used for defense
Nails
85
Protection
reduces water loss, physical barrier against microorganisms
Intact Skin
86
• Receptors for pain, heat, cold and pressure
Sensation
87
• To increase heat loss
• To decrease heat loss
Temperature Regulation
88
– Dilation of blood vessels in the dermis
- Sweat production
To increase heat loss
89
- Constriction of blood vessels in the dermis
- Contraction of the arrector pili muscles causes hair to stand on end
To decrease heat loss -
90
• Skin exposed to ultraviolet light produces cholecalciferol, which is modified in
the liver and then in the kidneys to form active vitamin D.
• Vitamin D increases blood calcium levels by promoting calcium uptake from the
small intestine.
Vitamin D Synthesis
91
• Skin glands remove small amounts of waste products (e.g., urea, uric acid, and
ammonia) but are not important in excretion
Excretion
92
• Apocrine Sweat Glands
Sexual Signaling
93
– injury to a tissue caused by heat, cold, friction, chemicals, electricity, or radiation.
- Classified according to the extent of surface area involved and the depth of the burn
Burn
94
• First Degree
• Second Degree
Partial Thickness Burns
95
• Third Degree Burns
Full Thickness Burns
96
- Involves only damage to Epidermis
- Redness, pain, and slight edema (swelling)
- Sunburn, brief exposure
- Heals without scarring (Approx 1 week)
First Degree Burns
97
- Damages Epidermis and Dermis
- Redness, pain, and slight edema for minimal dermal damage
- Wound appears red for deep dermal damage
- Heals with scarring (Months)
- Epidermis fully regenerates
Second Degree Burns
98
- Complete destruction of Epidermis and Dermis
- Painless because sensory receptors are destroyed
- Skin can only regenerate from the edges
- Skin grafting is necessary
Third Degree Burns
99
– abnormal cell mass
Cancer
100
- Does not spread
•Benign
101
- Metastasized (moves) to other parts of the body
•Malignant
102
- most common type of cancer
•Skin cancer
103
•Skin cancer
What Cells are Involved?
1. Basal cell carcinoma
2. Squamous cell carcinoma
3. Melanoma
104
• Most common skin cancer; Usually arises in sun exposed skin
• Affects cells in the stratum basale. Basal cell carcinomas have a varied appearance
• Slow growing but locally destructive
Basal Cell Carcinoma
105
• Less common
• Affects cells in the stratum spinosum and can appear as a wart like
• Faster-growing, occasionally metastasizes
Squamous Cell Carcinoma
106
• Least common, but most deadly
• Arise from Melanocytes
• Appears black or brown, but also red or pink
• 40% of melanomas develop in preexisting moles.
Melanoma
107
• Early detection is crucial
• Routine examination of the skin and application of the ABCDE rule, which
states the signs of melanoma:
Detection of Melanoma
108
(One side of the lesion does not match the other side)
Asymmetry
109
(Edges are ragged, notched, or burred)
Border Irregularity
110
(Pigmentation is not uniform)
Color
111
(Greater than 6 mm)
Diameter
112
(Changing in size, shape, may bleed, crust, itch or become tender)
Evolving
