Integumentary System Flashcards
1
Q
What is the integumentary system composed of?
A
- Epidermis
- Dermis
- Subcutaneous tissue
2
Q
What is the largest organ in the body?
A
- Skin
- compromising up to 15% of total body weight
- Surface area ranges between 1.2 to 2 square meters
3
Q
Functions of the Integumentary System
A
- Protection
- Sensory reception
- Temperature regulation
- water and salt excretion
- water loss prevention
- metabolic regulation
- immurial defense mechanisms
4
Q
Selectively permeable membrane
A
- Skin
- which prevents water loss, provides protection and regulates the body temperature
5
Q
What does the integument provide protection from?
A
- Injury and trauma
- UV light
- Microbes
- Toxin radiation
- chemicals
6
Q
Sensory reception
A
- Pain
- Heat
- cold
- pressure
7
Q
specialized sensory nerve endings
A
capable of detecting slight variations in temperature, pressure, vibration and texture
8
Q
nociceptors
A
nerve cells specialized to precieve damage to the skin which register a positive pain response when stimulated
9
Q
Temperature regulation
A
- Erect Hairs
- Sweat
10
Q
Evaporative Cooling
A
when the body is too warm, excessive perspiration evaporates on the skin surface
11
Q
vasodilation
A
- when the body is too warm, blood vessels of the integument dilate
- this allows more blood to flow through the issues giving off heat along the way; thus lowering the bodys temperature
12
Q
vasoconstriction
A
when the body is too cold, blood vessels of the integument thus preventing blood flow to the outer tissues and conserving body heat
13
Q
Integument functions in salt excretion
A
integument is water resistant. water along with salts and urea, can be actively secreted through sweat glands
14
Q
trasepidermal water loss
A
small amounts of interstitial fluids can escape through the skins surface
15
Q
perspiration
A
- “sensible” or “insensible”
- an estimated 500 mL of water is secreted through the integument each day
16
Q
what is done to prevent additional water loss?
A
the water that is secreted mixes with sebum to produce a oily, slightly acidic, barrier which prevents too much water from escaping
17
Q
what causes the formation of Vitamin D?
A
- Integument
- vitamin D is essential for calcium absorption from foods we eat
18
Q
Cholecalciferol
A
exposure to UV radiation triggers cells of the integument to be produced
19
Q
calitriol (vitamin d)
A
cholecalciferol travels through the circulatory system to the kidneys where it is synthesized to make vitamin d
20
Q
what is essential for proper bone development?
A
- calcium
- phosphorus
21
Q
what is important to promote calcium and phosphorus absorption through the small intestines?
A
vitamin d
22
Q
how much of exposure to the sun is sufficient to obtain enough vitamin d to sustain the bodys needs for calcium and phosphorus?
A
15 minutes
23
Q
Langerhan’s Cells or Epidermal dendritic cells
A
possesses specialized cells of the immune system
24
Q
phagocytosis
A
epidermal dendritic cells or langerhans cells specialized to destroy pathogens that have invaded the outer layers of the integument
25
layers of strata of the epidermis superficial to deep
- Stratum Corneum
- Stratum Lucidum
- Stratum Granulosum
- Stratum Spinosum
- Stratum Basle
26
two distinct layers of the skin
- Epidermis
- Dermis
- both lie on an underlying layer called the subcutaneous tissue or hypodermis
27
thickest integument
| thinnest integument
- thickest integument: Back. ranges up to 1/2 cm in thickness
- thinnest integument: eye lid. as thin as 1/2 mm
28
what is the epidermis comprised of?
- Keratinized
| - stratified squamos epithelium
29
Epidermis
- outermost layer of the integument.
| - the visual portion of the skin
30
is the epidermis vascular
- No
- does not contain blood vessels
- contains nerves and nerve endings
31
what happens in the deepest layers of the epidermis?
some cells undergo mitosis and migrate to the outermost layers where they become desiccated, convert to keratin and eventually slough off
32
how long is the process of skin cells birth to slough?
- 30 days
| - epidermis is constantly being replaced
33
Stratum Basale
deepest layer of the epidermis and is made up of a single layer of cuboidal/columnar cells called keratinocytes
34
keratinocytes
- stem cells that divide continuously throughout life
| - produce structural protein keratin which lends rigidity and insolubility to the cells cytoskeleton
35
melanocytes
- deepest levels
| - produce dark pigment: melanin
36
melanin
responsible for skin color as it accumulates around the nucleus of the keratinocyte and shields it from the harmful effects of UV radiation
37
albinism
geneti recessive condition which involves a mutation to the gene responsible for melanin production in the melanocytes
38
individuals lacking melanin....
- exhibit a lack of skin pigmentation
| - greater susceptibility to skin cancer since they lack melanin to protect the DNA within the nucleus of keratinocytes
39
stratum spinosum
- several layers of keratinocytes found superficial to the stratum basale
- every time the cells of the stratum basale divide, the daughter cell is pushed upward
40
keratinocytes of the stratum spinosum
-non-dividing
41
Langerhan's Cells in the stratum spinosum
- immunological cells capable of destroying pathogens that invade the epidermis
- been shown to destroy epidermal cancer cells
42
stratum granulosum
- consists of 3 to 5 layers of flat cells
| - cells begin to die
43
keratinization
nucleus and organelles of the cells in the stratum granulosum disintegrate and the cells fill with the structural protein using this process
44
stratum lucidum
- thing, translucent layer of cells which lies superficial to the stratum granulosum
- exits in areas of the body with very thick skin (palms, soles)
45
keratin on palms and soles
- very thick
| - forms papillary ridges that occur in characteristic patterns (fingerprints & toe prints)
46
Stratum corneum
- most superficial
| - 20-30 layers of dead keratinized cells called corneocytes
47
cell migraation from stratum basale to stratum corneum
- 2 weeks long
| - remain in the stratum corneum for an additional 2 weeks before they shed
48
dermis
- layer deep to the epiermis
- composed of
1. dense irregular connective tissue which contains blood vessels and nerves
2. 80% of the thickness of the skin
3. many collagen fibers, hair follicles, and sweat glands
49
two strata of the dermis
- papillary layer
| - reticular layer
50
papilary layer
-lies adjacent to the epidermis and possesses raised projections called dermal papillae
51
dermal papilllae
- contain sensory nerve endings
| - capillary networks, which supply nutrients to the superficial layers of the epidermis
52
reticular layer
- extends from the papillary layer to the underlying subcutaneous tissue
- possesses majority of accessory structures associated with the dermal layer of integument including
1. blood vessels
2. nerves
3. sweat glands
4. hair follicles
53
large bundles of collagen and elastic fibers
- pass through the dense irregular connective tissue in the dermis
- stretch from the reticular layer of the dermis to the underlying subcutaneous tissue and give the skin its strength and elasticity
54
collagen fibers of the dermal layer
- oriented into parallel bundles that resist stress along lines of movement called lines of cleavage
- important clinical consideration, surgical incisions should always be made parallel to lines of cleavage
55
subcutaneous tissue
- also called the hypodermis
- lies deep to the dermis
- made up of loose connective tissue with an abundance of adipose (fat) tissue
56
what course through the subcutaneous tissue on their way to the dermis?
- blood vessels
| - nerves
57
subcutaneous fat
in certain locations of the body, adipose connective tissue predominates
58
adipose tissue
- more abundant in females than males
| - provides insulation, conceives body temperature and acts as a shock absorber
59
distribution of subcutaneous fat
- Females: accumulate fat primarily in the breasts, hips, thighs and gluteal regions
- Males: accumulate fat in the arms, abdomen, and lower back
60
subcutaneous injections
- subcutaneous tissue contains a rich nerve and blood supply
- injections are done because the rich vascular network found in the hypodermis allows for the rapid absorption of the medication
61
accessory organs of integument
- hair
- exocrine glands
- nails
62
3 types of hair
- Lanugo hair: develops on fetus during the last trimester. very fine and lacks pigmentation
- Vellus hair: replaces lanugo after birth and is the lightly pigmented hair found on most parts of the body
- Terminal hair: longer pigmented hair found on the scalp, eyebrows and lashes
63
hair follicles
- derived from specialized invaginations of stratum basale and stratum spinosum layers
- contain hairs which form by papillae undergoing mitosis
- elongates at the rate of 1 cm per moth as each cellular division pushes the hair toward the surface
64
Hair Shaft
Hair Root
Hair Papillae
- Hair Shaft: portion of hair that extends through the surface to the epidermis
- Hair root: located within the follicle internal to the skins surface
- Hair papillae: located at the base of the hair bulb and contains nerves and blood vessels which supply the dividing cells of the matrix
65
Alopecia
- thinning hair
- often due to the androgen testosterone
- excess testosterone accumulates in the body and is converted to DHT by the enzyme 5a reductase
- accumulation of DHT blocks the blood vessels entering the hair papillae and results in premature death of hair
66
3 stages of hair growth
1. Anagen: last from 18 months to 7 years. active phase where cells of matrix are rapidly dividing
2. Catagen: lasts from 3-4 weeks and is a period when cellular division has stopped
3. Talogen: lasts 3-4 months and is a resting period when the hair is shedding
67
Exocrine glands
2 types
1. sweat glands
2. sebaceous glands
- serve to eliminate water and excrete waste products
- help regulate bodies temperature by evaporative cooling and provide chemical protection from pathogenetic bacteria
68
sebaceous glands
oil producing glands that produce oil from the disintegration of some glad cells
69
how do sebaceous glands work?
-a duct passes the lipid secretion called sebum into the neck of the hair follicles. the waxy sebum prevents desiccation of the hair follicle and contains bacterial properties that prevent infection
70
folliculitus
localized inflammation of a hair follicle caused by bacterial infection
71
arrector pili muscles
- smooth muscles that extend from hair follicles to the dermal-epidermal junction
- contraction of the muscles due to cold weather causes hairs to stand erect
- traps a layer of air within the hairs which acts as an insulator to keep heat inside the body
72
sweat glands
- secretion part in the dermis or subcutaneous layer and have a coiled secretory portion which produces a watery material mixed with sodium and chloride ions and nitrogenous wastes
- upon autonomle stimulation the sweat glands contract forcing the watery secretions up the sweat gland duct which leads to the surface of the epidermis where it exits at the sweat pore
73
two types of sweat glands
- merocrine sweat glands
| - apocrine sweat glands
74
merocrine sweat glands
- more numerous (3-4 million) and can be found throughout the entire body. highly concentrated on the palms, soles of the feet and forehead
- produce watery secretion containing salt urea and iactic acid (which produces a slightly acidic pH on the skins surface)
75
apocrine sweat glands
- produce more viscous secretion that contains proteins and lipids that are released into the hair gland
- secretions are often consumed by bacteria leading to body odor
- located in the axillary region (arm pit), inguinal region and around the nipples
76
nails
- protective structures of hard keratin located at the tips of the fingers and toes
- arise from specialized cells of the epidermis and serve to protect the distal ends of the fingers and toes
- epidermal cells that form the nail are densely packed and cemented together with parallel fibers of keratin
77
nail bed
nail matrix
nail root
- nail bed: skin underlying the nail and contains only the deeper growing layers of the epidermis
- nail matrix: actively growing portion of the nail
- nail root: modified epithelial cells within the matrix divide continuously which results in the elongation of the nail from here, toward distal free edge
78
First degree burns
- involve damage to the epidermis and are usually caused by sun exposure
- characterized by swelling (edema), redness (rubor) and mild to moderate pain (dolor)
- Scaring following a first degree burn is normally not observed
79
Second degree burns
- damage to the epidermal and dermal layers and present with blistering in addition to the same symptoms of 1st degree burns
- more severe symptoms and healing time is delayed 2-4 weeks
- permanent scaring can result from second degree burns
80
third degree burns
- damage to the epidermis, dermis and subcutaneous tissues
- caused by exposure to corrosive chemicals, scalding water and fire
- dehydration and nosocomial infecting are major concerns. skin arafting procedures are often necessary for treatment
