Chapter 3- integumentary system Flashcards
(61 cards)
1
Q
What are the 5 functions of the skin?
A
- Thermoregulation = sweating and blood flow regulation
- Protection = keratin, sebum, melanin, sweat
- Sensation = tactile and thermal
- Excretion/absorption = some water loss, lipid soluble substances
- Vitamin D synthesis = requires UV simulation
2
Q
What is an organ?
A
consists of a group of tissues working together to perform certain functions
3
Q
What is the epidermis?
A
- stratified squamous epithelia (4-5 layers -strata- of distinct cell types)
- surface consists dead skin cells packed with keratin
- lacks blood vessels
- sparse nerve endings for touch and pain
4
Q
What are the 2 main cell types of the epidermis?
A
- Keratinocytes- main cell type found here
-produce keratin
-provide structure to skin, hair, nails
-water-proof (protect)
-keratinized tissue=dry
nonkeratinized = wet - Melanocytes- produce pigments eumelanin / phenomenon, giving skin and hair its colour
-protects from harmful UV rays
-constant cell division
5
Q
What are merkel cells?
A
small amount of these
- sense of touch
- associated with underlying nerve fibers
6
Q
what are langerhans cells? (dendritic cells)
A
- macrophages
- originate in bone marrow
- protect against pathogens and toxins
- allert immune system
7
Q
What are the 5 layers of the epidermis? Bottom (from basement membrane) to top:
A
- Stratum Basale = stratum germinativum
- single layer of cuboidal or columnar stem cells
- sitting on top of basement membrane
- continuous production of keratinocytes - Stratum Spinosum = against stratum basale
- many (~10) layers of keratinocytes
- upper layer of cells become flattened and lose capacity to divide
- produce lots of keratin
- langerhans found here
- thickest layer - Stratum Granulosum = middle layer
- 3-5 layers of flat keratinocytes undergoing apoptosis (cell death)
- no nutrients from blood vessels therefore die
- secrete substance that acts as waterproofing agent - Stratum Lucidum = found only on thick skin
- consists of few rows of flattened keratinocytes - Stratum Corneum = outermost layer
- many layers of dead keratinocytes (cells completely filled with keratin)
- protect against abraison and penetration
- make skin waterproof
**Study diagram
8
Q
The stratum corneum becomes prominent in what skin type and why?
A
- thick skin (fingertips, feet soles, etc)
- lots of abrasion is expected
9
Q
What is the life cycle of a keratinocyte?
A
- 40 days
- mitosis of stem cells
- new cells form –> older ones pushed to surface
10
Q
How does dander differ from dandruff?
A
dander = dead keratinocytes that fall off dandruff = clumps of cells held together by sebum
11
Q
What is psoriasis?
A
- skin disorder of epidermis
- disruption in life cycle of keratinocytes (cells divide more quickly)
- sheds in 7-10 days
- treatment decreases rate of cell division
12
Q
What 3 pigments give skin its colour?
A
- Hemoglobin = blood pigment (light complexions to look pink or blue)
- Melanin = pigment produced by melanocytes (increased in people exposed to more UV)
- Carotene = yellow-orange pigment from food that builds up in the skin
13
Q
How is colour produced in the skin?
A
- melanocyte can be stimulated to produce more melanin = when has UV
- melanin in melanocytes disperses between keratinocytes
- protects nuclei from further UV exposure
- skin lightens (tan leaves) as these keratinocytes are sloughed off at skin surface
14
Q
What is cyanosis?
A
- blueness of skin resulting from lack of oxygen
- often in newborns, lips and fingernails
15
Q
What is erythema?
A
- abnormal redness of skin
- increased blood flow to the skin
- anger, exercise, embarassment
16
Q
What is erythema migrans?
A
lyme disease
17
Q
What is erythema toxicum?
A
common generalized rash of newborns
18
Q
What is pallor?
A
little blood flow that white colour of dermal collagen shows through
- raynauds syndrome
- episodic vasoconstriction of small digital arteries with exposure to cold
19
Q
What is jaundice?
A
yellowing of the skin and whites of eyes
- due to high levels of bilirubin in the blood
- generally comes with liver problems too
20
Q
What is hemotoma?
A
mass of clotted bloo showing thru the skin
- bruising (blood clotting) is subject to gravity
21
Q
What is the dermis?
A
- layer of connective tissue
- middle layer of the skin
- supplied with blood vessels, glands, and nerve endings
- hair follicles and nail roots found here
22
Q
What is the papillary region and where is it found?
A
- interacts with epidermis thru dermal papillae and epidermal ridges
-contains circulatory vessels and nerves that supply the epidermis
Location = boundary between the dermis and epidermis
23
Q
What is the reticular region and where is it found?
A
- toughest layer of the skin containing thick collagen bundles producing cleavage lines, contains blood vessels and nerves and other accessory structures
Location = most of the dermis
24
Q
What makes up cleavage lines?
A
think bundles of collagen in dermis
25
What produces stretch marks?
stretching of skin from obesity/pregnancy can tear elastic fibres
26
What 2 structures from friction ridges?
result from epidermal ridges/dermal papillae
| - fingerprints
27
Doctors want to cut with or against cleavage lines?
incisions ALONG these lines heal quicker then those that go AGAINST these cleavages
28
What is the hypodermis and where is it found?
| Main functions?
- innermost layer of skin
- subcutaneous layer
- deep to the integument
-areolar and adipose CT
Function- protect underlying structures, stores energy, and thermal insulation
29
What is hair and where does it grow?
- slender filaments of keratinized cells
- grow from follicles in dermis or hypodermis
- almost everywhere except (lips, nipples, part of genitals, palms, parts of fingers and toes)
30
Part of hair that consists of connective tissues, nerves and blood vessels below the follicle that supports the keratinocytes
Hair papilla
- hair matrix within papilla responsible for producing new hair
31
a swelling at bottom of follicle filled with dividing keratinocytes
hair bulb
32
involuntary smooth muscle attached to hair shaft
arrector pili
33
In a cross section of hair - this contains cells with soft keratin- formed by cells closest to the hair matrix
medulla
34
in a cross section of a hair- this contains cells with hard keratin- formed by cells near the edge of the hair matrix
cortex
-also contains pigments for hair colour
35
in a cross section of a hair- this contains cells that contain hard keratin, formed by cells at the edge of the hair matrix
cuticle
36
What type of hair is fine, downy, unpigmented and usually disappears at birth?
lanugo
37
This type of hair replaces hair after birth and is finer and unpigmented
vellus
38
What structure assists in our "hair standing up" in response to cold or frightened
arrector pili muscles
39
What is a sebaceous gland and where is it located?
- an oil gland that secretes sebum (antibacterial properties)
Location - nearly always connected to hairs
40
this type of gland secretes sweat and are simple, coiled tubular glands
sudoriferous
41
What 2 components make up sudoriferous glands?
| Which one smells and which one doesn't?
1. Apocrine - pubic and axilla - part of cell secreted into hair follicle (can smell)
2. Merocrine - more common, all over body and none of cell is secreted (no smell)
42
These modified sweat glands trap dust, small particles and have antibacterial properties, often located in the ear
ceruminous glands
43
What is cerumen?
earwax
44
This gland is a modified apocrine sweat gland that produce a rich secretion
mammary glands
| nipples
45
this is the hard keratin proteins that make nail
nail plate
46
this is a fold of skin that protects nail matrix
cuticle
47
this lies beneath the nail plate and capillaries here give nails pink colour
nail bed
48
this structure produces the nail plate and small fold of epidermis (visible as lunula) - contains nerves, blood vessels and lymphatics
nail matrix
49
What gives the appearance of wrinkles when aging?
- elasticity and collagen in dermis decerases
| - epidermis gets thinner and harder to repair
50
this is a common fungal infection of the skin that is common in children
ring worm
51
this is a fungus that causes itching, redness, and cracking, thrives in warm moist environment
athletes foot
52
this is a local growth in the skin that is caused by HPV infection, usually disappearing with time
warts
53
this is a disease of the hair follicles of the face and chest (sebaceous glands are elevated by hormone levels)
acne
54
this is a general term for many types of skin inflammation (dermatitis)
when the barrier of the skin doesn't function properly
eczema
55
what layer of the skin is affected by a first degree burn?
involves only epidermis
56
what layer/layers of the skin affected by second degree burns?
epidermis and part of dermis
57
what layer/layers of the skin affected by third degree burns?
epidermis, dermis, and some underlying tissues
58
What is skin cancer?
uncontrolled growth of certain cells in the integument
- usually isolated to upper regions of skin so detected early
- overwhelms melanocytes
59
this type of skin cancer occurs from sun-exposed regions and rarely spreads to other regions (rarely fatal)
basal cell carcinoma
60
this type of skin cancer is fairly common and can spread more easily, found on lips or the ears
squamous cell cercinoma
61
this type of skin cancer is the least frequent and spreads the easiest, also the most serious (asymmetrical, irregular and border)
malignant melanoma
