Lesson 4: The Integumentary System Flashcards
1
Q
Epidermis
A
- The outermost and thinnest layer of the skin
- Epi indicates on or over the dermis
- Composed of 5 distinct strata
- Most superficial skin layer
2
Q
Dermis
A
- Deeper and thicker than the epidermis; its the innermost layer of the skin
- Dermis is deep
3
Q
Subcutaneous Tissue or Hypodermis
A
- Layer of fat and connective tissue underneath the epidermis and dermis
4
Q
Functions of Subcutaneous Tissue or Hypodermis
A
- Fat (adipose) tissue in this layer provides insulation and shock absorption
- It serves as a store of energy that can be metabolized should the need arise
5
Q
Stratum Germinativum
A
- Innermost layer of the epidermis
- This is the layer in which new skin cells are produced
- New skin cells “germinate”
6
Q
Keratin
A
- As new cells are produced, they are pushed upward toward the surface of the skin. As they do so, they die, and the cytoplasm of those cells is replaced with this protein
- This keratinized layer of outermost skin is what gives us that tough, flexible, and waterproof protection from the outside world
- Substance that makes up our hair, nails, as well as horns and tusks of other animals
7
Q
Stratum Corneum
A
- The uppermost layer of keratinized skin cells
- Cells of this layer eventually flake off, being replaced by younger cells travelling upward from underneath
- 70-80% of house dust is composed of dead skin
- Think of a bad sunburn, these cells come off in thin sheets refer to as colloquially as peeling
8
Q
Melanocytes
A
- Your skin has a colour and the colour reflects hereditiary factors that influence the amount of a brown pigment (melanin) produced by specialized cells
- More or less have the same number of Melanocytes
- Darker our skin gets is a function of the activity of our melanocytes (the more active melanocytes are the darker skin you have)
- Activity of melanocytes can also be affected by exposure to the sun, more exposure to sun stimulates melanocytes to produce more melanin which increases the darkness of the skin
9
Q
Skin under the Nails
A
- No matter your skin colour overall, the skin under your nails at best is lightly pigmented
- Tells us about the availability of oxygenated blood
- Poorly oxygenated blood or low blood volume can reveal itself through a discolouration of the skin specifically blue-grey appearance of nail beds
10
Q
Cyanotic
A
- Someone with grey- blue nail beds, lips etc..
11
Q
Cyanosis
A
- People with light skin colouration can take on this overall pallor but its observable in the nails regardless of the levels of pigmentation on the back of the hand
12
Q
Vitiligo
A
- Results from a reduction in skin pigmentation that follows the loss of melanocytes
- Most often due to genetic factors
- Degree of pigmentation varies across bodies and can be influenced by other factors
- Pregnant women often experience hormone-related changes in skin colour, increased pigmentation of the areolas
- People with freckles are also familiar with another source of variation in skin colouration, determined by genetic traits. Freckles are a kind of skin lesion
13
Q
Skin Lesions
A
- Involve some variation from the normal structure of tissue
- Often noted by abnormal tissue density or colouration
- Not necessarily a sign of disease
14
Q
Chloracne
A
- Condition characterized by the papules, firm, raised lesions of less than one centimetre in diameter
15
Q
Warts
A
- Another form of this type of skin lesion
- Papules can be found in infectious diseases such as molluscum contagiosum and chicken pox, and non-infectious causes such as eczema and allergic reactions
16
Q
Plaques
A
- Large, raised lesions that are > 1cm in diameter
- While Plaque psoriasis is the most common example of this lesion, plaques can also result from skin infections like ring worm and from the yeast infection tinea
- Plaques can also be found in cases of eczema
17
Q
Plaque psoriasis
A
- Is a condition characterized by abnormally rapid growth of skin that becomes raised and red-silver in appearance
- It can flake off, and be itchy
18
Q
Vesicles
A
- Characterized by small <1cm fluid filled blisters
- Caused by the same virus that gives us chickenpox
- Herpes viruses and Shingles cause similar lesions
- Caused by the build-up of fluid under the epidermis
- Some cases you can find vesicles in eczema and allergic reactions such as poison ivy
19
Q
Pustules
A
- Elevated lesion that is filled with pus such as acne vulgaris
- Specifically observed in the disease smallpox which now has a vaccination
- Can result from allergic reactions and bites of insects
20
Q
Crust
A
- Skin lesion that makes you very itchy
- Referred to as a scab
- Its a raised area with dry blood or exudate (fluid that leaks out of blood vessels)
21
Q
Wheals or Urticaria
A
- Elevated skin lesions commonly called a hive
- It’s a firm, raised area of skin with an irregular shape and a light- coloured centre
- Commonly caused by allergic reactions to food, medications, or insect bites
- Urticaria pigmentosa
22
Q
Macules
A
- Freckles are an example
- Small, flat, discoloured areas of skin
- Some moles are macules and small areas of vitiligo are considered macules as well
- Flat lesion that is small <1cm skin lesions that are different in colour in comparison to surrounding skin