Skin disease Flashcards
What system is the skin a part of
Th integumentary system
Name the largest organ in the body
skin
What are appendages
Hair and nails
What are the functions of normal skin
- Flexible mechanical barrier
- Temperature control
- Immune functions
- Protection versus UV light
- Vitamin D metabolism
- Nerve endings
- Aesthetics
- Absorption
What do we mean by the skin acting as a barrier
- It prevents entry of infectious agents
- Controls loss of fluid from the body
- Waterproofing
How do the skin control temperature
- Blood vessels
- Sweet glands
- Hairs
How do blood vessels help control temperature
Vasodilation and vasoconstriction changes temperature
How does har on the skin help control temperature
pilirection holds a layer of air next to the skin raising the body temp
Name the cell that helps protect us from UV
Melanocytes
What do melanocytes do
They secrete melanin which protects us from UV damage
What do nerve endings in the skin detect
- Heat
- Cold
- Vibration
- Denture touch
- Deep pressure
- Pain
Name the different layers of the skin
- Epidermis
2. Dermis
What is the epidermis
A waterproofing and barrier to infection
How many layers make up the epidermis
5 Layers
What is the dermis
It is where the appendages to the skin are found
Name the 5 laters of the epidermis starting with the outermost layer
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum Spinosum
- Stratum basale
What is found under the dermis?
Hypodermis
what is the hypodermis
A subcutaneous adipose tissue that acts as an attachment to underlying structures
Name the cells found in the skin
- Basal Keratinocytes
2. Melanocytes
Where are Basal Keratinocytes found
In the stratum basale layer
What happens in the stratum basale layer
It is the main site for the generation of new keratinocytes
What are keratinocytes
Stem cells
What is the function of keratinocytes
Keratinocytes needed to replace those lost from the skin surface and for wound healing
What are melanocytes derived from
Neural crest
What does melanin determine
Skin colour
What is melanin synthesis promoted by
Oestrogen, pituitary hormones
What is found in the Stratum Spinosum layer
Maturing keratinocytes and langerhans cells
What is found in the Stratum Granulosum later
Keratinocytes that become increasingly fun of keratins and other proteins as they undergo programmed cell death
Describe the Stratum Lucidum later
It is a thin layer of dead skin cells
Composed of 3-5 layers of dead flattened keratinocytes
What is found in the Stratum Corneum later
Dead cells, keratin and waterproofing substances
Describe the dermis layer
It is less cellular than the epidermis
What does the dermis play an important role in
Important in
- Support
- Strength
- Elasticity
- Vascular supply
- Nerves
- Sweat glands
- Sebaceous glands
- Hair
Name some normal skin lesions
- Freckles
2. Moles
What is another term for freckles
Ephelis
Describe freckles
Small flat brown marks arising on the face and other sun exposed sites
What is another term for moles
Melanotic macule or menaocytic naevus
What are moles
They are benign proliferating melanocytes
Describe how a mole may look
Can vary in tone from pink to black
The number of moles is determined by genetics and degree of sun exposure
Name some different types of naevi
- Junctional Naevi
- Compound naevus
- Intradermal naevus
Describe where junctional naevi
Early naevus cells form nests on the junction between the epidermis and the dermis
How do junctional naevi look
These moles are flat and colourful
Describe where compound naevi
Nest of naevus cells formed in the dermis
Describe where intradermal naevi
These are contained within the dermis only
How do intradermal naevi look
They are thickens and protrude from the skin surface
They may not be pigmented
How do we classify skin types
The Fitzpatrick scale
How do we use the Fitzpatrick scale to classify skin types
I- VI
Describe skin type I
Always burns
Never tans
Light, pale white
Describe skin type II
Usually burns
Sometimes tans
White, fair appearance
Describe skin type III
Sometimes mildly burns
Usually tans
Medium, white to love appearance
Describe skin type IV
Rarely burns
Always tans
Olive, moderate brown appearance
Describe skin type V
Very rarely burns
Tans with ease
Moderate constitutional pigmentation
Brown, dark brown appearance
Describe skin type VI
Never burns
Tans very easily
Marked constitutional pigmentation
Very dark brown, black in appearance