Lecture 2: Anatomy of the skin, Part 2 Flashcards
What are example accessory structures to the skin?
4
- Hair
- Sweat glands
- Receptors
- Nails
Where is hair located?
All over the body
Where is hair prominent?
On the head
What does hair consist of?
4
- Hair shaft
- Hair follicle
- Arrector pili muscle
- Sebaceous gland
Where does hair grow from?
The follicle
What does the Arrector pili muscle connect to?
The follicle
What is the Arrector pili muscles an example of?
Muscle tissue
What does the sebaceous gland do?
Produces sebum
What is sebum?
2
- A natural moisturiser
- Water repellent
What is Acne?
A blockage of hair follicles + infection
What is a result of increased sebum?
Increased risk of acne
Where is sebum production highest?
3
- Head
- Face
- Shoulders
What are 2 types of sweat glands?
- Eccrine sweat glands
- Apocrine sweat glands
Where are Eccrine sweat glands found?
All over the body
What is the function of Eccrine sweat glands?
Thermoregulation
Where are Apocrine sweat glands found?
Deeper in the skin
What is the function of Apocrine sweat glands?
Release oily substance into the base of the hair follicle
What are pheromones secreted by?
Apocrine glands
What are three types of skin receptors?
- Tactile
- Lamellar
- Bulbous
How do receptors interpret sensation?
Deformation - Change in shape
What are functions of nails?
2
- Protect fingertips
- Enhance sensation
What is melanin?
It is a pigment
What does the pigment melanin do?
Absorbs UV light, protecting cells from UV damage
Where is melanin produced?
Melanocytes
How is melanin transferred to epidermal cells?
Melanosomes
What are melanosomes?
Vesicles containing Melanin
What is a mole?
A cluster of melanocytes
What can cause over proliferation of melanocytes?
Sun exposure
What is a freckle?
Melanocytes overproducing melanosomes
What causes the overproduction of melanosomes?
Sun exposure
Where are Melanocytes found?
Only in the Stratum basale
Where are Melanosomes found?
Throughout the Epidermis
What happens to the density of Melanocytes throughout the body?
It varies throughout the body
Does the density of melanocytes vary between races?
No
Why is human skin pigmentation so variable?
It matches UV exposure to that of indigenous populations
What is vitamin D required for?
2
- Normal calcium metabolism
- strong bones
What can vitamin D deficiency result in?
2
- Rickets
- Mood swings
What is required for vitamin D synthesis?
UV exposure
What is the likely reason for less skin pigmentation in people at higher latitudes?
Less UV exposure
Are highly pigmented people more or less susceptible to Vitamin D deficiency?
More susceptible
Where are highly pigmented people located when more susceptible to vitamin D deficiency?
Extreme latitiudes
When do reported incidents of rickets become greatest?
During winter and spring
What is particular about NZ UV exposure?
It is intense
What are 2 types of skin cancer?
- Basal cell carcinoma
- Malignant melanoma
Where does Basel cell carcinoma originate?
Stratum basale
What are features of Basal cell carcinoma?
2
- Common but relatively benign
- Metastasis is rare
Where does Malignant melanoma originate?
In melanocytes
What are features of Malignant melanoma?
3
- Rare but deadly if not treated
- Highly metastatic
- Mortality rate due to tumour, dependant upon the tumour
What is Metastasis?
tumour breaking off and growing into new tumours in new places
What does the thickness of a melanoma correlate with?
Mortality rate
What does a thicker melanoma mean?
2
- The deeper into the dermis it can get
- The more likely it is to get into the circulatory/lymphatic system
What is a tattoo?
Artificial pigmentation
What layer is artificial pigmentation stored in for tattoos?
The Dermal layer
What type of cells/tissue are tattoos stored in?
Immune cells/Scar tissue
What are examples of different types of tattoos?
2
- Trauma
- Decorative/Cosmetic
What is a trauma tattoo?
When foreign bodies become forcibly embedded in the skin
What does the Arrector pili muscle aid in?
The insulatory effect
