Lecture 2 Flashcards
Anatomy of the skin - II
What are the accessory structures?
Hair, Sweat glands, Nails, Receptors
Where is hair found?
All over the body except on thick skin (palms, soles of feet and lips)
What is hair?
Dead, keratinised cells
Where does hair originate from?
Inside the hair follicle
What is the muscle responsible for goosebumps?
Arrector pili muscle
What does the arrector pili muscle do?
Contracts to form goosebumps which creates an airlock and improves insulation
What is the root hair plexus?
The collection of sensory nerves at the base of each hair follicle which heightens sensation
What is a sebaceous gland?
A gland within the hair follicle that produces sebum
What does sebum do?
Nourishes hair shaft and naturally moisturises the skin. Is an oil and therefore has water repealing properties
What is acne?
A blocked hair follicle with an infection from over production of sebum
What is lanolin?
Sheep sebum
What are the two types of sweat gland?
Eccrine and Apocrine
What is an eccrine sweat gland?
Found all over the body and produces a watery secretion. They are important for thermoregulation and excretion as well as limited antibacterial properties
What is an apocrine sweat gland?
Found in specific areas (armpit, groin, nipples) and produce an oily and sometimes odours secretion into the base of the hair follicle. These can be influenced by hormones
What are the accessory structure receptors in the skin?
Tactile, lamellar, bulbous
What is the purpose of nails?
To protect the fingers and toes, enhance sensation and limit the deformation of sensory receptors to stop damage occurring to the areas while activating a receptor
What is aging?
The thinning of the epidermis and dermis resulting in reduced collagen, slower skin repair, less sebum and sweat as well as less pigmentation
How does smoking cause premature aging?
The tobacco contains agents that damage the collagen and elastin in the skin. This is linked to poor wound healing, acne, skin and oral cancers
How does vaping cause premature aging?
The nicotine reduces blood circulation in the dermis
What is contact dermatitis caused by?
The metal coating on vapes which causes inflammation of the skin around the mouth
What are melanocytes?
The cell in which melanin is produced. They are fixed within the stratum basale
What are melanosomes?
The vesicles that carries the melanin to the epidermal cells
What is melanin?
A pigment that absorbs UV light and protects the cells from UV damage
What is a freckle?
The over-production of melanosomes by melanocytes triggered by sun exposure
What is a mole?
A cluster of melanocytes of which the over-proliferation can be cause by sun exposure
Why is vitamin D essential?
For normal calcium metabolism and strong bones
What can vitamin D deficiencies cause?
Rickets
What are rickets?
The deformation of growing bones in children from the softening and weakening of bones due to lack of calcium from a prolonged vitamin D deficiency
How is vitamin D synthesised?
UV exposure on the skin
What are the two types of skin cancer?
Basal cell carcinoma and malignant melanoma
What is basal cell carcinoma?
A common but relatively benign form of skin cancer that originates in the stratum basale of the epidermis. Metastasis throughout the body is rare.
What is malignant melanoma?
A rare and deadly form of skin cancer that originates in melanocytes. It is highly metastatic, depending on the depth of the mole
What is a tattoo?
An artificial pigmentation deposited within the dermal layer of the skin that is captured but not broken down by immune cells and scar tissue
What is a ‘lena’?
The tattoo pigmentation being present within the lymph nodes which appears the same as melanoma
What are the different types of tattoo?
Trauma, decorative, cosmetic and cultural
