Integumentary System I – Structure & Function Flashcards
What is the Epidermis?
Superficial, thinner
layer comprised of epithelial tissue
What is the dermis?
Deeper layer comprised
of connective tissue
What are the components of the integumentary system?
Skin, hair & sensory receptors
Nails
Oil and Sweat glands
What is the largest organ in the body?
Skin
On average, adults have how many metres of skin?
2 metres
Skin contributes approximately how many kilos of total body weight?
Approx 5kg
What is the average thickness of skin on a human body?
1-2mm
What are epidermal ridges also known as?
Fingerprint, handprint, footprint
What are striae more commonly known as?
Stretch marks
Name the 3 skin pigmentations?
Melanin, Haemoglobin and Carotene
What are the 2 types of melanin?
Pheomelanin (Yellow to Red)
Eumelanin (Brown to Black)
Melanin absorbs UV radiation. True or False?
True
What are freckles?
Accumulation of melanin patches, often due to uv radiation
What are carotene rich foods?
Egg Yolks and Carrots
What are functions of hair?
UV Protection
Thermoregulation
Light touch sensation
What is the scientific name for the sweat glands?
Sudoriferous glands
What is the scientific word for ear wax?
Cerumen
What is the purpose of earwax?
Impedes entry of foreign bodies and waterproofing of the ear canal
- Name the 3 main components of a nail
Nail body
Free Edge
Nail root
What are cells that produce collagen and elastin?
Fibroblasts
What does reduced melanocytes cause?
Grey hair
Why do we get hair loss?
Follicles stop producing hair
What is the name for a normal mole?
Nevus
What are some causes of skin cancer?
Skin type - Individuals with lighter skin who never tan and always burn at highest risk
Sun Exposure - Increased sun exposure increases cancer risk | UV exposure
Family History -Family history of cancer increases risk
Age - Aged individuals at higher risk due to longer total exposure to U
Immunology status - Immunosuppressed (weakened immune system) individuals at greater risk
What are three common types of skin cancer?
Basal Cell Carcinomas (75% of skin cancers)
Squamous cell Carcinomas (20% of skin cancers)
Malignant Melanoma (2% of skin cancers)
If a malignant melanoma goes undiagnosed, it can kill a person, how quickly?
Within months
In a malignant melanoma, what happens in stage 3?
Disease spread to lymph nodes or nearby skin
In a malignant melanoma, what happens in stage 1?
Localised to epidermis under 1mm thick
In a malignant melanoma, what happens in stage 2?
Localised to epidermis, 1-4 mm thick
In a malignant melanoma, what happens in stage 4?
Metastasis to other internal organs
Lymph node involvement
Ageing causes wrinkling through loss of what?
integumentary cells & glands
Malignant melanomas can be identified using what acronym?
A B C D
What area of skin has a thickness of around 4mm?
Heel
What area of skin as a thickness of around 0.5mm?
Eyelid
How does the skin synthesise vitamin D?
UV radiation synthesises Vit D via calcitriol (aids calcium absorption)
Explain the skin’s function as a blood reservoir
Dermis has extensive network of blood vessels | Carry 8-10% of blood at rest
Explain the skin’s ability to excrete and absorb
Excretion of sweat | Absorption of lipid-soluble materials (e.g. Vitamins A, D, E, K | Cortisone)
What is the hypodermis?
Subcutaneous layer consisting of
areolar & adipose tissue
What are Langerhans cells?
One of the cells found in the epidermis. Participate in immune responses against microbes that invade the skin
What are Keratinocytes?
One of the cells found in the epidermis. Arranged in 4-5 layers | Produce keratin | Protects skin from external environment
What are Melanocytes?
One of the cells found in the epidermis. Produces melanin | Transfer melanin to keratinocytes | Contributes to skin pigment |
Absorbs UV light
What are Merkel cells?
One of the cells found in the epidermis. In direct contact with sensory neurons via a Merkel disc | Detect touch sensations
How many layers of thin skin are there?
4
Which layer of skin is categorised by - 25 – 30 layers of dead keratinocytes which are shed & replaced by deeper cells
Stratum Corneum
Which layer of skin is categorised by - 3-5 layers of flattened keratinocytes undergoing apoptosis | Lipid
secretions provide waterproofing
Stratum Granulosum
Which layer of skin is categorised by - 8-10 layers of keratinocytes fitting closely together that provide
strength and flexibility to skin
Spinous Spinosum
Which layer of skin is described as a Single layer that contains stem cells that undergo cell division to continually
produce keratinocytes
Stratum Basale
What is the extra 5th layer of skin called that is located between the Stratum granulosum & thickened stratum corneum?
Stratum lucidum
What is apoptosis?
Cell death
How long does Keratinisation take?
Approximately 4 weeks
What is Keratinisation?
As cells move closer to the
surface of the skin, they accumulate more keratin
What are Meissner corpuscles?
touch sensitive nerves
Why do our cheeks go red?
Skin appears pink to red depending on oxygen content of blood moving through
capillaries of the dermis due to haemoglobin (oxygen carrying pigment in red blood cells)
What colour can your skin go if you have too much carotene?
Orange
