Skin Flashcards
(32 cards)
What are the three layers of the skin?
Epidermis, which is the outer layer
Dermis middle in a layer
Subcutaneous layer fat cells
Which layer of skin are melanocytes found and what are their job?
Meleto sides produce melanin a pigment that protects cells from UV radiation reducing the risk of radiation induce mutations in the DNA of the skin cells
What is the stratum corneum and what is it to role?
The stratum corneum is the final layer of the epidermis which is made up of dead keratinise cells it functions as a major barrier for the loss of water due to it being rich in leopards which are impermeable to water although the layer is not waterproof?
Interstitial fluid gradually penetrate it and evaporates from the surface to the surrounding air
Describe the scalp epidermis as well as the relationship between hair molecules and the associated glands
The scalp has a thin epidermis and many sebaceous glands which secrete a waxy oily substance called sebum that helps lubricate and waterproof the skin
Describe the epidermis properties on the palms of the hands and souls of feet
Paws and hands is soles of feet have a non-hairy like skin and has a relatively thick epidermis due to wear and tear and numerous sensory receptors
What is dry skin? What are the reasons for it?
Dry skin refers to then not being enough water in the stratum corneum , the normal water content being 10 to 20% when it falls below 10% symptoms of dry skin may appear
Reasons for dry skin could be
aging – all the individual the epidermis begins to thin and lose ability to attend moisture
Sun over exposure
Exposure to cold weather
Inflammatory skin conditions such as dermatitis or eczema
People with dry skin may suffer a lot of flexibility, roughness and hyperkeratosis as well as inflammation and itching
Describe the process of cells reach reaching the stratum corneum
The inner most layer of epidural is made up of rapidly dividing cells attached to a basement to membrane which I found beneath sheets of epithelial cells throughout the body and in the skin or fastened to connective tissue by collagen molecules. In cases where the connections are absent, the epidermis becomes detach and blistering occurs.
Rapidly dividing cells move towards a skin surface as they begin to form a protein called keratin pushed up by the cells forming beneath them in 15 to 30 days the souls reach the outer layer stratum corneum
Describe and explain the components of the dermis
The dermis contains cells in a network made of two main types of protein
Collagen which provides strength and elastic which gives the skin flexibility
The dermis contains blood vessels and a number of other structures including sweat glands that’s a salt solution onto the skin surface, sebaceous glands which associated with how molecules and secrete sebum , a variety of sensory receptors
Explain hair follicles
You have forms at the route or hair shaft inside the follicles as the cells form all the cells are pushed out of the follicle cells dying become the hair we see
Have follicles go through two different periods, growth phases and a rough phase and then a growth phase again pushing the old hair up and out as it dies
Be a erector pilli is a muscle which contracts to pull the hair shaft erected in mammals with a lot of hair. This can be used to conserve heat by trapping insulated air however in humans it is just goosebumps.
Male patent boldness is caused by an increased sensitivity to male sex hormone androgens
Describe the two types of sweat glands and their functions
Appocrine can sweat glands are found adjacent to have molecules in hairy areas of the body such as the armpits in the groin and they produce sweat that contains organic chemicals including protein when these are broken down by bacteria on the skin they can produce an unpleasant odor
The rest of the skin has eccrine sweat glands which produce salty water and are cited between her follicles
Describe it explain sebaceous glands
Usually the cases near hair molecules and they produce a lipid containing sebum onto the surface of the skin which varies depend depending on the area of the body and its function is to keep the skin and water resistant and supple.
Acne is the bodies reaction to infection and inflammation of the sebaceous glands in males this is caused by testosterone near puberty and women is less understood and can lead to considerable psychological stress
Explain the subcutaneous layer
The subcutaneous layer is mainly made up of fatty tissue which acts question as well as an energy store. It also contains sensory nerve ending.
What are the functions of the skin?
Keratin protects underlining tissue from microbes, abrasion, heat and chemicals
Subum contains bacteriacidal chemicals that kill unwanted surface bacteria
Melanin helps protect the skin from UV
White blood cells (macrophage) in the dermis bacteria and viruses that get passed first line defences of epidermis
Acid pH of sweat also prevents growth of some microbes
Vitamin D is synthesised in the dermis of the skin due to a precursor that is activated by ultraviolet light without vitamin D the body would not be able to absorb calcium from food making the bones brittle so lack of sun indirectly causes rickets and osteoporosis
The dearest curry is 10% of the total blood flow of a resting adult
Skin is key and controlling body temperature
Explain the biochemical changes that take place when your body heat serve due to exercise and trying to cool self down
Evaporation takes place as sweat evaporates transferring energy from the body to the surroundings cooling down the body
Radiation – dilation takes place in blood vessel feeding the skin capillaries more blood flows through the capillaries close to the skin surface resulting in skin flushes as the energy against transferred to the surrounded by radiation
Conduction energy will be transferred from the body to any object that is cooler than the skin temperature
Convection energy from the body will be transferred to the closest layer of warming. The woman rises to be replaced with cooler and more energy will be transferred from the skin and cooling down each time.
Explain the biochemical process processes involve when your core body temperature starts to drop in the skin is trying to heat it up or prevent further cooling
Vasoconstriction blood vessel supplying the skin capillaries reduce blood flow on the skin so less energy is transferred to environment
Littleton, no sweat limiting loss of evaporation
Arrector pilli /goosebumps has a pulled upright as this muscle contracts insulating the layer of air to prevent energy transfer by conduction or convection
Shivering, involuntary contraction of skeletal muscles warms body by helping store body temp
In some animals and very young babies, special brown farts or metabolised just to transfer energy and warm the body
What is the ideal body temperature and why?
Internal body temperature is maintained around 37°C so enzymes that work metabolism can function optimum
The person may develop hypothermia if the temperature drops below 35° as thermogenesis is not sufficient to maintain metabolic reactions . In this case, shivering stops and normal mechanism to conserve the body will fail.
If the temperature is too high above 40 and I’m speaking to denature and can no longer colonise the reactions in the person develops hypothermia and may die in this case antipyretic medicines are important
What is the function of mechanoreceptors?
Responsive to mechanical stimuli such as stretching deforming and bending of cells e.g. touch and pressure
What is the role of photoreceptors?
Voice receptors respond to light cells in the epidermis produce melanin when exposed to ultraviolet radiation active pigmentation reflects intensity and duration time exposed to UV light
What is the Thermo receptor?
Respond to both heat and cold and protect you from picking up objects to hot or too cold helping the body thermal regulate by giving awareness of external temperature
What is the function of nociceptors?
Pain receptors respond to physical damage of tissues
Describe the key differences between epidermal wounds and deep wound healing
Deep wound healing is the epidermic only on a small cut and abrasions, healing occurs as the cells of the epidermal surrounding the wounds enlarge and cover to meet in the middle until they meet each other and stopped due to contact inhibition. And cells move across the hormone epidermal growth factor stimulates epidermal cells to divide and replace the ones that have been moved to seal the wound.
Deep wounds include four phases
Inflammatory phase blood clots form in the wound and loosely unit the two edges
Migratory phase blood clots become a scab and epithelial cells migrate below the scar to seal the wound damage blood vessels begin to regrow
Proliferative phase extensive growth of epithelial cells, collagen fibres deposited by fibroblasts
Mature and phase the scab “sloughs off” once the epidermis reaches a normal thickness
Describe dermatitis/eczema giving two common forms
Dermatitis is a term used to describe many inflammatory conditions of the skin and it’s also known as eczema. The condition can be acute or chronic and have different causes.
Allergic contact dermatitis results in exposure from a sensitising allergen and result in a definitive red slightly rough, itchy area with blisters that we went scratched
Urticaria or hives is a common form of dermatitis that is caused by allergens or by response to the bodies internal factors such as stress or infection and it produces a pale red raised itchy bumps on the skin
Describe it explain psoriasis
Psoriasis is a chronic autoimmune skin disorder that produces thickened inflamed areas of skin
The epidermal cells divide more quickly than normal on their journey to the stratum and shed prematurely leaving flaky silver scales
Although this is not understood well the condition can range from relatively mild to occasionally linked from stress to severe and constant
Explain acne
Acne is result of an overproduction of sebum from the sebaceous glands in teenage years, which mixes with dead skin and bacteria and can block hair follicle as well, sebaceous, apocrine and eccrine duct causing inflamed painful post filled areas which may even form cysts
Cystic acne can scar the epidermis permanently contrary to popular belief foods such as chocolate or fried foods do not worse an acne
