the skin and temperature Flashcards
what is the integumentary system
skin/nails/hair
what is the biggest organ in the body
the skin
what is the technical name for the skin
the cutaneous membrane
what are the accessory structure to the cutaneous membrane
hair
nails
sweat and oil glands
what are the 2 main layers of the skin
epidermis
dermis
what is below the dermis called?
what kind of cells are they?
what is the layer called?
- hypodermis
- adipocyte cells
- subcutaneous layer
epidermis;
- what is its structure
thinnest layer of skin
outer layer of skin
non-vascularised (no capillaries)
dermis;
- what is its structure
tough, strong and fibrous connective tissue to help maintain structure
it is also vascularised - a good blood supply lots of veins/arteries/capillaries
what structures does the dermis contain
- blood supply (veins & arteries)
- nerves
- hair follicles
- sweat glands
- sebaceous gland
differences between the epidermis and dermis
epidermis is non-vascularised but the dermis is vascularised
epidermis is thin but the dermis is tough, fibrous and strong
the dermis have nerves within it what does this mean
it is where you can feel sensations such as heat/touch/pain/pressure
what does the dermis contain to maintain structure
fibrous connective tissue and collagen
what type of tissue is the hypodermis
subcutaneous tissue - not technically skin
what is the hypodermis role
protection structure stores adipose tissue (fat) provides insulation calories reservoir
what are the 5 layers of the epidermis skin tissues
- stratum corneum
- stratum lucidum
- stratum granulosum
- stratum spinosum
- stratum basale
explain the stratum basale
- deepest layer next to the dermis
- mitosis creates new daughter epidermal cells
- new cells are pushed upwards towards the stratum spinosum
explain the stratum spinosum
- tightly compacted and connected - adjacent to reduce tension
- cells become flattened as they get pushed upwards - change from their rounded shape
- cells start to die as they get pushed towards stratum granulosum
explain the stratum granulosum
- contain granules
- release lipids (fats)
- make skin waterproof
explain the stratum lucidum
- contain large amounts of keratin (fibrous fibres)
- only pressent in hairless ares ie palm of hand or soles of feet
explain the stratum lucidum
- contain large amounts of keratin (fibrous fibers)
- only present in hairless ares ie palm of hand or soles of feet
what are the functions of the skin
- protection
- control body temperature
- metabloic function
- cutaneous sensation (ie warmth or cold)
- blood resivour
- excretion of substances
- sensations (sensoru neurons)
- preventative
what are the functions of the skin
- protection
- control body temperature
- metabolic function
- cutaneous sensation (ie warmth or cold)
- blood resivoir
- excretion of substances
- sensations (sensory neurons)
- preventative
a baby born after 38weeks -
1. how thick is their dermis
2. when will their sweat glands mature
3.
- 2-4mm thick
2. after 1 week
what is the brown adipose tissue
it is a thick later of brown fat used for energy and insulation in newborn babies
- they use it for extra energy if they have used up their glucose and glycogen stored energy
- it also insulates the as babies cant shiver so the fat insulates them
where is the brown adipose tissue stored
Subcutaneous Layer lipid deposits
what is the name for the slightly yellow layer ontop of the skin of a newborn baby
vernix caseosa
what is the name for the slightly yellow layer on top of the skin of a newborn baby
vernix caseosa
what does the vernix caseosa do
protects, moisturizes and facilitates colonisation
why shouldn’t you bathe babies immediately after birth
because it’ll break the vernix caseosa
preterm babies.
- what is their dermis like
- what is their skin like
- how long does it take for their sweat glands to mature
- very thin
- transparent and gelatinous and not as fibrous as the layers of skin arent very well connected so skin looks red
- 21-33 days
what are the cells that affect skin colour
- melanin (influencing pigmentation in skin)
- carotene (yellowing of the skin)
- haemoglobin (levels of haemoglobin and oxygen levels) ie poorly people will become very pale as they are deprived of blood flow as the blood is needed for vital organs
what do sebaceous glands do?
- produce oil (sebum)
- kills bacteria
- lubricant for skin
- prevents brittle hair
what are the two types of sweat glands
eccrine - open vi duct to pore on skin surface
apocrine - ducts empty into hair follicles
functions of sweat glands/what do they do?
produce sweat
- excretes waste products from the body
- is used to cool the body down
- evaporation occurs when sweat is evaporated from the body
how does sweat get an odur
the acidic nature of sweat inhibits bacteria growth - odour is associated with the present and growing bacteria
what does sweat contain
mostly water
salts and vit c
metabolic waste
fatty acids and proteins (apocrine sweat glands only)
nails - what are they made of
heavily keratinized (tough fibrous protein produced by keratinocytes)
where do nails grow from
stratum basal extends beneath the nail bed
what are some homeostatic imbalances
- extreme stretching
- blistering
- age
- oxygenation
- sebaceous blockages
explain the stages of wound healing
1. bleeding (creating a blood clot) 2. inflammatory (fibroblast macrophage scab) 3. proliferative (fibroblast proliferating / subcutaneous fat) 4. remodeling (freshly healed epidermis / healed dermis)
stages of pressure sores
- firstly, pressure sores affect the upper epidermis
- then moved through the epidermis layers breaking into the dermis
- going deeper into the dermis breaking intothe subcutaneous fat
- breaking through the soft tissue near the bone
how many grades of pressure sores are there
4
explain a grade 1 pressure sore
- non-blanchable erythema (redness) of intact skin
- discoloration of the skin
- hardness or oedema of the skin
only affecting the top layer of epidermis
explain grade 2 pressure sores
- partial thickness of epidermis and dermis is lost
- ulcer is clinically seen as a abrasion or blister
explain grade 3 pressure sores
- full thickness skin loss
- damage to subcutaneous tissue/hypodermis
- extend to fascia but not through
explain grade 4 pressure sores
- damage to tissue, muscle and bine
- full thickness skin loss
what are the 4 mechanisms of heat loss in humans
- radiation (when head radiates off you)
- convection (when something blows past you taking heat with it ie; air conditioning)
- conduction ( when you are pressed against a cold surface - heat is taken from you to the cold surface)
- evaporation (when you get wet and the water evaporates away from you)
what is the blood clotting process
- damaged blood vessels trigger the release of a chemical vasospasm
- forming a platelet plug
- prothrombin is turned into thrombin
- activating solutable fibrinogen to turn into insoluable fibrin
what is platelet plug
where vasoconstriction limits blood flow where platelets form a sticky plug
how does thermoregulation increase body temperature
- vasoconstriction with the blood vessels (to decrease extra heat loss)
- shiver the body’s skeletal muscles contracts rapidly - this generates heat
- arrector pili muscles makes the hair on your skin stand up which will trap air next to the skin insulting the body reducing heat loss
how does thermoregulation decrease the body’s temperature
- vasodilation with the blood vessels (to increase blood flow and increase heat loss)
- sweat (the sweat glands will increase sweating to increase evaporation
other ways the body looses heat is: radiation and convection
