Skin Flashcards
What are the three primary layers of skin?
Epidermis, dermis and hypodermis.
Skin is what percent of our body weight?
16%
What are the Functions of skin and accessory structures?
Protect Excrete Maintain body temp Produce melanin Produce keratin Synthesise vita D Store lipids Detect touch
What layers of the skin are part of the cutaneous membrane?
Epidermis and dermis
What is the subcutaneous layer?
Hypodermis
What tissue type dominates in epidermis?
Epithelial tissue
What are the different types of epithelia?
Simple or stratified, squamous, cuboidal or columnar.
The epidermis is made out of what type of epithelia?
Stratified squamous epithelium.
What are the layers of epidermis from top to bottom.
Stratum corneum
Stratum granulosum
Stratum spinosum
Stratum basale
What is the function of desmosomes in the epidermis?
Anchors neighbouring cells.
What is the function of hemidesmosomes in the epidermis?
Anchors stratum basale to the dermis
What layer of the epidermis can be completely removed?
Stratum corneum (horny layer)
What layer is found only in thick skin?
Stratum lucidum
What is the difference between thick and thin skin?
Thick skin has an extra epidermal layer
What are the two layers of the dermis?
Papillary layer and the reticular layer.
Describe the papillary layer?
Consists of highly vascularised tissue.
Describe the reticular layer?
Mesh like structure of collagen and elastin fibres (for strength)
Both the papillary and reticular layers of the dermis contain what?
Blood vessels, lymphatics, sensory nerve fibres and accessory structures.
What are the types of plexuses of the dermis?
Cutaneous and subpapillary.
What layer of the skin is not considered part of the skin?
Hypodermis
The hypodermis is dominated by what?
Adipocytes that produce subcutaneous fat.
What is the common site of injections?
Subcutaneous layer
What is the healing time for a first degree burn?
3-10 days
What is the healing time for a normal second degree burn?
1-2 weeks
What is the healing time for a deep second degree burn?
1 month
Third degrees burns are known as?
Full thickness burns
Second degree burns affect what layers of skin?
Epidermis and dermis.
First degree burns effect what layer of skin?
Outer layer of the epidermis.
What are the four accessory structures?
Hair
Sweat glands
Receptors
Nails
The contraction of what muscle caused goosebumps?
Arrector pili muscle
Melanocytes are found where?
Stratum basale
Moles are caused due to an over preliferation of what?
Sun exposure
What are the two types of sweat glands?
Eccrine and apocrine
Vitamin D is essential for what?
Normal calcium metabolism and strong bones.
A calcium deficiency can cause what?
Rickets and also affects mood.
Sebaceous glands produce what?
Sebum
Where are the apocrine glands found?
Armpit, groin and around the nipples.
What makes a freckle?
Melanocytes overproducing melanosomes
What makes a mole?
Cluster of melanocytes
Who are most susceptible to vitamin d deficiency?
Highly pigmented people
What are the 5 types of skin receptors?
Free nerve endings Tactile discs Tactile corpuscles Lamellar corpuscles Bulbous corpuscles
Free nerve ending respond mainly to what?
Temperature and pain, some movement and pressure.
Tactile discs respond mainly to what?
Texture, shape and edges. And fine touch and light pressure.
Tactile corpuscles respond mainly to what?
Delicate touch. Light pressure and low frequency vibration.
Lamellar corpuscles respond mainly to what?
Deep pressure and vibration.
Bulbous corpuscles respond mainly to what?
Sustained deep pressure, stretching and distortion of the skin.
Skin blood flow is important in what role?
Thermoregulation and blood pressure control.
What is our normal range for body temp?
36.5-37.5 core body temp.
What are the primary mechanisms for heat transfer?
Radiation
Evaporation
Convection
Conduction
What is the preoptic area?
Area in the hypothalamus that contains heat and cold sensitive neurons called central thermoreceptors.
If blood temp increase what are the 3 main things that happen?
Vasodilation
Sweating
Increased respiratory rate
+ behavioural changes
What are the three heat generating mechanisms?
Shivering, non-shivering thermogenesis and increased thyroxine.
Describe an arrector pili muscle?
Smooth muscle innervated by the SNS
What is the role of arrector pili muscles?
Contraction pulls hair upright and dimples skin causing goosebumps.
What are three potential complication caused by severe burns?
Dehydration and hypovolemic shock.
Infection/sepsis
Hypothermia
