Week 6: Integumentary Flashcards
What are the 3 layer of the skin?
Epidermis, dermis, hypodermis
What are the 6 main functions of the skin?
- protection
- regulation of body temp
- formation of vitamin D
- cutaneous sensation
- absorption
- excretion
What does skin protect against?
- temp and humidity
- disease
- UV rays
- pressure, blows and abrasion
- chemical substances
What is the optimal body temp for enzymes?
Constant around 36.8°C
When metabolic rate increases wha happens to body temp?
Increases
Where does most heat loss occur through?
The skin
What are mechanisms of heat loss?
- radiation
- evaporation
- conduction
- convection
Define radiation
Heat away from the body
Define evaporation
When the body is called, body heat converts the water in sweat to water vapour
Define conduction
When clothes and other objects in direct contact with the skin take up heat
Define convection
Air passing over the boy, raising heat off the surface of the skin, this also has a cooling effect
What are processes done by the body when its too hot?
- vasodilation
- sweating
- pilorelaxation
- stretching out
What are processes done by the body when its too cold?
- vasoconstriction
- shivering
- piloerection
- curling up
Define vasodilation
Arterioles dilate so more blood enters skin capillaries so heat is lost
Define sweating
Sudorific glands secrete sweat which removes heat when water changes state
Define pilorelaxation
Hairs flattening
Define stretching out
Opening up the body to a larger surface area
Define vasoconstriction
Arterioles get smaller to reduce blood going to the skin, keeping the core warm
Define shivering
Rapid contraction and relaxing of skeletal muscles, producing heat via respiration
Define curling up
Making yourself smaller so smaller surface area
Define piloerection
Hairs standing up on the skin
What does cutaneous sensation lead to?
Being sensitive to
- temp
- pain
- pressure
- touch
What is cutaneous sensation felt by?
Sensory receptors
What is skin absorption?
The route by which substances can enter the body through the skin
What factors does absorption through the skin depend on?
- concentration
- duration of contact
- solubility of medication
- physical condition of the skin
Define excretion
The process of removing wastes and excess water from the body
What are the types of wounds?
- abrasion
- laceration
- avulsion
- incision
- puncture
- amputation
What is primary wound healing ?
Healing that involves minimal destruction of the tissue e.g. surgical incision
What is inflammation healing?
In the first few hours, the cut surface becomes inflamed, the hap is filled with fibrin and cell debris
What is healing via phagocytes?
Removing the clots and cell debris which stimulates fibroblast activity
What is secondary healing?
Extensive tissue destruction, where edges of sounds cannot be brought together, such as pressure sores/ulcers, healing time relates to the size of the wound and removal of the cause
What are the two types of sweat glands?
- eccrine
- aporcine
what is the most important function of sweat glands?
The regulation of temperature
What are some effects of aging on the skin?
- basal layer is less active
- epidermis thins
- fewer elastic collagen fibres
- sweat glands and temperature regulation less efficient
- loss of pigment melanin causing grey hairs
What drains the dermis?
A network of lymph vessels
