Skin biopractical thermoregulation

What is thermoregulation controlled by

• hypothalamus

Stages of thermoregulation

• (Thermo)sensors

• control centres

• effectors

What does the hypothalamus use to control temperature

• negative feedback loop (homeostasis)

What is allostasis and how does it work

• stability through change (flexible set-points)

• anitcipatory (brain/ hormones adapt before stress hits)

Is allostasis harmful

• short-term = protective

• long-term = harmful

What happens if there is chronic activation of allostasis

allostatic load (wear and tear)

E.g. of effectors in thermoregulation

• sweat glands (sweat evaporates)

• blood vessels (vasoconstriction/ dilation)

• muscles (shivering)

What are goosebumps activated by and how

• cold and stress

• sympathetic nervous system

• arrector pilli muscles contract and hair follicles contract

What is psoriasis

• chronic inflammation, thickened plaques, barrier disruption

• increased blood flow

• skin feels warmer

What does allostatic load do with psoriasis

• immune system always activated

• baseline temp regulation shifts

What does thickened plaques in psoriasis cause

decreased sweating efficiency

What does the barrier disruption cause in psoriasis

increased water loss and heat loss risk

What happens (thermoregulation) in burns

• heat and water

• barrier completely lost - rapid heat and water loss

What is acne vulgaris

• overproduction of sebum, follicular plugging, bacterial overgrowth (cutibacterium acnes)

What is eczema

• water and heat

• barrier breakdown —> increased transepidermal water and heat loss

Purpose of goosebumps and how do they do this

• hair stands upright and traps thin layer of air (reduces heat loss)

What happens (thermoregulation) in burns

• cooling ability

• damaged sweat glands - decreased cooling ability

What happens (thermoregulation) in burns

• local temp

• vasodilation around wound - increase local temp

What happens (thermoregulation) in burns

• severe burns

• systemic thermoregulation failure

What does inflammation in acne vulgaris cause

• localised heat and redness

Is systemic thermoregulation affected in acne vulgaris

• systemic thermoregulation not affected but inflamed follicles have abnormal local microenvironments

Impact of eczema inflamed skin

• increased local blood flow and warmth

What causes persistent inflammation in acne vulgatis

• chronic stress/ allostatic load

What does scratching eczema cause

• microdamage worsens heat regulation