Thermoregulation

• Ectotherms include most fish, amphibians, reptiles, and many insects.
• Convection is the transfer of heat through the movement of fluids, such as the circulation of warm air rising and cool air sinking.
• There are two types of receptors involved in thermoregulation: warm-sensitive (heat) receptors and cold-sensitive (cold) receptors.
• Thermoregulation is the maintaining of constant body temparature by a negative control feedback system
• The production of heat in the body is called Thermogenesis
• The loss of heat in the body is called Thermolysis
• Factors involved in thermoregulation: skin, sweating, shivering and insulation
• Ectothermic: to use energy from the environment to maintain body temparature
• Endothermic: to use internal metabolic energy to maintain body temparature.
• Skin layer makeup: epidermis, dermis, hypodermis
• sebaceous glands - let out antiseptic sebum, keep skin supple, prevent dehydration

  1. basal layer-contains melanin pigment to protect against UV rays
  2. Blood vessels, arteries and capillaries- carry O2 to sktthehe in, remove waste from skin, promote temperature regulation through dilation and contraction
  3. Cornified Layer- contains dead cells , prevents entry of bacteria, protects against injuries, protects against desiccation
  4. Sweat glands - causes cooling
  5. Sensory neurons - sensitive to environmental conditions and changes
• name the function of the basal layer

  contains melanin pigment to protect against UV rays
• what does the hypodermis contain?

  Loose connective tissue and fat cells
• Vasodilation: circular muscles of the dermal arteriole are not stimulated by nerve impulse, so they relax and the lumen widens.
• Vasodilation allows warm blood to flow to the capillaries in the upper dermis of the skin
• heat can be lost through conduction and convection
• conduction: heat lost from warmer object to cooler object when they touch
• vasoconstriction: the constriction of blood vessels, which increases blood pressure. signals are sent to the dermal arterioles, causing the circular muscles to contract, narrowing the lumen.