negative feedback control | a regulatory mechanism in which a 'stimulus' causes an opposite 'output' in order to maintain an ideal level of whatever is being regulated |
negative feedback control | a regulatory mechanism in which a 'stimulus' causes an opposite 'output' in order to maintain an ideal level of whatever is being regulated |
What is homeostasis? | the maintenance of stable internal conditions in living organisms |
4 examples of homeostasis | blood water concentration, blood sugar, temperature, blood pH |
normal human body temperature | 37 degrees celcius |
Where do we get the energy to stay warm? | food (aerobic respiration) |
What is in your body core? | brain, heart, lungs, digestive system, kidneys |
What is in your body shell? | skin, fat, muscle, limbs |
Why is arm temperature greater than hand temperature? | it's closer to the body core |
Why does body temperature need to be kept at 37 degrees celcius? | vital organs might not function otherwise - you could die |
What does a thermoreceptor moniter? | blood temperature |
What part of the brain contains thermoreceptors? | hypothalamus |
Where else other than the brain can you find thermoreceptors? | the skin |
What 3 effectors are used in the human response to overheating? | sweat glands, small arteries in skin, hair erector muscles |
sweat glands in the human response to overheating | the water in sweat is evaporated using heat energy on the skin, this has a cooling effect |
small arteries in skin in the human response to overheating | they dilate to carry blood very close to skin surface so it appears red, heat is lost by radiating energy to the surroundings, this is called vasodilation |
hair erector muscles in the human response to overheating | they relax so hairs lie flat on the skin and they do not keep a layer of insulating air |
What are the effectors involved in the human response to cooling? | sweat glands, small arteries in skin, hair erector muscles, skeletal muscles |
sweat glands in the human response to cooling | no sweat is produced so heat is conserved |
small arteries in skin in the human response to cooling | vasoconstriction - they constrict to keep blood away from the skin so it appears blue, little heat is lost by radiating heat to the surroundings |
hair erector muscles in the human response to cooling | contract so hairs stand on end and trap a layer of insulating air |
skeletal muscles in the human response to cooling | contract and relax to cause shivering which generates heat to warm the body |
negative feedback control | a regulatory mechanism in which a 'stimulus' causes an opposite 'output' in order to maintain an ideal level of whatever is being regulated |
What is thermoregulation? | the maintenance of a set temperature in organisms |