Homeostasis SAQs.docx

Homeostasis SAQs - What is homeostasis?  A. the ability of an organism to maintain a constant internal environment - Why is homeostasis important to the human body?  1. it is vital that organisms can maintain a constant internal environment to allow for regular metabolism to occur  -...

Homeostasis SAQs - What is homeostasis?  A. the ability of an organism to maintain a constant internal environment - Why is homeostasis important to the human body?  1. it is vital that organisms can maintain a constant internal environment to allow for regular metabolism to occur  - What is an endotherm? a. Endotherms are animals that can produce internal heat from metabolism. - What is an ectotherm? a. Ectotherms are animals that rely on their external environment to control their body temperature. - Where in the skin is keratin made?  1. The granular layer  - What is the function of melanin?  1. Melanin gives colour to the skin, hair and iris, melanin also protects the skin against UV radiation.  - What is vasodilation?  1. increased blood flow resulting in increased heat loss - How does the skin retain heat in cold conditions?  1. piloerection (hairs stand up and trap a layer of air) and vasoconstriction (decreased blood flow and reduced heat loss) - List 2 functions of the skin  1. Protection against bacteria and viruses/ produces vitamin D/ acts as a sense organ/ temperature regulation