stimulus response Homeostasis刺激稳态幻灯片.pptVIP

Stimulus/Response Internal Stimulus A stimulus that comes from inside your body. EX. hunger pains, emotions, and a full bladder. External Stimulus Any stimulus from outside the body. Ex. flashing lights, scary or sad events. Response A reaction to a stimulus. When you are hungry you eat, when you are sad you cry, when you are scared you run… Internal Stimuli Responses External Stimuli Responses #22 Write. Looks like Joe is prepared to handle some stimuli… And That’s… Homeostasis A state of balance in the body Definition of Homeostasis homeo = same; stasis = standing Homeostasis is the term we use to describe the constant state of the internal environment. Homeostasis is a state of balance in the body. The processes and activities that help to maintain homeostasis are referred to as homeostatic mechanisms. Introduction You are exposed to ever changing environmental conditions. For example, you may walk out of an air conditioned room into the hot summer sun. However the cells in your body work best when their surroundings are kept constant. Your body has many mechanisms that keep the cells surroundings constant even though your external environment is changing. This is homeostasis. Homeostasis is very important because when it fails you become ill and may die.?? Maintaining Homeostasis Chemistry is the reason why we must maintain homeostasis.  Biochemical processes (the chemical reactions) that occur within us) are vital to life and occur efficiently only within a limited temperature range and at a specific pH. Internal Communication The body must have good internal communication, using the endocrine and nervous systems, to maintain homeostasis. Feedback inhibition limits the operation of a system or causes it to shut down when it senses too much of a certain product (such as water, glucose, salt, heat, CO2 etc.) It will cause the system to “turn back on” when there is too little of this product. A Temperature Control System To hel