Homeostasis

This course has the information needed for the Term 1 science exam.  Features: the central nervous system, the peripheral nervous system, neurons, neurotransmission, the endocrine system, the circulatory system, the respiratory system, the digestive system, metabolism, blood glucose regulation, body temperature regulation, disease, immunity, bacteria, pathogens, viruses, fungi, parasites, transmission and prevention of disease, the three lines of defense and vaccination.     The key definitions will be bolded and highlighted in red. 

What is homeostasis? Homeostasis is the maintenance of a relatively stable internal environment.   Organisms are able to detect changes that could disrupt their stable internal environment. The change that the animal detects is called a stimulus The part of the organism that detects the change is called the receptor Information about the stimulus can be processed by a control centre (brain), which coordinates a response The part of the organism which causes the response is called the effector   Stimulus-Response Model    Stimulus  ->  Receptor  ->  Control Center  ->  Effector  ->  Response   example:  Cold Temperatue -> Skin  ->  Brain->  Muscles  -> Shivering  example:  Hot Temperature   ->  Skin  ->  Brain  ->  Sweat Glands  ->  Sweating     Positive and Negative Feedback Loops   A negative feedback loop produces a response that is opposite to the stimulus. A positive feedback loop produces a response that is the same as the stimulus.              

The Nervous System is a communication system that controls all parts of your body. The human nervous system has two main parts:   Central nervous system (CNS)  Brain & Spinal Cord   Peripheral nervous system (PNS)  All the rest of the nerves.