Receiving information from the environment to coordinate a response Pg

 Allows animals to detect and process signals to react to them  Stimulus: a signal that causes an animal to react Example: touch, sound, smells, tastes  Response: an animal’s reaction to a stimulus

 Neuron: nerve cell with a unique structure for receiving and passing on information.  Sensory Neuron: nerve cells that detect stimuli  Interneurons: nerve cells that pass information between neurons  Motor neurons: nerve cells that carry response information to muscles and other organs Types of Cells…

 “Nerve net”: Simplest nervous system are a netlike arrangement of neurons throughout the body  “Nerve cord”: Most complex have a nerve cord and a brain  Brain: organized grouping of neurons in the head of an animal  Receives info, interprets it and control’s an animal’s response

 A frog detects vibrations with its tympanic membrane  Platypus uses its bill to detect the movements of other animals  Most insects detect some colors and movement with their compound eyes  Shark uses cells in its nasal passages to detect tiny amounts of blood in sea water Eyes, ears, nose detect stimuli in the form of sound, light, odor, and touch Mostly found in the head Sense Organs