1. Sense Receptors Receptor: a simple nerve ending Sense organ: a nerve ending that is connected to tissue to limit or enhance a response Sensory transduction: process of converting stimulus to nerve energy

2. Sense Receptors Modality: Type of stimulus, all action potentials are the same, but the brain processes them differently based on neuron fiber that carries them Location: two types 1. Receptive field: the area that a single neuron is responsible for stimulus transduction. Different areas of body are more sensitive then others

3. Sense Receptors 2. Sensory Projection: to identify site of stimulation Intensity: based on # and kinds of neurons and time intervals of actions potentials

4. Sense Receptors Duration: two types 1. Phasic receptors: generate large burst of AP’s at first, then sharply reduce or adapt, even if stimulus continues (smell, hair) 2. Tonic receptors: adapt slowly, generate impulses more steadily, (muscle tension, joint motions)

5. Types of Receptors Modality: 1. Chemoreceptors: respond to odors, tastes and body fluid composition 2. Themoreceptors: respond to heat and cold 3. Nociceptors: pain receptors, trauma, ischemia, heat and chemicals 4. Mechanoreceptors: Touch, pressure, stretch, tension

6. Types of Receptors 5. Photoreceptors: respond to light Origins of stimuli 1. Interoceptors: from internal areas of body 2. Proprioceptors: position and movements 3. Exteroceptors: external to body

7. Types of Receptors Receptors in the body 1. General senses: skin, touch, internal, pain, stretch, etc 2. Special senses: limited to the head, vision, hearing, balance, taste, smell