Question | Answer |
What are 3 characteristics of the Reflex Arc? | 1. Simplest Functional Circuit of the NS; 2. does NOT involve the Brain; 3. produces an Immediate, INVOLUTARY motor response to stimuli |
What are the components of the Reflex Arc? | 1. Receptor; 2. Sensory Neuron; 3. Interneuron (optional); 4. Motor Neuron; 5. Effector (muscle or gland) |
What is the function of Receptors? | REPOND to SPECIFIC environmental energy forms (stimuli), internal or external |
What are the different Receptors? | 1. Photoreceptors; 2. Acoustic Receptors; 3. Mechanoreceptors; 4. Chemoreceptors; 5. Thermoreceptors |
What is the function of Receptor Potentials? | to Stimulate AP's |
name a Mechanoreceptor sensitive to pressure. | Pacinian Corpuscle |
How is a stimulus transformed into an Electrical Response? | 1. Membrane Distortion; 2. increased permeability to ALL Ions; 3. Receptor Potential; 4. AP's propagated from 1st Node |
How long are AP's propagated from a Receptor? | until Sensory receptor REPOLARIZES |
What is a Receptor Potential? | localized Depolarization |
What are 3 characteristics of Receptor Potentials? | 1. NOT all-or-none, GRADED Amplitude; 2. duration = Duration of Stimulus; 3. NOT propagated to CNS, only to 1st Node |
What determines AP Frequency? | Stimulus INTENSITY |
What determines Sensory AP Frequency? | Receptor Potential AMPLITUDE |
What is the definition of Receptor Adaptation? | a DECREASE in Sensory AP Frequency despite an UNCHANGING environmental Stimulus |
What is the function of Receptor Adaptation? | enables the CNS to devote attention to IMPORTANT/Changing Stimuli |
Which Receptors do not adapt? | Pain receptors |
Name 2 examples of Fast Adapting Receptors. | Pacinian Corpuscles, Smell |
Name 2 Slow Adapting Receptors. | Kinesthetic, Pain |
How do Fast/Slow Adapting Receptors work? | by Increasing or Decreasing AP Frequency despite unchanging environmental stimulus |