sensory systems I Flashcards
What are sense organs
structures containing receptors and interneurons that are specialised for detecting and processing particular types of stimuli
What are receptor neuron
- Are specialised to detect internal and external stimuli of a particular sensory modality, especially when stimuli change
- act as filter for stimulus information, transforming stimulus energy in neural signals that are transmitted to sensory interneurons
What is the first stage in processing sensory information
receptor neurons
Where are Photoreceptor and sensory interneurons
eye
where are Hair cells and sensory interneurons
ear
where are Pacinian corpuscle
skin
where are Olfactory receptor
nose
The CNS interpretation of the sensory modality depends on what
which lines (axons) convey the signals
Is sensory processing exlusiverly serial or hierarchical
no
Info about small receptive field
Free nerve endings, Merkel’s disc and Meissner’s corpuscle sense innervate the surface of the skin and are sensitive to stimuli in small areas of the skin
info about wide or large receptive fields
Pacinian corpuscles and Ruffini’s endings innervate deeper layers of the skin and are sensitive to stimuli over a larger areas of the skin
What is a pacinian corpuscle (in skin, muscles, detecting vibration and pressure)
a unipolar cell that extends one branch of its axon to skin and other to spinal cord
What is an afferent projection
form the dorsal root (spinal) nerve and the cell bodies are part of the dorsal root (spinal) ganglion.
Each cell varies its response over what
a fraction of the total range of stimulus intensities
Which receptor will respond if A is less sensitive than B?
A. None, because they have conflicting thresholds
B. Both, because the stimulus is in both receptive fields
C. Both, if stimulus intensity is high
D. B, if stimulus intensity is low
C,D
