Senses Pt1 Wk3 Flashcards
What is the difference between a sensory receptor and a sense organ?
Sensory receptors - specialised epidermal cells that respond to environmental stimuli and consist of structural and support cells that produce the outward form of the receptor, and the internal neural dendrites that respond to specific stimuli
Sense organs e.g. eyes, ears, tongue, skin and nose, help protect the body. The human sense organs contain receptors that relay information through sensory neurones to the appropriate places within the nervous system.
Do sensory receptors respond to all stimuli or are they selective?
Receptors are selective – they respond to light (photoreceptors), mechanical forces (mechanoreceptors), changes in temperature (thermoreceptors) and presence of chemicals (chemoreceptors).
Where do the stimuli that receptors respond to originate? Is it only from outside of the body?
Exteroreceptors – outside the body, e.g. light and sound.
Interoreceptors – inside the body e.g. responsive to blood pressure or sense of body position.
How can sensory receptors be classified?
Chemoreceptors, thermoreceptors, mechanoreceptors, photoreceptors.
What is a sensory modality?
An aspect of a stimulus or what is perceived after a stimulus – they include light, sound, taste, temperature,
pressure and smell.
How do sensory receptors, which are located in the periphery, inform the brain of what is going on outside/inside the body?
They send electrical signals from the periphery to the CNS of what is going on from the sensory neurones to motor, to effector.
How can the sensory receptors code that one sound is louder than another, or whether one of our muscles is stretched a lot or just a little?
Different receptors detect different stimuli i.e. Krause end bulbs that detect cold and Ruffini endings that detect warmth.
The brain is constantly being bombarded by information from both outside and within the body. It uses this information to guide any appropriate reactions. As a simple illustration of the kinds of sensory input which the brain is constantly having to deal with, can you think of which sensory receptors might be activated in the “sensory scenario” below?
Touch receptors in the fingers Sound-detecting receptors in the ears Vestibular (or balance) receptors Proprioreceptors in the joints of the arm Vision (photo)receptors Pain receptors Temperature receptors Olfactory receptors Taste receptors Mechanoreceptors in the gut Blood gas receptors and baroreceptors (blood pressure) in the cardiovascularsystem Mechanoreceptors in the bladder wall Vestibular receptors
