Sensory Physiology Flashcards
What is the function of sensory physiology?
The function of sensory physiology is to allow us to interact with the world around us and transduce/convert different types of energy into electrical signals called action potentials.
What happens first in the initiation of a sensory AP?
Different types of energy are detected by sensory receptors - leads to the generation of AP.
Where is the detected receptor energy sent to in the brain?
It is sent to the the parietal lobe.
Where does perception start?
Perception starts with the stimulation of sensory receptors, each of which responds to a certain stimulus.
What type of sensation does the chemoreceptors detect?
Chemical changes
What is the major sensory organ of the body?
The skin
What type of sensation does the photoreceptors detect?
Light, in retina for vision.
What type of sensation does the mechanoreceptors detect?
Pressure
What type of sensation does the nociceptors?
Noxious stimuli (generate pain)
What type of sensation does the proprioreceptors detect?
Information about the body and limb position - important for control of movement.
What are the two subcategories of sensory receptors?
Sensory receptors can be rapidly adapting or slowly adapting. Slowly adapting receptors continue to discharge as long as the receptor is being stimulated, whereas rapidly adapting receptors don’t….. discharge is reduced or may cease.
What are some examples of skin receptors in the skin?
- Pacinian Corpuscle
- Meissner’s Corpuscle
- Ruffini endings
Which direction do AP move along a sensory neuron?
From the receptors TOWARDS the CNS.
What is a receptor field?
A receptive field of a sensory neuron is the area of skin that once stimulated produces a response in that neuron. These fields are of varying size and inversely with numbers of receptors in the area. SMALLER in areas requiring greater sensitivity.
Are the sensory neurons of the body myelinated?
Yes; travel very fast to brain.
What is the two-point discrimination test?
Compass - two points to one point if can feel for all the movement is a highly sensitive receptive field.
What does the two-point discrimination test detect:
It is a measure of tactile acuity - small receptive fields in areas of skin with large numbers of cutaneous receptors.
What do generator receptor potentials detect?
They detect local graded changes in membrane potential.
How are sensory triggered action potentials initiated?
When generator potentials reach threshold for depolarization. The bigger the stimulus the greater the number of action potentials generated.
Why is the thalamus important?
It is important relay centre in the brain.
Why does sensory information reach our sensory cortex?
This is so we have a conscious perception of a sensation
What are the two main sensory tracts (Touch and Temperature) to the brain?
Medial Lemniscal tract (touch) Spinothalamic tract (temperature)
Where does the sensory innervation of the face occur?
The sensory innervation of the mainly via sensory fibers of the TRIGEMINAL NERVE (Cranial nerve V)
Where do sensory neurons of the face synapse?
In the brainstem nuclei, including the main sensory trigeminal nucleus and the mesencephalic nucleus of the trigeminal nerve on to the thalamus via the TRIGEMINOTHALAMIC TRACT and finally to the SOMATOSENSORY CORTEX.
