Skin and touch

jozalesa's version from 2016-12-16 11:52

Section 1

Question Answer
What is touch?Tactile sensation
What are tacticle sensations?size, shape, texture
What specialized receptor cells detect strong pressure or vibrationmechanoreceptors
What specialized receptor cells are sensitive to temperaturethermoreceptors
What perception is discrimitive touch based uponpressure, vibration and texture

Section 2

Question Answer
Name the different sensory receptors associated with discrimitive touchhair follice ending, meissner's corpuscle, merkel's disc, ruffini ending, pacinian corpuscle, free nerve endings
Where are hair follic ending receptors and what is their function?Wrapped around hair follile. Respond to displacement of hair
Where are Meissner's corpuscle receptors and what is their function?Dermis of the skin. Respond to vibration (low frequency) so are sensitive to fine touch
Where are Merkel's disc's and what is their function?Dermis of skin. Respond to pressure so are sensitive to light tactile stimuli/pressure
Where are Ruffini ending receptors and what is their functionDermis of skin. Respond to skin stretch so sensitive to pressure
Where are pacinian corpuscle and what is their functionDermis of skin. Respond to vibration (high frequency) so are sensitive to pressure
Where are free nerve endings and what are their function?There are various types of free nerve endings found througout the skin. The responds to mechanical, thermal or noxious stimuli

Section 3

Question Answer
What are the receptor cells in muscles and joints that are triggered in response to movement of these tissues, so giving us the sense of body awarenessProprioception
What is proprioceptionThe ability to sense the location, position, orientation and movement of the body and its parts in space
What is a nociceptorReceptor neuron that is preferentially sensitive to a noxious stimulus (causing dmage to normal tissue) or a stimulus that would become noxious if prolonged
What is tissue damage detected byNerve ending called nociceptors
Where are nociceptors locatedThroughout all parts of the body except the brain
What do nociceptors detect?All types of pain (superificial) - i.e. caused by injury to the skin. They detect deep somatic pain originating from muscles, joints, tendons and blood vessels, and the detect visceral pain that originates from body organs.

Section 4

Question Answer
What is neuralgiaNeuropathic pain
What is neuropathic painCommonly called neuralgia. Pain that results from damaged neurons. The original trauma in the area may have damaged muscle for example, which has long since healed, but damage to the nerves may be long-term or permanent.
What can neuropathic pain do with regard to transmission of informationIt can disrupt the correct transmission of information

Section 5

Question Answer
What happends once pain has been detected by nociceptorsThe neural signal is transmitted towards the spinal cord and the signal crosses over almost immediately
What is the pathway for detecting heat calledSpinothalmic tract
What happens to sensory information (heat or pain)The ascending fibres relay sensory information up to the brain.
What do the descending pathways do (heat or pain)?Relay motor information to control the response within muscle.
What is the difference between heat/pain pathways and other sensations such as tactile, joint position and vibration?Sensory information is relayed along the dorsal column-medial lemniscal tract and upto the brainstem (medulla) before crossing over.
When do heat/pain pathways cross over?almost immediately
Where does all information sensory information pass through?The thalamus and then onto the somatosensory cortex
What does the somatosensory cortex do?Localizes the origin of the stimulus
What happens to the message once is has been processed in the brainAn appropriate response is sent back down the spinal cord and towards a muscle group to elicit the necessary set of actions (this is the corticospinal pathway)
What is the corticospinal pathway?Pathy of neurons that start in the motor cortex and run to a speific location in the spinal cord. Either to motor neurons themselves or to local interneurons that then make contact with the motor neurons

Section 6

Question Answer
How is our perception of smell and our perception of taste closely associatedBoth depend on the detection of chemicals at specialized receptors and both influence activity within the limbic brain centres, which govern memory and emotion
What is acute painShort term and usually has an identifiable cause
What is chronic painlong-term and not necessarily associated with any identifiable form of injury or disease