Lecture 29: Sensory Flashcards
What are the 4 somatic sensations?
- Pain
- Touch
- Warm & cold
- Body position = Proprioception
What are the 5 special senses?
-
- Balance
- Smell
- Vision
- Hearing
- Taste
What four types of info describe a sensory stimulus?
- Modality
- Duration
- Intensity
- Location
How does modality describe a stimulus
WHAT THE STIMULIS IS
- specialised receptor for each individual sensation
- —–> type of receptor activated
How does location describe a stimulus?
WHERE THE STIMULIS IS
- receptive field
How does duration describe a stimulus?
HOW LONG STIMULUS LASTS FOR
- receptors adapt over time to continuous stimulation
How does intensity describe a stimulus?
THE STRENGTH OF THE STIMULIS
- the more intense the stimuli the more AP’s the brain receives
What part of the brain is sensory info sent to?
Somatosensory cortex
Where does all sensory information synapse at?
THALAMUS
What are the two sensory pathways?
- Medial lemniscal pathway - Dorsal column tract
- Lateral spinothalamic tract
What sensory info does the medial leminscal / dorsal column tract carry?
Afferent pathway used for touch fine touch, vibration & body position/proprioception
What sensory info does the lateral spinothalamic pathway carry?
Afferent pathway for PAIN, temperature & crude touch
How many neurons do both sensory pathways have?
3 neuron which synapse 2x
Where does the medial lemniscal pathway synapse?
In medulla then crosses to the thalamus
Where does the lateral spinothalamic pathway synapse?
In spinal cord then in the thalamus
