11 Questions
Which type of sensitivity is transmitted through the spinobulbothalamocortical tract?
Fine sensitivity
Where is the 2nd neuron located in the spinobulbothalamocortical tract?
Medulla oblongata
What is the name of the tract that conducts pain, temperature, cold, tickle, and itch?
Lateral spinothalamic tract
What is the name of the crossing of the tracts in the medulla oblongata?
Sensory decussation
What is the function of the dorsal root ganglion in the spinobulbothalamocortical tract?
To serve as the 1st neuron in the tract
What is the final destination of the spinobulbothalamocortical tract?
Cerebral cortex
What is the term for the ability to detect position in space and tension in muscles and joints?
Proprioception
What is the term for the detection of pain?
Nociception
What is the meaning of the Greek word 'pathos' in the context of protopathic sensibility?
Disease
What does the Latin word 'proprius' mean in the context of proprioception?
Proper or intrinsic
What is the term for the ability to distinguish between small degrees of sensations?
Epicritic sensibility
Study Notes
Sensitive Nerve Tracts of the Body
Ascending Tracts in Posterior Funiculi of Spinal Cord
- Tracts of fine sensitivity (light touch, light vibration, recognition of two points close to each other) = epicritic sensitivity
- Spinobulbothalamocortical tract: 1st neuron – dorsal root ganglion (spinal ganglion), 1st part of tract = spinobulbar tract (spinal cord to medulla oblongata)
- Pseudounipolare cells in fasciculus gracilis and fasciculus cuneatus
- 2nd neuron – ncl. gracilis and ncl. cuneatus (in medulla oblongata), 2nd part of tract = bulbothalamic tract (to thalamus)
- Tracts cross at sensory decussation (lemniscorum) and continue as medial lemniscus to thalamus
- 3rd neuron – thalamus (ventral posterolateral + posteromedial ncl.), 3rd part of tract = thalamocortical tract (to cerebral cortex)
Tracts in Lateral and Anterior Funiculi of Spinal Cord
Lateral Spinothalamic Tract
- Conducts pain, temperature, cold, tickle, and itch
- 1st neuron – spinal ganglion to spinal cord (proper nucleus in dorsal horn of spinal cord)
- 2nd neuron – proper nucleus of dorsal horn, crossing of tracts with medial lemniscus to thalamus
- 3rd neuron – thalamus (ventral posterolateral + posteromedial ncl.), through internal capsule to postcentral gyrus of cerebral cortex
Anterior Spinothalamic Tract
- Predominates deep touch and pressure (crude sensitivity)
- 1st neuron – spinal ganglion to spinal cord (proper nucleus in dorsal horn)
- 2nd neuron – proper nucleus of dorsal horn, crossing of tracts with medial lemniscus to thalamus
- 3rd neuron – thalamus (ventral posterolateral + posteromedial ncl.), through internal capsule to postcentral gyrus of cerebral cortex
Projection Fibers
- Projection fibers transmit sensory information through two pathways: spinal nerves and cranial nerves
- Both spinal nerves and cranial nerves have ascending and descending fibers
Types of Sensibility
- Protopathic Sensibility: refers to crude sensibility, characterized by sensations that occur before the onset of disease
- Epicritic Sensibility: refers to fine sensibility, enabling distinction between small degrees of sensations
Proprioception
- Proprioception: the ability to sense position in space, tension detection in tendons, muscles, and articular capsules
- The term "proprioception" comes from the Latin "proprium", meaning proper or intrinsic, and refers to the perception of oneself
Nociception
- Nociception: the ability to detect pain, characterized by the perception of harmful sensations
- The term "nociception" comes from the Latin "noxia", meaning harmful or injurious
This quiz covers the sensitive nerve tracts of the body, including the spinobulbothalamocortical tract, spinobulbar tract, and the roles of the dorsal root ganglion and fasciculus gracilis and cuneatus.
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