01/28 General Sensation

Question 1

What is the pathway for sensation of pain and temperature, from skin to sensory cortex?

Answer 1

1) Pain/temperature receptors in the dermis and epidermis
2) Dorsal root ganglion
3) Dorsal horn of the spinal cord
4) Lateral column of the spinal cord
5) Lateral spinothalamic tract
6) Ventral posterior lateral (VPL) nucleus of the thalamus
7) Post central gyrus (primary sensory cortex)

Question 2

What is the pathway for sensation of pressure and crude touch, from skin to sensory cortex?

Answer 2

1) Receptors in the dermis
2) Dorsal root ganglion
3) Dorsal horn of the spinal cord
4) Ventral spinal cord
5) Ventral spinothalamic tract
6) VPL nucleus of the thalamus
7) Post central gyrus

Question 3

What is the pathway for proprioception and sensation of fine touch and vibration, from receptors to sensory cortex?

Answer 3

1) Receptors in the muscles, joints, and tendons
2) Dorsal root ganglion
3) Ipsilateral dorsal white column
4) Fasciculus gracilis (lumbosacral input) and fasciculus cuneatus (thoracocervical input)
5) Nucelus gracilis and nucleus cuneatus in the lower medulla
6) Medial lemniscus (midbrain)
7) VPL nucleus of the thalamus
8) Post central gyrus

Question 4

What is the pathway for sensation from the face?

Answer 4

1) Trigeminal nerve (opthalmic, maxillary, and mandibular divisions)
2) Trigeminal ganglion (in the pons) and nucleus (in the medulla)
3) Fibers cross and ascend to the ventral posterior medial (VPM) nucleus of the thalamus