Question

explain the physiology of ascending pathways by selecting the correct word or phrase in the blanks to complete the sentences. 1. a feather is rubbed over a section of skin on the palm of the hand, eliciting an action potential that was generated from neurons associated with click to select. 2. action potentials traveling in the posterior root reach the synapse with second - order neurons located in the click to select of the spinal cord. 3. the transfer of electrical signals between first and second - order neurons occurs click to select. 4. second - order neurons ascend the spinal cord in the click to select. 5. arriving on the click to select side of the thalamus, action potentials are transferred to third - order neurons. 6. third - order neurons arrive in the click to select cortex, where conscious comprehension occurs. click to select anterior horn contralateral ipsilateral posterior horn primary somatosensory prior to decussation spinoreticular tract spinothalamic tract tactile corpuscles

Explanation:

1. Tactile corpuscles are sensory receptors in the skin that can be stimulated by light touch like a feather - rub, generating action potentials in associated neurons.
2. Second - order neurons in the spinal cord receive signals from first - order neurons at the posterior horn.
3. Signal transfer between first and second - order neurons occurs prior to decussation.
4. Second - order neurons ascend the spinal cord in the spinothalamic tract.
5. Action potentials cross over (decussate) and arrive on the contralateral side of the thalamus.
6. Third - order neurons carry the signals to the primary somatosensory cortex for conscious perception.

Answer:

1. tactile corpuscles
2. posterior horn
3. prior to decussation
4. spinothalamic tract
5. contralateral
6. primary somatosensory