Sensory Pathways Study Guide

1. A stimulus activates a ___________, causing the transduction of the stimulus into a graded potential.

sensory receptor

2. When the graded potential in a sensory neuron reaches threshold, a nerve impulse is propagated in the ___________________. If the impulse is from the face, mouth, teeth or eyes the neuron is part of a _________ nerve. If the impulse is from neck, trunk, limbs, or posterior head, the neuron is part of a ________ nerve.

first-order sensory neuron, cranial, spinal

3. The action potential is then propagated from the sensory receptor into the CNS. In either the ________ or __________, this neuron will synapse with a second sensory neuron called the __________________.

spinal cord or the brainstem, second-order sensory neuron

4. This neuron will decussate and propagate the action potential from the site of synapse to the thalamus. In the thalamus, this neuron synapses with the _____________.

third-order neuron

5. The action potential is the propagated to the ______________ on the cerebral cortex.

primary somatosensory area

What is the nerve impulse type for the Posterior-Column Medial Lemniscus Pathway

Tactile sensations and conscious proprioception

What is the sensory receptor location for the posterior-column medial lemnicus pathway

Limbs, trunk, neck, posterior head

What is the site of the first synapse for the posterior-column medial lemnicus pathway

medulla oblongata

what is the site of the second synapse for the posterior-column medial lemnicus pathway

thalamus

What is the nerve impulse type for the spinothalamic pathway

Pain, itch, tickle, and temperature

What is the sensory receptor location for teh spinothalamic pathway

Limbs, trunk, neck, posterior head

What is the site of the first synapse for the spinothalamic pathway

posterior gray horn of spinal cord

what is the site of the second synapse for the spinothalamic pathway

Thalamus

What is the nerve impulse type for the Trigeminothalamic pathway

Tactile sensations, pain, itch, tickle, and temperature

What is the sensory receptor location for the trigeminothalamic pathway

Face, nasal cavity, oral cavity, and teeth

What is the site of the first synapse for the trigeminothalamic pathway

Pons or Medulla Oblongata

What is the site of the second synapse for the trigeminothalamic pathway

Thalamus

What is the nerve impulse type for the spinocerebellar pathway

Unconscious proprioception

What is the sensory receptor location for the spinocerebellar pathway

trunk and lower limbs

What is the site of the first synapse for the spinocerebellar pathway

Posterior gray horn of the spinal cord

What is the site of the second synapse for the spinocerebellar pathway

cerebellum