16.3

Question 1

Somatic sensory (somatosensory) pathways relay information from where to where

Answer 1

Relay information from SOMATIC SENSORY RECEPTORS TO PRIMARY SOMATOSENSORY AREA (post central gyrus) in the parietal lobe of the cerebral cortex to THE CEREBELLUM

Question 2

First order (primary) neurons

Answer 2

Sensory neurons that conduct impulses from somatic sensory receptors into the brain stem or spinal cord

Question 3

Second order (secondary) neurons? Conduct impulses from the ___ to the ____

Answer 3

From the brain stem or spinal cord to the thalamus

Question 4

Axons of second order neurons do what as they course through the brain stem or spinal cord before ascending to the thalamus?

Answer 4

Decussate (cross over to opposite side)

Question 5

Third order (tertiary) neurons conduct impulses from ____ to ____

Answer 5

From thalamus to the primary somatosensory area on the same side

Question 6

Regions within the CNS where neurons synapse with other neurons that are a part of a particular sensory or motor pathway are known as ?

Answer 6

Relay stations
Because neural signals are being relayed from one region of the CNS to another

Question 7

Nerve impulses for touch, pressure, vibration and proprioception from the limbs, trunk, neck and posterior head ascend to the cerebral cortex along which pathway?

Answer 7

Posterior column-medial Lemniscus pathway

Question 8

first order neurons in the posterior column-medial lemniscus pathway extend from what into what and ascend into what

Answer 8

extend from sensory receptors in the limbs, trunk, neck and posterior head into the spinal cord and ascend to the medulla oblongata on the same side of the body

Question 9

The cell bodies of the first order neutrons are in the what of spinal nerves

Answer 9

in the posterior (dorsal) root ganglia of spinal nerves

Question 10

the axons of the first order neutrons synapse with the dendrites of the second order neutrons whose cell bodies are located in what?

Answer 10

in the gracile nucleus or cuneate nucleus of the medulla

Question 11

nerve impulses for touch, pressure, vibration & conscious proprioception from the UPPER limbs, trunk, neck & posterior head propagate along axons in the _____ and arrive at the _____

Answer 11

cuneate fasciculus , cuneate nucleus

Question 12

Nerve impulses for touch, pressure, vibration, and copious proprioception from the LOWER limbs, trunk propagate along axons in the ____ and arrive at the ____

Answer 12

gracile fasciculus, gracile nucleus

Question 13

the axons of the second-order neurons cross to the opposite side of the medulla and enter the ?

Answer 13

medial lemniscus ( a thin ribbon like projection tract that extends from the medulla to the ventral posterior nucleus of the thalamus)

Question 14

in the thalamus the axons terminals of the second-order neurons synapse with third-order neurons which project their axons to?

Answer 14

the primary somatosensory area of the cerebral cortex

Question 15

nerve impulses for pain, temperature, itch and tickle from the limbs, trunk & posterior head ascend to the cerebral cortex along which pathway?

Answer 15

anterolateral (spinothalamic) pathway

Question 16

the cell bodies of the first order neurons are in the ?
(for spinothalamic pathway)

Answer 16

posterior root ganglion

Question 17

the axon terminals of the first order neurons synapse with the second order neurons whose cell bodies are in the?

Answer 17

posterior gray horn of the spinal cord

Question 18

the axons of the secondd order neurons cross to the opposite side of the spinal cord and then pass upward to the ?

Answer 18

brainstem

Question 19

nerve impulses for most somatic sensations (tactile, thermal and pain) from the face, nasal cavity, oral cavity and teeth ascend to the cerebral cortex along which pathway?

Answer 19

trigeminothalamic pathway

Question 20

first order neurons of the trigeminothalamic pathway extend from somatic sensory receptors in the face, nasal cavity, oral cavity and teeth into ?

Answer 20

the pons through the trigeminal (V) nerves

Question 21

the cell bodies of the first order neurons are in the

Answer 21

trigeminal ganglion

Question 22

the axons some first order neurons synapse with second order neurons in the ___? axons of other first order neurons descend into the ____ to synapse with second order neurons

Answer 22

pons, medulla

Question 23

the axons of the second order neurons cross to the opposite sides of the pons and medulla then ascend as the _____

Answer 23

trigeminothalamic tract to the ventral posterior nucleus of the thalamus

Question 24

anterior & posterior spinocerebellar pathways?

Answer 24

convey nerve impulses from proprioceptors in the trunk & lower limbs of one side of the body to the same side of cerebellum. proprioceptive input informs cerebellum of actual movements, allowing it to coordinate, smooth and refine skilled movements & maintain posture & balance