Spinal Cord Ascending System : (DCP and STT)

Question 1

Information carried by the Dorsal Column Pathway

Answer 1

2-point discrimination

vibration sense

proprioception (helps you know where your hands and limbs are in the dark)

Question 2

Receptors for DCP

Answer 2

2 point discrimination: Meissner’s corpuscle

Vibration: Pacinian Corpuscle

Joint position: Joint receptors

Question 3

morphology of midbrain cross section:

Answer 3

upside mickey mouse called cerebral peduncles

Question 4

cerebral peduncles

Answer 4

they connect the midbrain to the cerebral cortex

Question 5

substantia naigra

Answer 5

blacks substance found in the midbrain.

produces dopamine

responsible for Parkinson’s when it is damaged

Question 6

Pathway of information via the DCP

Answer 6

first order fibers: synapse in the nucleus cuneatus in medulla

second order fibers: (travels through the medial lemniscus) synapse in the thalamus

third order fibers: synapse in area 312 of the cortex

Question 7

where in the central cortex is most of the sensory information located?

Answer 7

Postcentral Gyrus

Question 8

Pre central Gyrus

Answer 8

Motor information

Question 9

Area 4

Answer 9

precentral gyrus

Question 10

area 312

Answer 10

postcentral gyrus

Question 11

area 17

Answer 11

vision

Question 12

functional component carried in DCP

Answer 12

GSA

Question 13

What senses position, vibration and pain in the head?

Answer 13

Trigeminal ganglion

DCP does not sense pain and vibration, proprioception in the head

Question 14

nucleus cuneatus

Answer 14

nucleus in the medulla where the first order axons from upper limb synapse.

No fascilculus cuneatus after T6.

Question 15

medial lemniscus (ribbon)

Answer 15

made up of thousands of axons from DCP that pile up in the midline of the medulla.

Question 16

nucleus of second order axons

Answer 16

Ventral Posterior Lateral nucleus. (VPL)

Location: thalamus

Question 17

stroke/injury to the right thalamus

Answer 17

loss of sensation on the left side (opposite side)

Question 18

knife wound on the right side of the spinal cord (DCP)

Answer 18

loss of sensation on the right side (same side)

Question 19

third order axons termination

Answer 19

area 312 of the post central gyrus.

location: cortex

Question 20

internal arcuate fibers

Answer 20

name for the fibers of second order fibers

crosses the midline

Question 21

nucleus gracilis

Answer 21

handles lower limb sensory information.

location: medulla.

The rest of the lower limb DCP is the same as upper limb.

Question 22

fasciculus cuneatus

Answer 22

first order neurons that transmits information from C1-T6 to the medulla.

used by DCP and Dorsal spinocerebellar tract

location: spinal cord (C1-T6).

Question 23

fasciculus cuneatus vs nucleus cuneatus

Answer 23

fasciculus cuneatus: axons located in the spinal cord

nucleus cuneatus: cell bodies located in the medulla

Question 24

Tabes Dorsalis

Answer 24

wipes out the dorsal column pathway

Question 25

Positive Romberg's sign

Answer 25

Loss of proprioception: patients cannot stand steadily when their eyes are closed. Indicates problems with DCP

Question 26

Draw the DCP

Answer 26

Draw the damn thing

Question 27

Spinothalamic Tract (STT)

Answer 27

classic PAIN pathway.

Question 28

Pathway of Spinothalamic tract

Answer 28

first order synapse in Nucleus Proprius of Spinal Cord. Second order fibers cross the midline at spinal cord and synapse in the VPL 3rd order fibers synapse in Area 312 of the cortex

Question 29

Laterality of DCP

Answer 29

contralateral once it crosses midline at medulla. crosses midline at medullary level

Question 30

Laterality of Spinothalamic tract

Answer 30

contralateral at spinal cord level. Crosses midline at spinal cord level

Question 31

myelination of pain sensory fibers

Answer 31

lightly myelinated: enter spinal cord via LATERAL DiVISION

Question 32

Lateral Division of Dorsal Root Afferent

Answer 32

Entrance of: Pain fibers Temperature Light Touch visceral afferents

Question 33

lesion of DCP at spinal cord level

Answer 33

ipsilateral: loss of sensation on the same side of the body

Question 34

lesion of DCP at the brain

Answer 34

contralateral: loss of sensation on the opposite side

Question 35

lesion of Spinothalamic tract at spinal cord level

Answer 35

contralateral: loss of sensation on the opposite side of the body.

Question 36

lesion of spinothalamic tract at brain level

Answer 36

contralateral loss of sensation

Question 37

Syphilis

Answer 37

Wipes out posterior column (of Dorsal Column Pathway) and Dorsal Root Ganglion