Ascending Tracts

Question 1

where are sensory receptors

Answer 1

many diff receptors are scattered throughout the body

Question 2

how can sensory receptors be activated

Answer 2

exteroceptive input

interoceptive input

proprioceptive input

Question 3

interoceptive input

Answer 3

relays info about the body’s internal state

Question 3

exteroceptive input

Answer 3

relays sensory info about the body’s interaction with the external environment

Question 4

proprioceptive input

Answer 4

conveys info about position sense from the body and its component parts

Question 5

what are the 3 different receptors able to detect

Answer 5

mechanical, chemical, nociceptive and thermal stimuli

Question 6

what are sensory reception detection converted into

Answer 6

nerve impulses

sent to CNS

Question 7

where are next level or progression further processed

Answer 7

ascending sensory pathways

Question 8

where does the info from the ascending sensory pathways go

Answer 8

cerebral cortex or cerebellum

Question 9

3 distinct ascending pathways

Answer 9

anterolateral system (ALS)

dorsal column-medial lemniscal (DCML)

somatosensory pathways to the cerebellum

Question 10

Anterolateral system

Answer 10

also known as spinothalamic tract

sensory pathway from the skin to the thalamus

Question 11

where is info from the ALS relayed

Answer 11

upward to the somatosensory cortex

Question 12

2 main parts of the spinothalamic tract (STT)

Answer 12

lateral STT

anterior STT

Question 13

anterior STT

Answer 13

transits crude touch

Question 13

lateral STT

Answer 13

transmits pain and temp

Question 14

where does the anterolateral pathway decussates

Answer 14

level of the spinal cord

usually crosses 1-2 levels above the point on injury

Question 15

anterolateral pathway provides

Answer 15

affective sensation

Question 16

affective sensation

Answer 16

sensation accompanied by a compulsion to act

ex: a painful stimulus makes us want to withdraw from the pain

Question 17

dorsal column medial lemniscus

Answer 17

sensory pathway of the CNS

Question 18

what does DCML convey

Answer 18

localized sensation of fine touch, vibration, two point discrimination, proprioception (position sense)

Question 19

where does the DCML transmit info

Answer 19

from the body tot he postcentral gyrus of the cerebral cortex

Question 20

DCML receptors are found

Answer 20

skin

joints

golgi tendon organs via 1b axons

muscles

muscle spindles

Question 21

DCML receptors in the skin

Answer 21

hair follicles

Merkel’s cells

Meissner

Pacinian or ruffini corpuscles via Ab axons

Question 22

DCML is composed of

Answer 22

gracile fasciculus

cuneate fasciculus

Question 23

gracile fasciculus

Answer 23

lower half of the body

carried fibers up to T7

arise from the fibers more medial

Question 24

cuneate fasciculus

Answer 24

upper half of the body

carries fibers from C6 and above

Question 25

DCML fibers

Answer 25

rapidly conducting

large

myelinated

Question 26

where does DCML decussate

Answer 26

medulla

Question 27

testing the DCML clinically

Answer 27

romberg’s test

Question 28

romberg’s test below decussation

Answer 28

produce loss of sensation on the same side of the body as the lesion

Question 29

romberg’s test above decussation

Answer 29

produce loss of sensation on the opposite side of the body

Question 30

spinocerebellar tract

Answer 30

a set of axonal fibers originating in the spinal cord and terminating in the ipsilateral cerebellum

Question 31

spinocerebellar tract conveys info to

Answer 31

the cerebellum about limb joint position

proprioception

Question 32

spinocerebellar tract receptors

Answer 32

muscle spindles

golgi tendon organs

joint receptors via Aa axons