Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PHTH 7303 Neuro > Exam 1 Week 3: Ascending Tracts & Local Tracts > Flashcards

Exam 1 Week 3: Ascending Tracts & Local Tracts Flashcards

1
Q

Where do the dorsal column tract decussate?

A

Both dorsal column tracts decussate in the medulla

Fasiculus Gracilis
Fasiculus Cuneatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Dorsal Spinocerebellar tract

Size

From body area

Path

Decussation

Entry into cerebellum

A

Size: large caliber & medium caliber axons

From body area: LE

Path:

  • Proprioceptive 1st degree neuron enters through dorsal horn
  • Synapses in Nucleus Dorsalis
  • Rises ipsilaterally in Lateral Funiculus
  • Enteres cerebellum through Inferior Cerebellar Peduncle

Decussation: none

Entry into cerebellum: inferior cerebellar peduncle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

The two Local (intrinsic) tracts

A

Spinospinal (propriospinal system) (1)

Lissauer’s Tract (2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Anterior Spinothalamic tract

Describe 2nd order neuron pathway

A

Anterior Spinothalamic Tract

  • Synapses in Nucleus Proprius
  • Transmits crude (non-discrimitive) touch & pressure
  • Decussates immediately in ventral white commussure
  • Ascends in ventral funiculus
  • Ends in thalamus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Function of all the Spinocerebellar tracts

A

Unconscious proprioception information:

(Convey proprioceptive, touch and pressure info to the cerebellum to use in correction of movment.)

UNLIKE: Conscious proprioception that goes into the cerebral cortex, such as what tells you the location of your joints.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Spinothalamic Tracts: Everything

A

Also called anterolateral pathway/system

Two Tracts

  • Lateral Spinothalamic Tract
  • Anterior (ventral) spinothalamic Tract

Describe Pathways:

  • 1st order neuron
    • (cell body in DRG) enters through dorsal root.
    • Descends or Ascends 1-2 segments before synapsing
      • in Lissaur’s tract
  • 2nd order neuron (tract neuron)
    • Lateral Spinothalamic Tract
      • Synapses in Substantia Gelatinosa
        • Transmits pain & temperature
      • Decussates immediately in ventral white commissure
      • Ascends in ventrolateral funiculus
      • Ends in Thalamus
    • Anterior Spinothalamic Tract
      • Synapses in Nucleus Proprius
        • Transmits crude (non-discrimitive) touch & pressure
      • Decussates immediately in ventral white commussure
      • Ascends in ventral funiculus
      • Ends in thalamus
  • 3rd order neuron
    • Synapse in thalamus
    • end in
      • primary somatosensory cortex
      • cingulate cortex
      • insular cortex

Function:

  • Lateral Spinothalamic Tracts
    • Pain
    • Temperature
  • Anterior Spinothalamic Tracts
    • Crude touch (non-discriminant touch)
    • pressure

Somatotopic Relationship:

  • LE: lateral
  • UE: medial
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Dorsal Tract Columns: Describe pathway and other relevant details

A

Describe pathway and other relavant details:

Primary unipolar afferents with cell bodies in dorsal ganglia. They enter dorsal horn and travel the gracilis and cuneate tracts as primary affernets without synapsing until they reach the Medulla. They are arranged with a Somatotopic relationship. Afferents from LE travel medially in the Fasciculus Gracilis, synapse with secondary neurons in the Nucleus Gracilis (which can be seen as the Gracile Tubercle) in the medulla. Likewise, afferents from the UE travel laterally in the Fasciculus Cuneatus and synapse with secondary neurons in the Nucleus Cuneatus (which can be seen as the Cuneate Tubercle) in the Medulla. Secondary neurons for both tracts synapse with tertiary neruons in the Thalamus. The tertiary neurons end in the Somatosensory Cortex in the Post-Central Gyrus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which Ascending Tracts decussate and end contralaterally?

A
  1. Fasiculus Gracilis
  2. Fasiculis Cuneatus
  3. Lateral Spinothalamic tract
  4. Medial Spinothalamic Tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Two Spinothalamic Tracts

A
  1. Lateral Spinothalamic Tract
  2. Anterior (ventral) spinothalamic tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which ascending tracts decussate?

A

Both Dorsal Tracts (in the medulla)

  1. Fasiculus Gracilis
  2. Fasiculus Cuneatus

Both Spinothalamic Tracts (in the ventral white commisure of the spinal cord)

  1. Lateral Spinothalamic tract
  2. Medial Spinothalamic tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Lateral spinothalamic tract:

Describe 2nd order neuron pathway

A

2nd order neuron (tract neuron)

Lateral Spinothalamic Tract

  • Synapses in Substantia Gelatinosa
  • Transmits pain & temperature
  • Decussates immediately in ventral white commissure
  • Ascends in ventrolateral funiculus
  • Ends in Thalamus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Intrinsic tracts: Where do axons ascend & descend?

A

Axons Ascend & Descned in:

  • Propriospinal bundles which are immediately adjacent to gray matter)
    • Dorsal propriospinal bundles
    • Lateral propriospinal bundles
    • Ventral Propriospinal bundles
  • Lissauer’s tract (limited extent
    • at dorsal end of tip of dorsal horn
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Intrinsic tracts: Functions

A
  • Link spinal segments
  • Allow for motor coordination between spinal levels
    • produce multi-limb reflexes
    • help with coordination of limbs during gait
  • Allow for sensory effects to be spread over many spinal segments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which Ascending Tracts decussate and end ipsilaterally?

A

Ventral Spinocerebellar tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Intrinsic tracts: origin

A

Originate form a varitey of sources, including:

  • Posteromarginal nuclei
  • Ventral Motor Nuclei
  • Inter-nuclear neurons between nuclei of spinal gray
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Spinothalamic Tracts:

Describe Pathways

A

Also called anterolateral pathway/system

Describe Pathways:

1st order neuron

  • (cell body in DRG) enters through dorsal root.
  • Descends or Ascends 1-2 segments before synapsing
    • in Lissaur’s tract

2nd order neuron (tract neuron)

  • Lateral Spinothalamic Tract
    • Synapses in Substantia Gelatinosa
    • Transmits pain & temperature
    • Decussates immediately in ventral white commissure
    • Ascends in ventrolateral funiculus
    • Ends in Thalamus
  • Anterior Spinothalamic Tract
    • Synapses in Nucleus Proprius
    • Transmits crude (non-discrimitive) touch & pressure
    • Decussates immediately in ventral white commussure
    • Ascends in ventral funiculus
    • Ends in thalamus

3rd order neuron

  • Synapse in thalamus
  • ends in
    • primary somatosensory cortex
    • cingulate cortex
    • insular cortex
13
Q

Spinothalamic tracts: Function

A

Function:

Lateral Spinothalamic Tracts

  • Pain
  • Temperature

Anterior Spinothalamic Tracts

  • Crude touch (non-discriminant touch)
  • pressure
14
Q

Dorsal Colum tracts: Everything

A

There are two:

  1. Fasciculus Gracilis
  2. Fasiculus Cuneatus

Describe pathway and othe relavant details:

  • Primary unipolar afferents with cell bodies in dorsal ganglia. They enter dorsal horn and travel the gracilis and cuneate tracts as primary affernets without synapsing until they reach the Medulla. They are arranged with a Somatotopic relationship. Afferents from LE travel medially in the Fasciculus Gracilis, synapse with secondary neurons in the Nucleus Gracilis (which can be seen as the Gracile Tubercle) in the medulla. Likewise, afferents from the UE travel laterally in the Fasciculus Cuneatus and synapse with secondary neurons in the Nucleus Cuneatus (which can be seen as the Cuneate Tubercle) in the Medulla. Secondary neurons for both tracts synapse with tertiary neruons in the Thalamus. The tertiary neurons end in the Somatosensory Cortex in the Post-Central Gyrus.

Function:

  • Mediates sensory modalities of Fine, discriminative touch and proprioception.
14
Q

Intrinsic tracts: Types of connections (2)

A

Ipsilateral

Commissural

16
Q

Name the two dorsal colum tracts

A
  1. Fasciculus Gracilis
  2. Fasciculus Cuneatus
18
Q

Where do the spinocerebellar tracts decussate?

A

The following three don’t dessucate at all:

  1. Dorsal Spinocerebellar tract
  2. Rostral Spinocerebellar tract
  3. Cuneocerebellar tract

They run directly ipsilaterally into the cerebellum.

The Ventral Spinocerebellar tract decussates twice:

  1. Decussates in spinal cord right after synapsing with 2nd order neuron
  2. Decussates in midbrain before descending into the cerebellum
19
Q

What are local (intrinsic) tracts?

A

Tract axons go from one segment to another over very few segments.

22
Q

The Spinothalamic tracts are also known as

A
  • anterolateral pathway (used by Dr. Lake when explaining). Also referred to as system.
  • ventrolateral system
23
Q

Rostral Spinocerebellar tract

From body area:

Path:

Decussation:

Entry into cerebellum:

A

Similar to Dorsal Spinocerebellar tract but for UE

From body area: UE

Path:

  • Proprioceptive 1st degree neuron enters through dorsal horn
  • Synapses on base of dorsal horn (instead of nucleus dorsalis)
  • Rises ipsilaterally in Lateral Funiculus
  • Enteres cerebellum through Inferior Cerebellar Peduncle

Decussation: none

Entry into cerebellum: inferior cerebellar peduncle

24
Q

Ventral Spinocereellar tract

Size:

From body area:

Path:

Decussation:

Entry into cerebellum: i

A

Size: large caliber & medium caliber axons

From body area: LE

Path:

  • Proprioceptive 1st degree neuron enters through dorsal horn
  • Synapses at base of dorsal horn
  • Decussates
  • Rises in contralateral Lateral Funiculus
  • Decussates again in midbrain
  • Enteres cerebellum through Superior Cerebellar Peduncle

Decussation:

  • right after entering spinal cord
  • In midbrain

Entry into cerebellum: superior cerebellar peduncle

25
Q

Dorsal Tract Columns: function

A

Function:

Mediates sensory modalities of fine, discriminative touch and proprioception.

26
Q

Where do the spinothalamic tracts decussate?

A

Both Spinothalamic Tracts decussate in the ventral white commisure of the spinal cord

Lateral Spinothalamic tract
Medial Spinothalamic tract

28
Q

Name the 8 White Ascending Tracts?

A
  • Dorsal Column/Funiculus
    • Fasciculus Gracilis (1)
    • Fasciculus Cuneatus (2)
  • Lateral Columns
    • Spinothalamic Tracts
      • Lateral Spinothalamic Tract (3)
      • Anterior (Ventral) Spinothalamic Tract (4)
    • Spinocerebellar Tracts
      • Dorsal Spinocerebellar Tract (5)
      • Ventral Spinocerebellar Tract (6)
      • Rostral Spinocerebellar Tract (7)
      • Cuneo-Spinocerebellar Tract (8)

Note: Sometimes it is said that there are 7 ascending tracts if the dorsal tracts are counted as one.

29
Q

Which Ascending Tracts DO NOT decussate and end ipsilaterally?

A
  1. Dorsal Spinocerebellar tract
  2. Rostral Spinocerebellar tract
  3. Cuneocerebellar tract
30
Q

Spinothalamic tracts: Somatotopic?

A

Yes

Somatotopic Relationship:

LE: lateral
UE: medial

31
Q

Cuneocerebellar tract

From body area:

Path:

Decussation:

Entry into cerebellum:

A

Similar to Fasiculus Cuneatus, except no decussation, goes to cerebellum, and carries just proprioception

From body area: UE

Path:

Proprioceptive 1st degree neuron enters through dorsal horn
Rises without synapsing in the fasciculus cuneatus
Synapses with 2nd order neuron in Accessory Cuneate Nucleus of caudal Nedulla
Enteres cerebellum through Inferior Cerebellar Peduncle

Decussation: none

Entry into cerebellum: inferior cerebellar peduncle

PHTH 7303 Neuro (89 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions