CNS

Question 1

What does the limbic lobe/system consist of?

Answer 1

→ amygdala,
→ hippocampus,
→ mamillary body,
→ cingulate gyrus

Question 2

What is the limbic lobe concerned with?

Answer 2

Concerned with learning, memory, emotion, motivation and reward

Question 3

Where is the insular cortex/lobe found?

Answer 3

Deep within the lateral fissure

Question 4

What is the insular cortex/lobe?

Answer 4

Concerned with visceral sensations, autonomic control, and interoception, auditory processing, visual-vestibular integration

Question 5

How many pairs of nerves originate from the spinal chord?

Answer 5

31

Question 6

What are the 5 different classes of nerves in the spinal chord? Superior to inferior?

Answer 6

→ cervical
→ thoracic
→ lumbar
→ sacral
→ coccygeal

Question 7

How many pairs of cervical nerves?

Answer 7

8

Question 8

How many thoracic pairs of nerves?

Answer 8

12

Question 9

How many lumbar pairs of nerves?

Answer 9

5

Question 10

How many sacral pairs of nerves?

Answer 10

5

Question 11

How many coccygeal pairs of nerves?

Answer 11

1

Question 12

Where do these nerves emerge from?

Answer 12

intervertebral foramina

Question 13

What nerves emerge from above the vertebrae?

Answer 13

C1-C7

Question 14

What nerves emerge from below the vertebrae?

Answer 14

C8-Co1

Question 15

Where down the spinal chord is there enlargement?

Answer 15

→ cervical enlargement from C3-T1

→ lumbar enlargement from L1 to S2

Question 16

Why does the spinal chord have certain areas of enlargement?

Answer 16

innervation of the upper + lower limbs

Question 17

What is the major descending pathway responsible for voluntary movement?

Answer 17

Corticospinal tract

Question 18

What are the major ascending pathways for sensation?

Answer 18

Dorsal column pathway + spinothalamic tract

Question 19

What is the corticospinal tract composed of?

Answer 19

→ upper motor neurones in primary motor cortex

→ lower motor neurones in brainstem (going to head + neck muscles) + spinal cord (going to muscles of trunk + limbs)

Question 20

What kind of sensation is the dorsal column pathway responsible for?

Answer 20

fine touch, vibration, pressure and proprioception (position) from the skin and joints

Question 21

What kind of sensation is the spinothalamic tract responsible for?

Answer 21

pain, temperature (and crude touch) from the skin

Question 22

What is the main difference between the lateral and ventral spinothalamic tracts?

Answer 22

Lateral = paint + temperature
Ventral = crude touch

Question 23

How are the lateral + anterior/ventral corticospinal tracts formed?

Answer 23

→ Approx. 85% of fibres decussate in medulla to form the lateral corticospinal tract
→ rest of the 15% of fibres continue down + form anterior/ ventral corticospinal tract

Question 24

What does the lateral corticospinal tract usually control?

Answer 24

Voluntary movement in limbs + digits.

Question 25

What does the lateral corticospinal tract usually control?

Answer 25

Voluntary movement in trunk, shoulder + neck muscles

Question 26

Where does the anterior corticospinal tract decussate?

Answer 26

Doesn't, stays ipsilateral but decusrates at the level of the spinal nerve at which each pair exits.

Question 27

What is the Corticobulbulbar tract?

Answer 27

Pathway from the Primary motor cortex to the muscles of the face.

Question 28

What does the corticobulbar tract consist of?

Answer 28

upper motor neurons of the cranial nerves

Question 29

What does the corticobulbar tract do?

Answer 29

→ controls muscles of face, head + neck, terminates on motor neurons within brainstem motor nuclei. → directly innervates the nuclei for cranial nerves V, VII, IX, and XII

Question 30

Does the corticobulbar tract decussate?

Answer 30

50% of corticobulbar tract would decussate, above each relevant nuclei

Question 31

Name 4 other brainstem motor tracts.

Answer 31

→ Vestibulospinal → Tectospinal → Reticulospinal → Rubrospinal

Question 32

What does the vestibulospinal tract do?

Answer 32

provides information about head movement + position and mediates postural adjustments

Question 33

What does the Tectospinal tract do?

Answer 33

orientation of the head neck during eye movements

Question 34

What does the reticulospinal tract do?

Answer 34

controls breathingand emotional motor function

Question 35

What does the rubrospinal tract do?

Answer 35

innervates lower motor neurones of the upper limb

Question 36

How do nerve fibres enter the dorsal column pathway?

Answer 36

Via the dorsal horn

Question 37

What 2 tracts can the dorsal column pathway be divided into?

Answer 37

→ gracile tract (most medial) | → cuneate tract (more lateral)

Question 38

What information is conveyed ipsilaterally through the gracile tract?

Answer 38

Info from lower limbs + body below T6

Question 39

What information is conveyed ipsilaterally through the cuneate tract?

Answer 39

Info from upper limbs + body above T6

Question 40

Where does the dorsal column pathway first synapse?

Answer 40

In the medulla

Question 41

Where are the 2nd order axons of the dorsal column pathway? Do they decussate?

Answer 41

Through the medulla, decussate in the caudal medulla to form the contralateral medial lemniscus tract

Question 42

What is the contralateral medial lemniscus tract?

Answer 42

Tract formed after the dorsal column pathway decussates in the caudal medulla

Question 43

Where are the 2nd synapses of the dorsal column pathway?

Answer 43

In the thalamus

Question 44

Where are the 3rd order axons of the dorsal column pathway?

Answer 44

Project from thalamus to somatosensory cortex

Question 45

What is the size of each somatotopic area in the Somatosensory cortex proportional to?

Answer 45

Density of sensory receptors in that body region

Question 46

Where are the 1st synapses of the spinothalamic tracts?

Answer 46

In the dorsal horn upon entering the spinal chord

Question 47

Where do the spinothalamic tracts decussate?

Answer 47

2nd order neurones decussate immediately when entering the spinal chord to form the spinothalamic tract

Question 48

Where are the 2nd synapses of the spinothalamic tracts?

Answer 48

in the thalamus

Question 49

Where are the 3rd order axons of the spinothalamic tracts?

Answer 49

projects to the somatosensory cortex from the thalamus