Anatomy

Question 1

What is a myelin sheath?

Answer 1

Wrapped around axons to increased action potential travel

Question 2

Which cells produce myelin in the peripheral nervous system?

Answer 2

Schwaan cells

Question 3

Which cells create the myelin sheath in CNS?

Answer 3

Oligodendrocytes

Question 4

Is motor/sensory afferent or efferent?

Answer 4

Motor = efferent
Sensory = afferent

Question 5

How many spinal nerves are there and how many of each type?

Answer 5

31 pairs

• 8 cervical
• 12 thoracic
• 5 lumbar
• 5 sacral
• 1 coccygeal

Question 6

Describe the route of the sensory axons from spinal nerve to spinal cord?

Answer 6

spinal nerve –> posterior root –> posterior rootlets –> posterior horn of spinal cord

Question 7

Describe the route of motor axons from the spinal cord to the spinal nerve?

Answer 7

anterior horn of spinal cord –> anterior rootlets –> anterior root –> spinal nerve

Question 8

What do the posterior roots contain?

Answer 8

sensory fibres only

Question 9

What do the anterior roots contain?

Answer 9

motor fibres only

Question 10

Do the spinal nerves contain motor or sensory fibres?

Answer 10

both mixed together

Question 11

Which dermatome is the male nipple in?

Answer 11

T4

Question 12

Which dermatome is the umbilicus in?

Answer 12

T10

Question 13

Which dermatomes cover the scalp, neck and shoulder?

Answer 13

C2-C4

Question 14

Which dermatomes cover the upper limb?

Answer 14

C5-T1

Question 15

Which dermatomes cover the lower limb, gluteal region and perineum?

Answer 15

L2-Co1

Question 16

Which nerves are in the cervical plexus?

Answer 16

C1-C4

Question 17

Which nerves make up the brachial plexus?

Answer 17

C5-T1

Question 18

Which nerves make up the lumbar plexus?

Answer 18

L1-L4

Question 19

Which nerves make up the sacral plexus?

Answer 19

L5-S4

Question 20

Where do the sympathetic nerves exit the spinal cord?

Answer 20

T1-L2 (thoracolumbar)

Question 21

Where would you find the sympathetic chains?

Answer 21

Running the length of the vertebral column

Question 22

Where do the parasympathetic axons leave the CNS?

Answer 22

Cranial nerves 3, 7, 9 and 10

Sacral spinal nerves

Question 23

What causes Horner’s syndrome?

Answer 23

Compression of the cervical part of the sympathetic trunk

–> impaired sympathetic innervation of head + neck

Question 24

What level does the spinal cord end at?

Answer 24

L1/L2

Question 25

What is the cauda equina?

Answer 25

All the spinal nerve roots from L2 to Co1 descending to their numbered vertebrae

Question 26

In which part of the spine is the 'spinal nerve' present?

Answer 26

Intervertebral foramen

Question 27

Where is caudal anaesthesia injected?

Answer 27

Into sacral hiatus

Question 28

Which spinal nerves are contained within the femoral nerve?

Answer 28

L 2, 3, 4

Question 29

Which nerve is tested with the bicep reflex?

Answer 29

C5

Question 30

Which nerve is tested with the triceps reflex?

Answer 30

C7

Question 31

Which nerve is tested with the supinator/brachioradialis reflex?

Answer 31

C6

Question 32

Which nerve is tested with the patellar reflex?

Answer 32

L4

Question 33

Which nerve is tested with the ankle reflex?

Answer 33

S1

Question 34

Which structure links the two hemispheres?

Answer 34

Corpus callosum

Question 35

Which artery supplies the lateral part of the brain?

Answer 35

middle cerebral artery

Question 36

Which artery supplies the middle part of the brain?

Answer 36

anterior cerebral artery

Question 37

Which two main arteries feed the brain?

Answer 37

``` Internal carotid (anterior) Vertebral (posterior) ```

Question 38

Which artery is formed when the left and right vertebral arteries meet?

Answer 38

Basilar artery

Question 39

When the basilar artery splits, what does it become?

Answer 39

Posterior communicating arteries (join posterior and anterior circulation, creating Circle of Willis)

Question 40

Which artery supplies the occipital lobe?

Answer 40

Posterior cerebral artery

Question 41

Name the sensory spinal tracts

Answer 41

Dorsal column medial lemniscus (DCML) | Spinothalamic

Question 42

Name the motor spinal tract

Answer 42

Corticospinal (pyramidal)

Question 43

Which modalities are transmitted in the dorsal column?

Answer 43

Fine touch Vibration Proprioception

Question 44

Which modalities are transmitted in the spinothalamic tracts?

Answer 44

Lateral: pain and temperature Anterior: crude touch and pressure

Question 45

Where do the synapses occur in the dorsal column?

Answer 45

1st: Medulla (cuneate if above waist, gracile if below waist) 2nd: Thalamus

Question 46

Where does the second neurone decussate (cross) in the dorsal column?

Answer 46

Medulla

Question 47

Where do the synapses occur in the spinothalamic tract?

Answer 47

1st: Spinal cord (one or two levels above entrance) 2nd: Thalamus

Question 48

Where does the second neurone decussate (cross) in the spinothalamic tract?

Answer 48

Spinal cord

Question 49

Describe the pathway in the corticospinal (pyramidal) tracts:

Answer 49

1. Upper motor neurone: motor cortex --> lower medulla 2. Decussates at lower medulla, travels down 3. Synapses with lower motor neurone at anterior horn 4. Exits spinal cord at anterior horn and travels to muscle

Question 50

Where does the corticospinal tract decussate?

Answer 50

Medulla

Question 51

Name an excitatory neurotransmitter

Answer 51

Glutamate

Question 52

Name two inhibitory neurotransmitters

Answer 52

GABA | Glycine

Question 53

Which level of the spinal cord is a lumbar puncture performed?

Answer 53

L3,4 or L4,5

Question 54

Which layers does the needle pass through during a lumbar puncture?

Answer 54

``` Skin Fascia Supraspinous ligament Interspinous ligament Ligamentum flavum Epidural space Dura ```