Anatomy

Question 1

What are 2 components of CNS?

Answer 1

• brain

- spinal cord

Question 2

What 3 components make up the PNS?

Answer 2

• spinal nerves
• cranial nerves
• autonomic nerves

Question 3

What is the difference between a nucleus and a ganglion?

Answer 3

Nucleus is a collection of nerve cell bodies in the CNS

Ganglion is a collection of nerve cell bodies in the PNS

Question 4

What is a multipolar neuron and where is its cell body?

Answer 4

• has 2 or more dendrites

- cell body is in CNS

Question 5

What is a unipolar neuron and where is its cell body?

Answer 5

• single process comes from cell body that splits into dendrite and axon
• cell body in PNS

Question 6

What type of neurons are the motor neurones of skeletal muscle and autonomic nervous system?

Answer 6

Multipolar

Question 7

What are unipolar neurons also known as in the body?

Answer 7

Sensory or pseudounipolar neurons

Question 8

What is the difference between a tract and a nerve?

Answer 8

• Tract is a collection of axons in the CNS

- Nerve is a collection of axons in the PNS

Question 9

What are single modality and mixed modality nerves?

Answer 9

Single modality nerve has only one type of nerve axons in it e.g. parasympathetic only
Mixed modality nerves carry multiple types of axons

Question 10

Most nerves are single modality nerves and tracts tend to consist of multiple modality nerves. True/false?

Answer 10

False.

Most nerves mixed modality and tracts are mostly single modality.

Question 11

How many pairs of spinal nerves are there and how many of these are cervical?

Answer 11

• 31 pairs

- 8 cervical

Question 12

At which point are the nerves that exit the spine actually only known as spinal nerves?

Answer 12

At the intervertebral foramen

Question 13

Cervical spinal nerves C1-C8 are named according to the vertebrae sitting above them while the rest are named according to vertebrae below. True/false?

Answer 13

True

Question 14

What parts of the body do the posterior and anterior rami supply?

Answer 14

• Posterior rami supplies the posterior

- Anterior rami supplies the anterolateral

Question 15

Which roots do sensory axons enter spinal cord and which roots do motor axons exit?

Answer 15

• Sensory axons enter posterior (dorsal) roots, rootless and horn
• Motor axons exit anterior horn, rootless and roots

Question 16

Rami are single modality nerves. True/false?

Answer 16

False, they are mixed modality.

Question 17

What is a dermatome?

Answer 17

Area of skin supplied with sensory innervation from single spinal nerve

Question 18

What is a myotome?

Answer 18

Group of skeletal muscles supplied with moron

innervation from single spinal nerve

Question 19

What do the nipple and umbilicus mark in terms of the dermatome map?

Answer 19

• Nipple marks T4 segment

- Umbilicus marks T10 segment

Question 20

What areas do C2-C4 innervate?

Answer 20

-posterior scalp, neck and shoulder

Question 21

What spinal nerves innervated upper limb?

Answer 21

C5-T1

Question 22

What spinal nerves innervate lower limb, gluteal region and perineum?

Answer 22

L2-Co1

Question 23

To have complete anaesthesia in dermatome innervation, how many spinal nerves need to be damaged?

Answer 23

At least 3. If only 1 damaged you’ll have reduced sensation. Need 3 because there is overlap of dermatomes

Question 24

What are axial lines in dermatome map on limbs?

Answer 24

Areas of no overlap of dermatomes (goes down middle of each limb)

Question 25

What branch of spinal nerves form nerve plexuses?

Answer 25

Anterior rami

Question 26

What are the spinal nerves forming cervical plexus?

Answer 26

C1-C4

Question 27

What are the spinal nerves forming brachial plexus?

Answer 27

C5-T1

Question 28

What are the spinal nerves forming lumbar plexus?

Answer 28

L1-L4

Question 29

What are the spinal nerves forming sacral plexus?

Answer 29

L5-S4

Question 30

What is the dorsal root ganglion?

Answer 30

It’s the ganglion in the dorsal root where cell bodies of sensory axons synapse

Question 31

What are 3 common typical features of cervical vertebrae?

Answer 31

- Transverse foramen - bifid spinous process - triangular shaped foramen

Question 32

Vertebral arteries pass through C1-C7 transverse foramen. True/false?

Answer 32

False - pass through C1-C6, don’t pass through on C7, accessory veins tend to pass through on C7

Question 33

What 2 features does the atlas (C1) vertebra not have?

Answer 33

- no body - no spinous process - has posterior and anterior arch instead

Question 34

What is the extra feature that the axis (C2) vertebra has?

Answer 34

Odontoid process

Question 35

What is atypical about C7? (2)

Answer 35

- vertebrae prominens (has long spinous process) | - sometimes doesn’t have transverse foramen

Question 36

What are the two parts of the Atlanta-occipital synovial joints?

Answer 36

- occipital condyles | - superior articulate facets

Question 37

What movements occur at the Atlanto-occipital joints?

Answer 37

- flexion and extension of neck | - little lateral flexion and rotation

Question 38

What are the 3 articulations of the Atlanto-axial joint?

Answer 38

- 2 between the inferior articular facets of atlas and superior articular facets of the axis - 1 between the anterior arch of the atlas and odontoid process of the axis

Question 39

What is the main movement of the Atlanto-axial joint?

Answer 39

Rotation

Question 40

How might the spinal cord escape without being damaged in instances of slight dislocation of cervical vertebrae?

Answer 40

Cervical vertebral canal is quite large

Question 41

What is Stage I in cervical vertebral dislocation?

Answer 41

Flexion sprain

Question 42

What is Stage II in cervical vertebral dislocation?

Answer 42

Anterior subluxation, 25% translation

Question 43

What is Stage III in cervical vertebral dislocation?

Answer 43

50% translation

Question 44

What is Stage IV in cervical vertebral dislocation?

Answer 44

Complete dislocation

Question 45

What does sacrum have instead of intervertebral foraminae for spinal nerves to pass through?

Answer 45

anterior and posterior sacral foraminae for anterior and posterior rami

Question 46

What is the sacral hiatus?

Answer 46

Opening at the end of the sacral canal

Question 47

What are the cauda equina made up of?

Answer 47

Nerve roots

Question 48

At what vertebral level does subarachnoid space end?

Answer 48

S2

Question 49

At what vertebral level should spinal and epidural anaesthetic be inserted?

Answer 49

L3/L4

Question 50

Why can you not perform a lumbar puncture in cases of raised ICP?

Answer 50

Because pressure change when removing CSF can cause a herniation in brain

Question 51

What is the order of layers spinal anaesthetic has to pass through from supraspinous ligament inwards?

Answer 51

- supraspinous ligament - interspinous ligament - ligamentum flavum - epidural space - dura mater - arachnoid mater - subarachnoid space

Question 52

What is the name of the clinical condition in which the epidural venous plexus veins are damaged and what can this cause?

Answer 52

- epidural haematoma | - can cause compression of the spinal cord or cauda equina

Question 53

Where is caudal anaesthesia injected into?

Answer 53

Into sacral hiatus

Question 54

What are 2 main uses of laminectomy?

Answer 54

- access spinal cord | - relieve pressure on spinal cord/nerve roots