The Back Nerves and Vessels

Question 1

Where does the spinal cord lie?

Answer 1

Lies in vertebral canal (not intervertebral canal)

Question 2

Where does the spinal cord end?

Answer 2

Ends as conus medullaris at L1 (adult); L3 (child)

Question 3

What forms the cauda equina?

Answer 3

Lumbar, sacral nerves and the coccygeal nerve

Question 4

Where does the pia extend and attach to?

Answer 4

coccyx as filum terminale

Question 5

What is between the Arachnoid and the pia

Answer 5

subarachnoid space, filled with CSF

Question 6

Where is the lumbar puncture?

Answer 6

Lumbar puncture at L3/4 or L4/5.

Question 7

Where do the Dural and arachnoid extend to?

Answer 7

S3 vertebra = dural sac

The dural sac is the membranous sheath of dura mater that surrounds the spinal cord and the cauda equina. Contains CSF.

Question 8

What are Cervical and Lumbar enlargements for?

Answer 8

(for brachial and lumbar, plexus nerves, resp.)

Question 9

What does the lateral horn contain?

Answer 9

Cell bodies of the sympathetic neurons.

Question 10

Where is the lateral horn present?

Answer 10

Between levels T1-L2/3 vertebrae (thoracolumbar/sympathetic outflow), and between levels S2-S4 vertebrae (sacral/parasympathetic outflow).

Question 11

Do sympathetic nerves synapse before reaching the muscle/ tissue?

Answer 11

Yes

Question 12

Is the grey ramus myelinated?

Answer 12

No

Question 13

Is the white ramus myelinated?

Answer 13

Yes

Question 14

What is the position of the paravertebral (sympathetic trunk) ganglia?

Answer 14

Lie parallel to the spinal cord

Question 15

What is the travel of the sympathetic nerve impulses?

Answer 15

They emerge in the ventral root via a white ramus (preganglionic fibres). After synapsing in the sympathetic chain ganglion, they re-enter the spinal nerve via a grey ramus and are distributed in both dorsal and ventral rami of the spinal nerve (postganglionic fibres).

Question 16

Where do post ganglionic sympathetic nerve impulses travel to?

Answer 16

Skin and body wall structures such as arrector pili muscles, blood vessels and glands

Question 17

How do parts of the body above and below T1-L2/3 receive sympathetic innervation?

Answer 17

The sympathetic chain - A paired set of paravertebral ganglia stretching from C1 o the end of the coccyx.

Question 18

What are the three options of travel for the sympathetic fibres leaving the spinal cord?

Answer 18

They can synapse at the level of entry.

They can run up or down the chain and synapse.

They can pass straight through and synapse in a prevertebral/preaortic ganglion.

Question 19

Where do sympathetic preganglionic fibres to the thoracic viscera (heart and lungs) synapse?

Answer 19

Synapse IN the chain, then go to the cardiopulmonary plexus, and then on to the heart and lungs.

Question 20

Where do sympathetic preganglionic fibres to the abdominal viscera (heart and lungs) synapse?

Answer 20

They pass THROUGH the chain with out synapsing there and synapse instead on prevertebral/preaortic ganglia in the abdomen and then on to the abdominal viscera.

Question 21

Where are prevertebral / preaortic ganglia located?

Answer 21

Anterior to abdominal aorta, in plexuses surrounding its major branches

Question 22

What are splanchnic nerves?

Answer 22

They are sympathetic nerves which:

• Do not re-enter the spinal nerve
• Supply only the viscera

Question 23

Where do the thoracic splanchnic nerves come from? And where do they synapse?

Answer 23

Come from T1-T4

They synapse in the sympathetic chain before they run to the organ concerned (contained within the thoracic viscera).

Question 24

Where do the abdominal splanchnic nerves come from? And where do they synapse?

Answer 24

They come from T5-T12 and L1-L2(3)

They synapse outwith the chain in preaortic or prevertebral ganglia and then run to the organ concerned (in the abdominal viscera)

Question 25

What do the splanchnic nerves T5-T12 have to pass through in order to reach the abdominal organs?

Answer 25

The diaphram

Question 26

Where does general sensory information from organs run?

Answer 26

With parasympathetic fibres

Question 27

Where do pain impulses normally run?

Answer 27

Normally run with the sympathetic fibres, (in the pelvis also with parasympathetic fibres)

Question 28

What is the travel of the sensory afferents from both the sympathetic fibres and the parasympathetic fibres?

Answer 28

Both enter the dorsal root and synapse in the dorsal root ganglion before entering the lateral horn and travelling up the spinal cord to the brain.

Question 29

Where do parasympathetic nerve fibres arise from?

Answer 29

S2, S3 and S4 spinal nerves

From the 3rd, 7th, 9th and 10th cranial nerves

Question 30

What name is given to the S2, S3 and S4 nerves?

Answer 30

The pelvic splanchnic nerves- they supply the pelvic organs

Question 31

Where do the pelvic splanchnic nerve cell bodies reside?

Answer 31

In the lateral horn of the spinal cord at the T12-L2(3) vertebral levels

Question 32

Where do the bilateral preganglionic parasympathetic nerve axons runing through the lumbosacral plexus travel to?

Answer 32

The sacral foramina

Question 33

Where do the preganglionic parasympathetic nerve axons exit the vertebral column?

Answer 33

They exit the vertebral column in the cauda equina as S2- S4 spinal nerves.

Question 34

What is the pelvic/inferior hypogastric plexus?

Answer 34

A mixed sympathetic and parsympathetic distributing network.

After the parasympathetic axons have left the vertebral canal they run through here to synapse at a parasympathetic ganglion close to or within the target organ.

Question 35

What is the sentinal lymph node?

Answer 35

The hypothetical first lymph node or group of nodes draining a cancer.

Question 36

Where are the Axillary lymph nodes?

Answer 36

They lie along the walls of the the axilla in close association with the auxillary vessels

Question 37

What are the names of the auxilary lymph nodes?

Answer 37

apical, central, lateral, anterior and posterior nodes

Question 38

What is significant about the auxilliary lymph nodes?

Answer 38

They have particular significance in the spread of breast cancer

Question 39

Label the lymph nodes A-E

Answer 39