Spinal Nerves (Sensory)

Question 1

Briefly, what does a spinal nerve pair supply?

Answer 1

Everything in one segment of the body

Question 2

Where does somatic sensory supply from a spinal nerve pair act?

Answer 2

On sensation specific receptors in all body wall structures

Question 3

Where do each of the following motor modalities from a spinal nerve synapse a) somatic motor? b) sympathetic?

Answer 3

a) All body wall skeletal muscle fibres b) All body wall glands and smooth muscle fibres

Question 4

Describe a spinal reflex?

Answer 4

Spinal cord segmental synapses between somatic sensory and motor axons

Question 5

Name the 3 areas of the CNS where somatosensory pathology can originate from?

Answer 5

Ascending spinal cord tracts (DCML/spinothalamic), internal capsule or primary somatosensory cortex

Question 6

Dermatomal testing allows you to assess the integrity of what structures? Are these structures sensory or motor or both?

Answer 6

Dorsal rootlets (sensory), dorsal root (sensory), spinal nerve (sensory and motor)

Question 7

Describe where each of the following dermatomes supplies: a) C2? b) C3? c) C4?

Answer 7

C2 = back of scalp and adam’s apple / C3 = back of neck and jugular notch / C4 = clavicle and shoulder tip

Question 8

Describe where each of the following dermatomes supplies: a) C5? b) C6? c) C7? d) C8?

Answer 8

C5 = badge patch / C6 = thumb / C7 = middle finger / C8 = little finger

Question 9

Describe where each of the following dermatomes supplies: a) T1? b) T2?

Answer 9

T1 = medial forearm / T2 = medial arm and sternal angle

Question 10

Describe where each of the following dermatomes supplies: a) T4? b) T10? c) T12?

Answer 10

T4 = male nipple / T10 = umbilicus / T12 = pubic symphysis

Question 11

Describe where each of the following dermatomes supplies: a) L1? b) L2? c) L3? d) L4? e) L5?

Answer 11

L1 = groin (hands in pockets) / L2 = anterior thigh / L3 = anterior knee / L4 = medial malleolus / L5 = dorsum of foot

Question 12

Describe where each of the following dermatomes supplies: a) S1? b) S2? c) S3? d) S4? e) S5?

Answer 12

S1 = heel / S2 = posterior knee / S3 = buttock / S4 = perineum / S5 = perianal skin

Question 13

What does the sensory component of the posterior rami supply?

Answer 13

A strip of skin down the centre of the posterior neck and back

Question 14

The area of the back which is supplied by the T2 posterior rami is found just above which structure? The area of the back which is supplied by the L3 posterior rami is found just above which structure?

Answer 14

Spine of the scapulae / Iliac crests

Question 15

Anterior rami combine to form what? Which are the only anterior rami for which this is not the case?

Answer 15

Plexuses / T2-T12

Question 16

What nerves are responsible for sensory supply to the upper anterolateral trunk wall?

Answer 16

Intercostal nerves

Question 17

What forms intercostal nerves?

Answer 17

Anterior rami of T2-T11

Question 18

What nerves are responsible for sensory supply to the lower anterolateral trunk wall?

Answer 18

Ilioinguinal and iliohypogastric nerves

Question 19

What forms the ilioinguinal and iliohypogastric nerves?

Answer 19

The bifurcation of the anterior ramus of L1 spinal nerve

Question 20

What nerve is responsible for supplying the T12 dermatome of the anterolateral trunk wall?

Answer 20

Subcostal nerve

Question 21

What forms the subcostal nerve?

Answer 21

T12 anterior ramus

Question 22

What is the main difference between a spinal nerve and a named nerve?

Answer 22

Spinal nerves contain axons originating from only one spinal cord level. Named nerves contain axons originating from one or more spinal cord levels supplying a particular area.

Question 23

Describe briefly the cutaneous innervation of the neck a) posteriorly? b) anteriorly?

Answer 23

a) posterior rami of C2-C8 b) cervical plexus formed of anterior rami C1-C4

Question 24

Where does the lesser occipital nerve (C2) supply?

Answer 24

The skin posterior to the ear

Question 25

Where does the great auricular nerve (C2, C3) supply?

Answer 25

The skin over the angle of the mandible and some of the external ear

Question 26

Where does the transverse cervical nerve (C2, C3) supply?

Answer 26

The skin over the anterior neck

Question 27

Where do the supraclavicular nerves (C3, C4) supply?

Answer 27

The skin over the clavicles and shoulder tips

Question 28

What NERVES (not roots) make up the cervical plexus?

Answer 28

Lesser occipital nerves, great auricular nerve, transverse cervical nerve, supraclavicular nerves

Question 29

What nerve and nerve roots are responsible for referred pain from the diaphragm?

Answer 29

Supraclavicular nerves (C3, 4)

Question 30

What is the nerve point of the neck?

Answer 30

The area where all of the sensory nerves of the cervical plexus converge and pass from superficial to deep fascia

Question 31

Where is the nerve point of the neck found?

Answer 31

The midpoint of the posterior border of SCM

Question 32

Which nerve roots are responsible for referred pain from the myocardium?

Answer 32

T1 and T2 anterior rami

Question 33

The anatomical snuffbox is supplied by cutaneous branches of which nerve?

Answer 33

Radial nerve