Question
| A. | T8 |
| B. |
T9 |
| C. |
T10 |
| D. |
T11 |
|
Correct Answer � C Explanation |
 |
Important dermatome & anatomical landmarks
Following is a list of spinal nerves and points that are characteristically belonging to the dermatome of each nerve.
* C2 – At least one cm lateral to the occipital protuberance at the base of the skull. Alternately, a point at least 3 cm behind the ear.
* C3 – In the supraclavicular fossa, at the midclavicular line.
* C4 – Over the acromioclavicular joint.
* C5 – On the lateral (radial) side of the antecubital fossa, just proximally to the elbow.
* C6 – On the dorsal surface of the proximal phalanx of the thumb.
* C7 – On the dorsal surface of the proximal phalanx of the middle finger.
* C8 – On the dorsal surface of the proximal phalanx of the little finger.
* T1 – On the medial (ulnar) side of the antecubital fossa, just proximally to the medial epicondyle of the humerus.
* T2 – At the apex of the axilla.
* T3 – Intersection of the midclavicular line and the third intercostal space
* T4 – Intersection of the midclavicular line and the fourth intercostal space, located at the level of the nipples.
* T5 – Intersection of the midclavicular line and the fifth intercostal space, horizontally located midway between the level of the nipples and the level of the xiphoid process.
* T6 – Intersection of the midclavicular line and the horizontal level of the xiphoid process.
* T7 – Intersection of the midclavicular line and the horizontal level at one quarter the distance between the level of the xiphoid process and the level of the umbilicus.
* T8 – Intersection of the midclavicular line and the horizontal level at one half the distance between the level of the xiphoid process and the level of the umbilicus.
* T9 – Intersection of the midclavicular line and the horizontal level at three-quarters of the distance between the level of the xiphoid process and the level of the umbilicus.
* T10 – Intersection of the midclavicular line, at the horizontal level of the umbilicus.
* T11 – Intersection of the midclavicular line, at the horizontal level midway between the level of the umbilicus and the inguinal ligament.
* T12 – Intersection of the midclavicular line and the midpoint of the inguinal ligament.
* L1 – Midway between the key sensory points for T12 and L2.
* L2 – On the anterior medial thigh, at the midpoint of a line connecting the midpoint of the inguinal ligament and the medial epicondyle of the femur.
* L3 – At the medial epicondyle of the femur.
* L4 – Over the medial malleolus.
* L5 – On the dorsum of the foot at the third metatarsophalangeal joint.
* S1 – On the lateral aspect of the calcaneus.
* S2 – At the midpoint of the popliteal fossa.
* S3 – Over the tuberosity of the ischium or infragluteal fold
* S4 and S5 – In the perianal area, less than one cm lateral to the mucocutaneous zone
