Human Anatomy and Physiology : Help with Evaluation Methods for the Nervous System

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #1415 : Human Anatomy And Physiology

At which vertebrae would you enter to remove cerebrospinal fluid (CSF) from the back?

Possible Answers:

T3/T4

L4/L5

Posterior sacral foramina

L2

Correct answer:

L4/L5

Explanation:

When performing a spinal tap you enter the intervertebral space at the L3/L4 or L4/L5 level. This is because the spinal cord ends around L1/L2. Nerves continue past this point as part of the cauda equina, however they are not in danger of being pierced as they move out of the way of the needle. The needle will pass through various layers until the subarachnoid space where CSF is located.

Example Question #1417 : Human Anatomy And Physiology

At what level does one perform a lumbar puncture?

Possible Answers:

L1/L2 or L2/L3

Only L1/L2

L4/L5 or L3/L4

Only L3/L4

Correct answer:

L4/L5 or L3/L4

Explanation:

In human adults the spinal cord (caudal tip) usually ends at the level of L1/L2. Thus lumbar punctures are performed between the L3 and L4 vertebrae or between L4 and L5, so there is no risk of damage to the spinal cord. 

Example Question #41 : Injuries And Disorders

You suspect that a patient may have an injury to her dorsal scapular nerve. What abnormal movement pattern would make you suspect this?

Possible Answers:

Excess scapular upward rotation

Excess scapular internal rotation ("winging")

Excess scapular elevation

Excess scapular downward rotation

Correct answer:

Excess scapular upward rotation

Explanation:

Although electrodiagnostic testing would be needed to definitively diagnose a dorsal scapular nerve pathology, excess scapular upward rotation could suggest dysfunction of this nerve. Because the dorsal scapular nerve innervates the rhomboid major and minor, which are downward scapular rotators (as well as scapular elevators, and adductors) injury to this nerve would decrease eccentric control of upward rotation, causing excessive movement in that direction. Excess scapular internal rotation is associated with injury to the long thoracic nerve, not the dorsal scapular nerve.

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