Anatomy Flashcards
What 5 nerves comprise the superficial cervical plexus?
Lesser occipital Greater occipital Greater auricular Transverse cervical Supraclavicular
Where can the superficial cervical plexus be blocked?
The midpoint of the posterior border of the SCM
What nerve is often blocked along with the superficial cervical plexus? How would you know?
Accessory nerve Paralysis of the ipsilateral trapezius
What spinal levels give rise to the cervical plexus?
C1-C4
What nerve provides sensation to the airway below the level of the vocal cords? Where can it be anesthetized?
recurrent laryngeal nerve
through the cricothyroid membrane
What nerve provides sensation to the airway from the vocal cords to the inferior aspect of the epiglottis? Where can it be anesthetized?
superior laryngeal nerve, internal branch
through the thyrohyoid membrane
What nerve provides sensation to the airway from the superior aspect of the epiglottis to the base of the tongue? Where can it be anesthetized?
glossopharyngeal nerve
at the base of the posterior tonsillar pillars
What can complicate a block of the glossopharyngeal nerve? Why?
sinus bradycardia -> asystole
the glossopharyngeal nerve provides afferent signals from the carotid baroreceptors
What innervates all but one of the airway muscles?
Recurrent laryngeal nerve
What is the only airway muscle not innervated by the recurrent laryngeal nerve? What is it innervated by? What does it do?
- cricothyroid muscle
- external branch of the superior laryngeal nerve
- tenses vocal cords
What forms the stellate ganglion?
Fusion of the lowest cervical and first thoracic ganglia
What anatomic landmark helps to identify C6?
Cricoid cartilage
Where is a stellate ganglion block performed? Why?
Medial to the carotid pulse at C6 Avoid intravascular injection into the vertebral artery which is protected by the transverse process at C6
What indicates a successful stellate ganglion block?
Horner’s syndrome (ptosis, miosis, anhidrosis) Increase in arm temperature (increased blood flow)
What is Chassaignac’s tubercle?
Anterior tubercle of the C6 vertebra, separating the carotid and vertebral arteries
What anatomic landmark is associated with C7?
Vertebra prominens
What are the borders of the epidural space?
anterior: posterior longitudinal ligament lateral: pedicles and intervertebral foraminae posterior: ligamentum flavum rostral: foramen magnum caudal: sacral hiatus
What anatomic landmark helps to identify T3?
Scapular spines
What anatomic landmark helps to identify T12?
The lowest rib
What anatomic landmark helps to identify S2?
Posterior superior iliac spine
What nerve is most commonly missed by an axillary nerve block? How would you test for it?
Musculocutaneous Test sensation along the lateral aspect of the forearm
What nerve is most commonly missed by an interscalene block?
Ulnar nerve and 2nd intercostal brachial
Where are the branching nerves of the brachial plexus located relative to the axillary artery?
Median nerve: superior Ulnar nerve: inferior Radial nerve: posterior and somewhat lateral
What nerve may be compromised during brachial arterial line placement at the elbow?
Median nerve lying medial to the artery
What nerve is comprised of anterior divisions of the lumbar plexus?
Obturator nerve
What nerves are comprised of posterior divisions of the lumbar plexus?
Femoral nerve and lateral femoral cutaneous nerve
What two nerves are given off by the sacral plexus?
Sciatic nerve and posterior cutaneous nerve of the thigh
What are the borders of the popliteal fossa?
Upper border: semitendinosis and semimembranosis (medial), biceps femoris (lateral) Lower border: gastrocnemius
Which vessel can cause trigeminal neuralgia by compressing the trigeminal nerve?
Superior cerebellar artery
Which nerve causes laryngospasm by involuntary adduction of the vocal cords?
Superior laryngeal nerve
Between which spinal levels does the artery of Adamkiewicz (great radicular artery) arise in 75% of people?
T9-T12
Which maneuver is most important for overcoming airway obstruction?
Head extension
