Exam 3: Thoracic Spinal Nerves Flashcards
How many nerve pairs are in the thoracic spinal nerves
12 pairs of thoracic nerve roots
Which division (ant or post primary ramus) divides into a medial and lateral branch
Posterior primary ramus
What muscles are supplies by the medial branches of the posterior primary ramus
Semispinalis (upper 6), longissimus (lower 6), multifidi
What sensory supply is from the medial branch of the posterior primary ramus
Sensory supplies skin paraspinally
What branches increase in size from superior to inferior
Lateral branches of posterior primary ramus
What muscles are supplied by lateral branches of the posterior primary ramus
Longissimus, iliocostalis, levator costarum
Where do the lateral branches of the posterior primary rami provide sensory info to
Sensory supply to skin near costal angles
What course do the anterior primary rami follow
Course of the rib above the nerve
The anterior primary ramus of T 1 contributes to what
The brachial plexus, small branch forms the first intercostal nerve
What nerve is contributed to from the anterior primary rami of T2 and T1 sometimes
Intercosotobrachial nerve
Each intercostal nerve gives off what that divides into anterior and posterior branches and what does it supply
Lateral cutaneous branch supplies the overlying skin (back to costal angle)
Where do intercostal nerves terminate and what do they supply
They terminate as anterior cutaneous branches that supply skin close to the midline
Intercostal nerves course along their adjacent ribs giving off muscular branches to supply what?
Internal, external, innermost intercostals/ serratus post/ transversus thoracis and others 7-11
Intercostal nerves 7-11 course along adjacent ribs to supply what specifically along with the other muscles of intercostal nerves
Transverse abdominal, internal abdominal oblique, external abdominal oblique, rectus abdominus (TIRE)
Besides musculature what else do intercostal nerves supply
Adjacent blood vessels, bones, joints, and ligaments
What nerve is the largest of the thoracic nerves and where is it from?
Subcostal nerve from T12
What else does the subcostal nerve contribute to besides normal intercostal nerve innervations
Contributes to lumbar plexus and can supply skin as far inferior as the superior buttocks
What is another name for the subcostal nerve supplying skin to superior buttocks
Cluneal nerves
Each thoracic nerve communicates with _____ by way of both _____ and ____ communicans
Sympathetic trunk/white/gray
What is the difference in location between gray and white communicans
Gray ramus is medial and at all 12 levels (postgang symp nonmyelinated), white ramus is more lateral and only located at T1-L2 (pregang symp. Myelinated fibers)
