Sacral Spinal Nerves Flashcards
How many pairs of sacral spinal nerves?
Five pairs
The sacral spinal nerves descend inside the dura to form what?
cauda equina
Each sacral nerve divides into what?
Anterior primary ramus
Posterior primary ramus
Where does the sacral nerve division occur?
Inside the sacrum
The posterior primary rami of S1-S4 travel through what?
The four posterior sacral foramina
The S5 posterior primary rami travels through what?
Sacral hiatus
The sacral posterior primary ram decrease in size from ____ to ______.
Superior to inferior
S1 largest, S5 smallest
The posterior primary rami of _____ divide into ____ and ____.
S1-S3
Medial and lateral
The medial branch of S1-S3 posterior primary rami supply what?
Adjacent multifidi
The lateral branch of S1-S3 posterior primary rami combine with what? To supply what?
L5 and S4
Skin over the buttocks
Which branch of the posterior primary rami is motor?
medial
Which branch of the posterior primary rami is sensory?
lateral
What happens to the posterior primary rami of S4 and S5? (They don’t divide)
They unite with the coccygeal posterior rami
When the posterior primary rami of S4 and S5 unite with the coccygeal plexus, the supply what?
Skin over the coccyx
The anterior primary rami of S1-S4 travel through what?
Four anterior sacral foramina
