Anatomy 1: PNS Revision Flashcards
How many pairs of spinal nerves are there?
31
How many spinal nerves are in each section?
8 Cervical C1-C8 12 Thoracic T1-T12 5 Lumbar L1-L5 5 Sacral S1-S5 1 Coccygeal Co1 (not always present)
Nerves are numbered according to the associated vertebrae, does the nerve exit the spine above or below the vertebrae?
C1-C7 above vertebrae
C8 onwards, below
Generally a plexus is formed from anterior or posterior rami?
Anterior
MOTOR axons pass from the __ horn of spinal cord into the __ rootlets then into the __ root then into the spinal nerve
Anterior
SENSORY axons pass from the spinal nerve into the __ root then into the __ rootlets then into the __ horn of the spinal cord
Posterior
What 3 things does a spinal nerve pair supply a body segment with?
General sensory supply to all structures
Somatic motor supply to skeletal muscles
Sympathetic nerve supply to skin and smooth muscle of arterioles
Dermatome map is AKA
Foerster map
T/F there is overlap of skin innervation by adjacent spinal nerves
True
T/F a myotome deep to a dermatome will always be from the same spinal nerve
False
Posterior scalp, neck and shoulder supplied by
C2-C4
Upper limb supplied by
C5-T1
Lower limb, gluteal region + perineum supplied by
L2-Co1
C2-C4 cutaneous supply
Posterior scalp, neck and shoulder
C5-T1 cutaneous supply
Upper limb
L2-Co1 cutaneous supply
Lower limb, gluteal region + perineum
Dermatome landmark: nipple supplied by
T4
Dermatome landmark: bellybutton supplied by
T10
C1-C4 forms the __ plexus
Cervical
Which nerves form the cervical plexus?
C1-C4
C5-T1 forms the __ plexus
Brachial
Which nerves form the brachial plexus?
C5-T1
L1-L4 forms the __ plexus
Lumbar
Which nerves supply the lumbar plexus?
L1-L4
L5-S4 form the __ plexus
Sacral
Which nerves supply the sacral plexus?
L5-S4
Two plexuses spanning from L1-S4 are often referred to as the __ plexus
Lumbosacral
