Passes caudally on the deep surface of the rectus abdominis m.
Cranial superficial epigastric a
Supplies skin over the rectus abdominis m.
Supplies the caudal thoracic and cranial abdominal mammary glands
Thoracic spinal nn. (emerge from intervertebral foramen)
Intercostal nn. (ventral branches of the first 12 thoracic spinal nerves)
Lateral cutaneous branches
Ventral cutaneous branches
Lateral thoracic n.
Emerges from the axilla between the latissimus dorsi and deep pectoral mm. to terminate on the ventral border of the cutaneous trunci m.
GSE to the cutaneous trunci m.
Phrenic nn. (paired)
Arise from ventral branches of the 5th, 6th, and sometimes 7thcranial nerves
The phrenic nerves contain motor, sensory, and sympathetic nerve fibers
Provide the only GSE to the diaphragm as well as GSA to the central tendon
Left phrenic n.
Within the caudal mediastinum
Right phrenic n.
NOT within the caudal mediastinum b/c within the plica vena cava
Sympathetic trunk (paired)
Strand of nerve fibers from the sympathetic division of the ANS
Sympathetic chain ganglion
Contain cell bodies of postganglionic sympathetic neurons
Usually located in the sympathetic trunk at the point where each rami communicans joins it
Nerve fiber branches that join (communicate) spinal nerves and sympathetic trunk ganglia
Each preganglionic sympathetic axon must pass through here to reach the sympathetic trunk, though not all synapse within chain ganglia (splanchnic nn., head nn. that synapse at cranial cervical ganglion)
Rami communicans of spinal cord segments T1-L5 contain both preganglionic and postganglionic axons
Sympathetic ganglia of cranial mediastinum
Cervicothoracic ganglion (paired)
Formed from fusion of caudal cervical ganglion and first 2-3 thoracic ganglia
Rami communicans leave this ganglion and connect to the ventral branches of spinal nerves C7, C8, T1 and T2, which help form the brachial plexus, a pathway for postganglionic axons to reach the thoracic limb
Branch that follows the vertebral a. through the cervical vertebra transverse foramina
Middle cervical ganglion (paired)
Junction of the ansa subclavian and vagosympathetic trunk
Branches from the ansa subclavian and middle cervical ganglion go to the heart
Both sympathetic (pre- and postganglionic) and parasympathetic (preganglionic) fibers