The spinal nerves that originate from the thoracic portion of the spinal cord don't form plexuses. The word thoracic pertains to the thorax.
The cervical spinal nerves form the cervical plexus, the brachial spinal nerves form the brachial plexus, the lumbar and sacral spinal nerves form the lumbosacral plexus, and the sacral spinal nerves form the sacral plexus.
The spinal nerve is not a nerve plexus. Nerve plexuses are complex interwoven networks of nerves that form in the peripheral nervous system, whereas spinal nerves are the mixed nerves that emerge from the spinal cord and are not organized in a plexus-like fashion.
No, the dorsal ramus does not form a plexus. It supplies nerves to the skin and muscles of the back in a segmental pattern without intermingling as in a plexus, which is a network of nerves where fibers from different spinal nerves combine and then redistribute.
The brachial plexus is formed by the spinal nerves C5-T1, while the lumbosacral plexus is formed by the spinal nerves L1-S4. These plexuses are networks of nerves that supply motor and sensory innervation to the upper and lower limbs, respectively.
The brachial plexus contains fibers from the ventral rami of the cervical spinal nerves (C5-C8) and the first thoracic spinal nerve (T1). These fibers combine to form the nerves that innervate the upper limb.
The phrenic nerve does not arise from the branchial plexus. It originates from the cervical spinal nerves C3-C5.
The brachial plexus is the spinal cord feature associated with the leash of nerves supplying the upper limbs.
The brachial plexus primarily comprises the ventral rami of spinal nerves C5 to T1, but there are several nerves that are not part of it. Notably, the intercostal nerves, which arise from the thoracic spinal nerves (T1 to T11), and the phrenic nerve, which originates from C3 to C5, are not included in the brachial plexus. Additionally, the cranial nerves, such as the vagus nerve (cranial nerve X), also do not belong to this plexus.
The nerves that innervate the colon originate from the spinal levels T10-L2. These nerves form the superior mesenteric plexus, which supplies the colon with autonomic innervation.
The phrenic nerve is not a part of the brachial plexus. It originates from the cervical spinal nerves (C3-C5) and is primarily responsible for innervating the diaphragm, facilitating respiration. In contrast, the brachial plexus is a network of nerves that supplies the upper limb, formed from the anterior rami of spinal nerves C5 to T1.
Spinal nerves exiting the spinal canal between L4 and S4 collectively make up the sacral plexus.
It provides innervation to the pelvis, its organs and the lower limb