How are spinal nerves formed?
The spinal nerves are relatively large nerves that are formed by the merging of a sensory nerve root and a motor nerve root. These nerve roots emerge directly from the spinal cord—sensory nerve roots from the back of the spinal cord and the motor nerve roots from the front of the spinal cord.
What part of the spine controls the heart?
Thoracic (mid back) – the main function of the thoracic spine is to hold the rib cage and protect the heart and lungs. The twelve thoracic vertebrae are numbered T1 to T12.
What part of the spine has no nerves?
Because the lumbar spine has no spinal cord and has a large amount of space for the nerve roots, even serious conditions—such as a large disc herniation—do not typically cause paraplegia (loss of motor function in the legs).
Which spinal nerves affect which parts of the body?
The nerves of the cervical spine go to the upper chest and arms. The nerves in your thoracic spine go to your chest and abdomen. The nerves of the lumbar spine then reach to your legs, bowel, and bladder. These nerves coordinate and control all the body’s organs and parts, and let you control your muscles.
Are all cranial nerves mixed?
Five cranial nerves have mixed sensory, motor and parasympathetic function. These five will be discussed in detail here. The mixed cranial nerves are CN III Occulomotor, CN V Trigeminal, CN VII Facial, CN IX Glossopharyngeal and CN X Vagus.
How are spinal cord segments named?
The numbers refer to the spinal segments by which each nerve is named C = cervical; T = thoracic; L = lumbar; S = sacral spinal cord segments (dermatome).
How many pairs of spinal nerves do humans have?
In total, there are 31 pairs of spinal nerves, grouped regionally by spinal region. More specifically, there are eight cervical nerve pairs (C1-C8), twelve thoracic nerve pairs (T1-T12), five lumbar nerve pairs (L1-L5), and a single coccygeal nerve pair.