Efferent motor axons bring motor information from the brain to the body; they travel through the ventral roots of the spinal cord. All spinal nerves—except the first pair—emerge from the spinal column through an opening between vertebrae, called an intervertebral foramen.
Where do the spinal nerves exit?
The nerve roots exit the spinal canal through the intervertebral foramen, small hollows between each vertebra. The brain and the spinal cord make up the Central Nervous System (CNS). The nerve roots that exit the spinal cord/spinal canal branch out into the body to form the Peripheral Nervous System (PNS).
Do spinal nerves exit above or below vertebrae?
All spinal nerves, except the first, exit below their corresponding vertebrae. In the cervical segments, there are 7 cervical vertebrae and 8 cervical nerves (Figure 3.2). C1-C7 nerves exit above their vertebrae whereas the C8 nerve exits below the C7 vertebra.
Where do spinal nerves originate and end?
The spinal cord is an extension of the central nervous system (CNS), which consists of the brain and spinal cord. The spinal cord begins at the bottom of the brain stem (at the area called the medulla oblongata) and ends in the lower back, as it tapers to form a cone called the conus medullaris.
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.
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.
What is the number of spinal nerves?
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.
What happens if the posterior root of a spinal nerve is severed?
D) cell bodies of sensory neurons. E) interneurons. If the posterior root of a spinal nerve is severed, A) output to skeletal muscles would be blocked.
What are the 4 major nerve plexuses?
Of the four major nerve plexuses (cervical, brachial, lumbar, and sacral), only the brachial plexus and sacral plexus can be assessed satisfactorily in the EDX laboratory.
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.