Where are the two enlargements of the spinal cord?
Inferior to the conus medullaris, the spinal nerves form a bundle called the cauda equina. The spinal cord presents two enlargements at the cervical and lumbar level. In cross section, the gray matter is deep within the spinal cord and is separated into horns.
What is the significance of the cervical and lumbar enlargements?
These enlargements hold the circuitry that control the upper limbs and lower limbs. This is the reason they are enlarged areas of the spinal cord, becuase there is a higher amount of grey matter in these areas than other locations along the cord.
What are the 2 sections of the spine?
The spine is composed of 33 bones, called vertebrae, divided into five sections: the cervical, thoracic, and lumbar spine sections, and the sacrum and coccyx bones. The cervical section of the spine is made up of the top seven vertebrae in the spine, C1 to C7, and is connected to the base of the skull.
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.
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.
What is the role of spinal cord enlargement?
Two regions of the spinal cord are enlarged to accommodate the greater number of nerve cells and connections needed to process information related to the upper and lower limbs (see Figure 1.10B).
What nerves emerge just below the lumbar enlargement?
Summary. Autonomic preganglionic neurons are concentrated in two intermediolateral columns running down the thoracic cord into the first few lumbar segments (sympathetic) and in the segments immediately below the lumbar enlargement (parasympathetic).
Why is there a lumbar enlargement?
The lumbar enlargement of the spinal cord corresponds to the mild increase in cross sectional area of the cord from the T11 level to the conus medullaris. It is enlarged due to the presence of the spinal nerve anterior rami which contribute to the lumbar and sacral plexuses.
What nerves are in the cervical enlargement?
The cervical enlargement of the spinal cord is the source of the spinal nerves that contribute to the brachial plexus and supply the upper limbs.
What part of the spinal cord represents an increase in cell body?
What part of the spinal cord represents an increase in cell body mass for upper limb control? The spinal cord has an obvious enlargement in the cervical region, called the cervical enlargement, where the cell bodies controlling the upper limbs arise.
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.