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 are the cervical and lumbar enlargements?
Two enlargements of the spinal cord can be visualized: The cervical enlargement, which extends between C3 to T1; and the lumbar enlargements which extends between L1 to S2 (Figure 3.1). The cord is segmentally organized. There are 31 segments, defined by 31 pairs of nerves exiting the cord.
What is the spinal cord enlargement?
The lumbar enlargement (or lumbosacral enlargement) is a widened area of the spinal cord that gives attachment to the nerves which supply the lower limbs. It commences about the level of T11 and ends at L2, and reaches its maximum circumference, of about 33 mm.
What does the cervical enlargement innervate?
The cervical enlargement is the site of the cell bodies of the motor neurons that innervate the upper limbs, as well as the site where the sensory nerves from the upper limbs synapse.
What causes cervical enlargement of the spinal cord?
The reason behind the enlargement of the cervical region is because of the increased neural input and output to the upper limbs. An analogous region in the lower limbs occurs at the lumbar enlargement.
What could happen if there is damage to C1 C5?
Breathing Difficulties
Without immediate medical attention, C1 spinal cord injuries are typically fatal. The C3-C5 spinal nerves innervate the diaphragm, and because messages from the brain may not be able to get past the C1 level, individuals may not be able to breathe.
Is Spinal stenosis a degenerative disease?
Lumbar spinal stenosis is a narrowing of the spinal canal, compressing the nerves traveling through the lower back into the legs. While it may affect younger patients, due to developmental causes, it is more often a degenerative condition that affects people who are typically age 60 and older.
What is the function of lumbar enlargement?
Description. The lumbar enlargement gives attachment to the nerves which supply the lower limbs. It commences about the level of the ninth thoracic vertebra, and reaches its maximum circumference, of about 33 mm, opposite the last thoracic vertebra, below which it tapers rapidly into the conus medullaris.
What is lumbar enlargement area?
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.
How many discs are in the cervical spine?
There are 6 intervertebral discs in the highly-mobile cervical spine. These cervical discs tend to be thinner than the lumbar discs in the lower back but thicker than the thoracic discs in the less-mobile upper back.
Why are there 8 cervical nerves?
These complex networks of nerves enable the brain to receive sensory inputs from the skin and to send motor controls for muscle movements. In the cervical spine, there are eight pairs of spinal nerves labeled C1 to C8, which innervate the neck, shoulder, arm, hand, and more.
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 are the cervical spinal nerves?
Nerves in the cervical spine
Cervical nerves C1, C2 and C3 control your forward, backward and side head and neck movements. The C2 nerve provides sensation to the upper area of your head; C3 gives sensation to the side of your face and back of your head.
