The cervical and lumbar regions of the spinal cord show a larger diameter compared to the rest of the regions. The cervical enlargement and lumbar enlargement represent an increased amount of neurons in the gray matter and axons in the white matter that serve the upper limbs and lower limbs, respectively.
Which areas of the spinal cord contain enlargements that represent an increase in cell body mass?
According to its rostrocaudal location the spinal cord can be divided into four parts: cervical, thoracic, lumbar and sacral, two of these are marked by an upper (cervical) and a lower (lumbar) enlargement.
What part of the spinal cord represents an increase?
The different cord regions can be visually distinguished from one another. 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.
Which part of spinal cord is mainly composed of cell body?
The dorsal root ganglia contain the cell bodies of sensory neurons. Axons of these sensory neurons travel into the spinal cord via the dorsal roots. The grey matter in the center of the cord contains interneurons and the cell bodies of motor neurons, axons, and dendrites.
Why is the cervical and lumbar regions enlarged?
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 is the connection between the brain and the spinal cord?
The part of the skull where the brain sits is called the cranium. The base, or lower part, of the brain is connected to the spinal cord. Together, the brain and spinal cord are known as the central nervous system (CNS). Many nerves send electrical signals to and from the brain and spinal cord.
What is the inner portion of the spinal cord?
The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column. It encloses the central canal of the spinal cord, which contains cerebrospinal fluid.
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 gray commissure of the spinal cord?
a bundle of nerve fibers that surrounds the central canal of the spinal cord and connects the anterior and dorsal horns of gray matter in each half of the cord.
What are the 3 main parts of the spinal cord?
The spine has three normal curves: cervical, thoracic and lumbar. There are seven cervical vertebrae in the neck, 12 thoracic vertebrae in the torso and five lumbar vertebrae in the lower back.
Where is your spinal cord?
Anatomically, the spinal cord runs from the top of the highest neck bone (the C1 vertebra) to approximately the level of the L1 vertebra, which is the highest bone of the lower back and is found just below the rib cage.
What is the function of cell body?
Cell body. Also known as a soma, the cell body is the neuron’s core. The cell body carries genetic information, maintains the neuron’s structure, and provides energy to drive activities. Like other cell bodies, a neuron’s soma contains a nucleus and specialized organelles.
What is the function of the lumbar enlargement?
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.
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.
Which is the widest part of the spinal cord?
It is a long tube about 18 inches (45 cm) in length and around half an inch (1 cm) in diameter at its widest point. At its inferior end, the spinal cord tapers to a point known as the conus medullaris and gives rise to many large nerve fibers known as the cauda equina.