Conus Medularis
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Conus Medularis
The conus medullaris (Latin for "medullary cone") or conus terminalis is the tapered, lower end of the spinal cord. It occurs near lumbar vertebral levels 1 (L1) and 2 (L2), occasionally lower. The upper end of the conus medullaris is usually not well defined, however, its corresponding spinal cord segments are usually S1–S5. After the spinal cord tapers out, the spinal nerves continue to branch out diagonally, forming the cauda equina. The pia mater that surrounds the spinal cord, however, projects directly downward, forming a slender filament called the filum terminale, which connects the conus medullaris to the back of the coccyx. The filum terminale provides a connection between the conus medullaris and the coccyx which stabilizes the entire spinal cord. Blood supply The blood supply consists of three spinal arterial vessels—the anterior median longitudinal arterial trunk and the right and left posterior spinal arteries. Other less prominent sources of blood supply in ...
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Cauda Equina
The cauda equina () is a bundle of spinal nerves and spinal nerve rootlets, consisting of the second through fifth lumbar nerve pairs, the first through fifth sacral nerve pairs, and the coccygeal nerve, all of which arise from the lumbar enlargement and the conus medullaris of the spinal cord. The cauda equina occupies the lumbar cistern, a subarachnoid space inferior to the conus medullaris. The nerves that compose the cauda equina innervate the pelvic organs and lower limbs to include motor innervation of the hips, knees, ankles, feet, internal anal sphincter and external anal sphincter. In addition, the cauda equina extends to sensory innervation of the perineum and, partially, parasympathetic innervation of the bladder. Structure In adulthood, the cauda equina is made of lumbosacral spinal nerve roots. Development In humans, the spinal cord stops growing in infancy. At birth the end of the spinal cord is about the level of the third lumbar vertebra, or L3. ...
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Posterior Spinal Arteries
The posterior spinal artery (dorsal spinal arteries) arises from the vertebral artery in 25% of humans or the posterior inferior cerebellar artery in 75% of humans, adjacent to the medulla oblongata. It is usually double, and spans the length of the spinal cord. It supplies the grey and white posterior columns of the spinal cord. Structure The posterior spinal artery arises above the foramen magnum. It passes posteriorly to descend the medulla passing through and behind of the posterior roots of the spinal nerves. Along its course it is reinforced by a succession of segmental or radiculopial branches, which enter the vertebral canal through the intervertebral foramina, forming a plexus called the vasocorona with the anterior vertebral arteries. Below the medulla spinalis and upper cervical spine, the posterior spinal arteries are rather discontinuous; unlike the anterior spinal artery, which can be traced as a distinct channel throughout its course, the posterior spinal arteries ar ...
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Syrinx (medicine)
A syrinx is a rare, fluid-filled neuroglial cavity within the spinal cord ( syringomyelia), in the brain stem ( syringobulbia), or in the nerves of the elbow, usually in a young age. Presentation Symptoms usually begin insidiously between adolescence and age 45. Syringomyelia develops in the center of the spinal cord, causing a central cord syndrome. Pain and temperature sensory deficits occur early but may not be recognized for years. The first abnormality recognized may be a painless burn or cut. Syringomyelia typically causes weakness, atrophy, and often fasciculations and hyperreflexia of the hands and arms; a deficit in pain and temperature sensation in a capelike distribution over the shoulders, arms and back is characteristic. Light touch and position and vibration sensation are not affected. Later, spastic leg weakness develops. Deficits may be asymmetric. Syringobulbia may cause vertigo, nystagmus, unilateral or bilateral loss of facial sensation, lingual atrophy an ...
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Pediatric
Pediatrics (American English) also spelled paediatrics (British English), is the branch of medicine that involves the medical care of infants, children, adolescents, and young adults. In the United Kingdom, pediatrics covers many of their youth until the age of 18. The American Academy of Pediatrics recommends people seek pediatric care through the age of 21, but some pediatric subspecialists continue to care for adults up to 25. Worldwide age limits of pediatrics have been trending upward year after year. A medical doctor who specializes in this area is known as a pediatrician, or paediatrician. The word ''pediatrics'' and its cognates mean "healer of children", derived from the two Greek words: (''pais'' "child") and (''iatros'' "doctor, healer"). Pediatricians work in clinics, research centers, universities, general hospitals and children's hospitals, including those who practice pediatric subspecialties (e.g. neonatology requires resources available in a NICU). History ...
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Cauda Equina Syndrome
Cauda equina syndrome (CES) is a condition that occurs when the bundle of nerves below the end of the spinal cord known as the cauda equina is damaged. Signs and symptoms include low back pain, sciatica, pain that radiates down the leg, numbness around the anus, and loss of bowel or bladder control. Onset may be rapid or gradual. The cause is usually a disc herniation in the lumbar spine, lower region of the back. Other causes include spinal stenosis, cancer, major trauma, trauma, epidural abscess, and epidural hematoma. The diagnosis is suspected based on symptoms and confirmed by medical imaging such as MRI or CT scan. CES is generally treated surgically via laminectomy. Sudden onset is regarded as a medical emergency requiring prompt surgical decompression, with delay causing permanent loss of function. Permanent bladder problems, sexual dysfunction or numbness may occur despite surgery. A poor outcome occurs in about 20% of people despite treatment. About 1 in 70,000 people ...
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Median Sacral Artery
The median sacral artery (or middle sacral artery) is a small artery that arises posterior to the abdominal aorta and superior to its bifurcation. Structure The median sacral artery arises from the abdominal aorta at the level of the bottom quarter of the third lumbar vertebra. It descends in the middle line in front of the fourth and fifth lumbar vertebrae, the sacrum and coccyx, ending in the glomus coccygeum (coccygeal gland). Minute branches pass from it, to the posterior surface of the rectum. On the last lumbar vertebra it anastomoses with the lumbar branch of the iliolumbar artery; in front of the sacrum it anastomoses with the lateral sacral arteries, sending offshoots into the anterior sacral foramina. It is crossed by the left common iliac vein and accompanied by a pair of venae comitantes; these unite to form a single vessel that opens into the left common iliac vein. Development The median sacral artery is morphologically the direct continuation of the abdo ...
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Arteria Iliaca Interna
The internal iliac artery (formerly known as the hypogastric artery) is the main artery of the pelvis. Structure The internal iliac artery supplies the walls and viscera of the pelvis, the buttock, the reproductive organs, and the medial compartment of the thigh. The vesicular branches of the internal iliac arteries supply the bladder. It is a short, thick vessel, smaller than the external iliac artery, and about 3 to 4 cm in length. Course The internal iliac artery arises at the bifurcation of the common iliac artery, opposite the lumbosacral articulation, and, passing downward to the upper margin of the greater sciatic foramen, divides into two large trunks, an anterior and a posterior. It is posterior to the ureter, anterior to the internal iliac vein, anterior to the lumbosacral trunk, and anterior to the piriformis muscle. Near its origin, it is medial to the external iliac vein, which lies between it and the psoas major muscle. It is above the obturator nerve. Bran ...
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