vertebral foramen

Examples of vertebral foramen in the following topics:

• Parts of a Vertebra

  • A vertebra consists of two parts: an anterior segment, or the vertebral body; and a posterior part, or the vertebral (neural) arch.
  • When articulated together the vertebrae form a strong yet flexible structure that encloses the vertebral foramen, or opening, where the spinal cord sits.
  • The anterior vertebral body which is the point of articulation between the vertebrae.
  • The posterior vertebral or neural arch that encloses the spinal cord.
  • The intervertebral discs that act as ligaments between the vertebral bodies.

• The Spine

  • Kyphosis is an exaggerated concave (kyphotic) curvature of the thoracic vertebral column; it is commonly known as "humpback."
  • A typical vertebra consists of the vertebral body and vertebral arch.
  • These parts together enclose the vertebral foramen that contains the spinal cord.
  • The vertebral arch is formed by a pair of pedicles and a pair of laminae.
  • Two transverse processes and one spinous process are posterior to (behind) the vertebral body.

• Foramina

  • In anatomy, a foramen is any opening.
  • Supraorbital foramen: Located in the frontal bone, it allows passage of the supraorbital vein, artery, and nerve into the orbit.
  • Optic foramen: Located in the sphenoid, it allows the passage of the ophthalmic artery and nerve from the optic canal into the orbit.
  • Foramen magnum: Located in the occipital bone, it allows the passage of the spinal and vertebral arteries and the spinal cord to pass from the skull into the vertebral column.
  • Foramen rotundum: Located in the sphenoid bone, it allows passage of the maxillary nerve.

• Arteries of the Pelvis and Lower Limbs

  • Formed when the common iliac artery divides the internal iliac artery at the vertebral level L5 descends inferiorly into the lesser pelvis.
  • At the most superior border of the greater sciatic foramen, the large opening to the rear of the pelvis, the internal iliac artery divides into anterior and posterior trunks.

• Branches of Spinal Nerves

  • The meningeal branches (recurrent meningeal or sinuvertebral nerves): These branch from the spinal nerve and re-enter the intervertebral foramen to serve the ligaments, dura, blood vessels, intervertebral discs, facet joints, and periosteum of the vertebrae.

• Cerebrospinal Fluid and Its Circulation

  • It circulates from the lateral ventricles to the foramen of Monro (interventricular foramen), third ventricle, aqueduct of Sylvius (cerebral aqueduct), fourth ventricle, foramen of Magendie (median aperture), foramen of Luschka (lateral apertures), and the subarachnoid space over the brain and the spinal cord.
  • Clearing waste: CSF has been shown by the research group of Maiken Nedergaard to be critical in the brain's glymphatic system, the functional waste clearance pathway for the vertebrate CNS.

• Overview of the Spinal Cord

  • The spinal cord runs along the inside of the vertebral column and serves as the signaling conduit between the brain and the periphery.
  • The birth defect spina bifida is a failure of the vertebral arch to close, exposing the spinal cord.
  • The spinal nerve emerges from the spinal column through the opening (intervertebral foramen) between adjacent vertebrae.
  • The cauda equina ("horse's tail") is the name for the collection of nerves in the vertebral column that extends beyond the cord.
  • Relationship between the spinal cord and vertebral column, delineating the cervical, thoracic, and lumbar sections.

• Overview of the Spinal Nerves

  • Humans have 31 left–right pairs of spinal nerves, each roughly corresponding to a segment of the vertebral column: eight cervical spinal nerve pairs (C1–C8), 12 thoracic pairs (T1–T12), five lumbar pairs (L1–L5), five sacral pairs (S1–S5), and one coccygeal pair.
  • The spinal nerve emerges from the spinal column through an opening (intervertebral foramen) between adjacent vertebrae.
  • Outside the vertebral column, the nerve divides into branches.
  • The meningeal branches (recurrent meningeal or sinuvertebral nerves) branch from the spinal nerve and re-enter the intervertebral foramen to serve the ligaments, dura, blood vessels, intervertebral discs, facet joints, and periosteum of the vertebrae.
  • The anterior divisions of the lumbar nerves (rami anteriores) consist of long, slender branches that accompany the lumbar arteries around the sides of the vertebral bodies, beneath the psoas major.

• Types of Circulatory Systems in Animals

  • The circulatory system varies from simple systems in invertebrates to more complex systems in vertebrates.
  • Closed circulatory systems are a characteristic of vertebrates; however, there are significant differences in the structure of the heart and the circulation of blood between the different vertebrate groups due to adaptation during evolution and associated differences in anatomy.
  • Two other adaptations include a hole in the heart between the two ventricles, called the foramen of Panizza, which allows blood to move from one side of the heart to the other, and specialized connective tissue that slows the blood flow to the lungs.
  • (a) Fish have the simplest circulatory systems of the vertebrates: blood flows unidirectionally from the two-chambered heart through the gills and then to the rest of the body.

• The Evolution of Craniata and Vertebrata

  • Hagfish are the only known living animals that have a skull, but not a vertebral column .
  • Vertebrates are members of the subphylum Vertebrata, the clade Craniata, and the phylum Chordata.
  • Vertebrates display the four characteristic features of chordates, but they are named for the vertebral column composed of a series of bony vertebrae joined together as a backbone .
  • In adult vertebrates, the vertebral column replaces the embryonic notochord.
  • All vertebrates are in the Craniata clade and have a cranium.