cerebral aqueduct

Examples of cerebral aqueduct in the following topics:

• Ventricles

  • CSF is produced by modified ependymal cells of the choroid plexus found in all components of the ventricular system except for the cerebral aqueduct and the posterior and anterior horns of the lateral ventricles.
  • CSF flows from the lateral ventricles via the foramina of Monro into the third ventricle, and then into the fourth ventricle via the cerebral aqueduct in the brainstem.
  • The aqueduct between the third and fourth ventricles is very small, as are the foramina.
  • The cerebral aqueduct is formed from the part of the neural canal that does not expand and remains the same at the level of the midbrain superior to the fourth ventricle.
  • Lateral and anterior views of the brain ventricles, including the third and fourth ventricle, lateral ventricles, interventricular foramen, cerebral aqueduct, and central canal.

• Midbrain

  • The midbrain is located below the cerebral cortex and above the hindbrain placing it near the center of the brain.
  • It extends from the substantia nigra to the cerebral aqueduct (also called the ventricular mesocoeli).
  • The cerebral peduncles assist in motor movement refinement, motor skill learning, and converting proprioceptive information into balance and posture maintenance.
  • Throughout embryonic development, the cells within the midbrain continually multiply and compress the still-forming aqueduct of sylvius or cerebral aqueduct.
  • Partial or total obstruction of the cerebral aqueduct during development can lead to congenital hydrocephalus.

• Development of the Central Nervous System

  • The tectum, pretectum, cerebral peduncle, and other structures develop out of the mesencephalon, and its cavity grows into the mesencephalic duct (cerebral aqueduct).

• Trochlear (IV) Nerve

  • The nucleus of the trochlear nerve is located in the caudal mesencephalon beneath the cerebral aqueduct.

• Spinal Cord White Matter

  • Cerebral and spinal white matter do not contain dendrites, which can only be found in grey matter along with neural cell bodies, and shorter axons.
  • Commissural tracts cross from one cerebral hemisphere to the other through bridges called commissures.
  • Aggregates of gray matter such as the basal ganglia and brain stem nuclei are spread within the cerebral white matter.
  • The fluid-filled cerebral ventricles (lateral ventricles, third ventricle, cerebral aqueduct, and fourth ventricle) are also located deep within the cerebral white matter.

• Cerebrospinal Fluid and Its Circulation

  • It acts as a cushion or buffer for the cortex, providing a basic mechanical and immunological protection for the brain inside the skull and serving a vital function in cerebral autoregulation of cerebral blood flow.
  • 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.
  • When CSF pressure is elevated, cerebral blood flow may be constricted.
  • This diagram indicates the (1) posterior medullary velum (2) choroid plexus (3) cisterna cerebellomedullaris of subarachnoid cavity (4) central canal (5) corpora quadrigemina (6) cerebral peduncle (7) anterior medullary velum (8) ependymal lining of ventricle (9) cisterna pontis of subarachnoid cavity

• Blood Flow in the Brain

  • Cerebral circulation is the movement of blood through the network of blood vessels supplying the brain, providing oxygen and nutrients.
  • Cerebral circulation refers to the movement of blood through the network of blood vessels supplying the brain.
  • Since the brain is very vulnerable to compromises in its blood supply, the cerebral circulatory system has many safeguards.
  • The amount of blood that the cerebral circulation carries is known as cerebral blood flow (CBF).

• Overview of the Cerebrum

  • The cerebrum contains the cerebral cortex (of the two cerebral hemispheres), as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb.
  • In larger mammals, the cerebral cortex is folded into many gyri and sulci, which allows it to expand in surface area without taking up much greater volume.
  • Each hemisphere of the mammalian cerebral cortex can be broken down into four functionally and spatially defined lobes: frontal, parietal, temporal, and occipital.
  • Speech and language are mainly attributed to parts of the cerebral cortex.
  • The cerebral cortex is the outer layer depicted in dark violet.

• Cerebral Lobes

  • The frontal lobe contains most of the dopamine-sensitive neurons in the cerebral cortex.
  • The two occipital lobes are the smallest of the four paired lobes in the human cerebral cortex.
  • The temporal lobe is a region of the cerebral cortex located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain.
  • The superior temporal gyrus includes an area where auditory signals from the ear first reach the cerebral cortex and are processed by the primary auditory cortex in the left temporal lobe.
  • Distinguish between the frontal, temporal, parietal, and occipital lobes of the cerebral cortex

• Parts of the Cerebellum

  • The cerebellum has the appearance of a separate structure attached to the bottom of the brain, tucked underneath the cerebral hemispheres.
  • The surface of the cerebellum is covered with finely spaced parallel grooves, in striking contrast to the broad irregular convolutions of the cerebral cortex.
  • Like the cerebral cortex, the cerebellum is divided into two hemispheres.
  • It sends fibers to deep cerebellar nuclei that in turn project to both the cerebral cortex and the brain stem, thus providing modulation of descending motor systems.
  • It receives input exclusively from the cerebral cortex (especially the parietal lobe) via the pontine nuclei (forming corticopontocerebellar pathways), and sends output mainly to the ventrolateral thalamus (in turn connected to motor areas of the premotor cortex and primary motor area of the cerebral cortex) and to the red nucleus.