What is the anterior white commissure?

The anterior white commissure (ventral white commissure) is a bundle of nerve fibers which cross the midline of the spinal cord just anterior (in front of) to the gray commissure (Rexed lamina X).

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Besides, what is the anterior commissure?

The anterior commissure (also known as the precommissure) is a white matter tract (a bundle of axons) connecting the two temporal lobes of the cerebral hemispheres across the midline, and placed in front of the columns of the fornix.

is the anterior commissure gray or white? The anterior commissure (AC) is a transversely oriented commissural white matter tract that connects the two cerebral hemispheres along the midline.

Consequently, where is the white commissure?

The anterior or ventral white commissure is a collection of nerve fibers that cross the midline of the spinal cord and transmit information from or to the contralateral side of the brain. It is present throughout the length of the spinal cord and lies behind the anterior median fissure.

Where is the anterior commissure located in the brain?

The anterior commissure is located in the anterior wall of the third ventricle at the upper end of the lamina terminalis. It runs across the midline in front of the anterior columns of the fornix, above the basal forebrain and beneath the medial and ventral aspect of the anterior limb of the internal capsule.

Related Question Answers

What does the fornix do?

The fornix (meaning "arch" in Latin) is a C-shaped bundle of nerve fibers in the brain that acts as the major output tract of the hippocampus. The fornix also carries some afferent fibres to the hippocampus from structures in the diencephalon and basal forebrain. The fornix is part of the limbic system.

What is a commissure in the brain?

A commissure (/ˈk?m???r/) is the location at which two objects abut or are joined. The term is used especially in the fields of anatomy and biology. The five are the anterior commissure, posterior commissure, corpus callosum, commissure of fornix (hippocampal commissure), and habenular commissure.

What is anterior commissure of larynx?

Anterior commissure of the larynx. The anterior commissure of the larynx is the anterior junction point of the true vocal cords. It is bounded anteriorly by the thyroid cartilage and is part of the laryngeal glottis.

What are Commissural fibers?

The commissural fibers or transverse fibers are axons that connect the two hemispheres of the brain. In contrast to commissural fibers, association fibers connect regions within the same hemisphere of the brain, and projection fibers connect each region to other parts of the brain or to the spinal cord.

Is corpus callosum white matter?

The corpus callosum is the largest collection of white matter within the brain, and it has a high myelin content. Myelin is a fatty, protective coating around nerves that facilitates quicker transmission of information. White matter should not be confused with gray matter.

What kind of matter is corpus callosum?

Corpus callosum is a large C shape white matter that divides the cerebral cortex into the right and left hemispheres. It is an essential part of the human brain, structurally as well as functionally. It forms the floor of the longitudinal fissure that separates the left and right hemispheres.

What is the hippocampal commissure?

The hippocampal commissure is a large bundle of axons that connects the right and left Hippocampal Formations. At the midline, the hippocampal commissure is also known as the Body of the Fornix. Away from the midline, the fibers of the hippocampal commissure are often called the Fimbria.

Is the corpus callosum composed of gray matter?

The outer layer, the cerebral cortex, is made of nerve fibers called gray matter. A mass of nerve fibers known as the corpus callosum connects the two hemispheres and allows communication between the two. The surface of the cerebrum is made up of gyri and sulci.

What is Lissauer tract?

Answer: Lissauer's tract is a white matter tract in the spinal cord that projects up or down across one or two spinal segments. The white matter bundles that only project within the spinal cord are called Lissauer's tract, or the posterolateral tract. These axons mostly carry crude touch and pressure information.

What does the anterior Spinothalamic tract do?

The anterior spinothalamic tract, also known as the ventral spinothalamic fasciculus, is an ascending pathway located anteriorly within the spinal cord, primarily responsible for transmitting coarse touch and pressure.

What is the gray commissure?

The grey commissure is a thin strip of grey matter that surrounds the central canal of the spinal cord and, along with the anterior white commissure, connects the two halves of the cord.

What is the dorsal horn?

Medical Definition of dorsal horn : a longitudinal subdivision of gray matter in the dorsal part of each lateral half of the spinal cord that receives terminals from some afferent fibers of the dorsal roots of the spinal nerves. — called also dorsal column, posterior column, posterior gray column, posterior horn.

What is Decussation?

Definition of decussation. 1 : the action of crossing (as of nerve fibers) especially in the form of an X. 2 : a crossed tract of nerve fibers passing between centers on opposite sides of the nervous system.

What is anterior white column?

Introduction. The anterior or ventral white commissure is a collection of nerve fibers that cross the midline of the spinal cord and transmit information from or to the contralateral side of the brain. It is present throughout the length of the spinal cord and lies behind the anterior median fissure.

Where does the anterior corticospinal tract Decussate?

Fibers that travel in the anterior corticospinal tract do not decussate in the pyramidal decussation and instead continue down to the spinal cord on the ipsilateral side of the brainstem from where they originated. The anterior corticospinal tract is involved in controlling proximal muscles, like those of the trunk.

Where do the Spinothalamic tracts cross?

The axons of the tract cells cross over (decussate) to the other side of the spinal cord via the anterior white commissure, and to the anterolateral corner of the spinal cord (hence the spinothalamic tract being part of the anterolateral system).

What is dorsal column?

Dorsal columns: AKA posterior columns, the dorsal columns refers to the posterior spinal cord, which contains ascending sensory pathways that carry information about tactile sensations and proprioception.

Is the anterior commissure gray matter?

Gross anatomy The AC corresponds to a white matter tract almost completely surrounded by gray matter that crosses the midline just ventral to the supraoptic recess of the third ventricle and the columns of the fornix. It ends in the amygdaloid nucleus of the temporal pole bilaterally ².

Is thalamic nuclei white or gray matter?

Conclusion/Summary. Thalamus is a large egg-shaped mass of grey matter, having a small amount of white matter located at the base of the forebrain, just above the midbrain. It is a part of the diencephalon and is located lateral to the third ventricle.