Medial surface of the Cerebral hemisphere - Gyri and sulci | Neuroanatomy

Summary

This script offers a detailed exploration of the brain's medial surface, focusing on key anatomical structures such as the corpus callosum, sulci, and gyri. It describes the four parts of the corpus callosum, from the rostrum to the splenium, and traces the singul sulcus and gyrus, highlighting their roles in brain anatomy. The script also discusses the paracentral lobe, parieto-occipital fissure, and various gyri like the precuneus and lingual gyrus. Additionally, the temporal lobe’s involvement with the fusiform gyrus is mentioned, providing a comprehensive understanding of these brain regions.

Takeaways

• 😀 The corpus callosum is located at the center of the cerebral hemisphere and is divided into four parts: rostrum, genu, body, and spleen.
• 😀 The medial end of the central sulcus (Rolando) is visible above the genu of the corpus callosum.
• 😀 The longest sulcus visible on the medial surface of the cerebral hemisphere is the cingulate sulcus, which begins inferior to the genu of the corpus callosum.
• 😀 The cingulate sulcus ascends anterior to the genu, then above the body of the corpus callosum and central sulcus.
• 😀 The cingulate gyrus is located beneath the cingulate sulcus, with its thinnest part found under the spleen.
• 😀 The medial frontal gyrus is located above the cingulate sulcus and in front of the precentral sulcus.
• 😀 The paracentral lobe lies between the precentral sulcus and the ascending part of the cingulate sulcus.
• 😀 The parieto-occipital fissure divides the parietal and occipital lobes on the medial surface of the brain.
• 😀 The occipital lobe is divided by the calcarine fissure, which lies between the parieto-occipital fissure and the calcarine fissure.
• 😀 The fusiform gyrus represents both the medial and lateral occipital temporal gyrus, forming a collective structure called the fusiform gyrus.

Q & A

What is the corpus callosum and where is it located in the brain?

The corpus callosum is the primary commissural region of the brain, located at the center of the cerebral hemisphere. It connects the left and right sides of the brain and consists of four parts: the rostrum, genu, body, and splenium, from anterior to posterior.

What is the role of the medial end of the central sulcus of Rolando?

The medial end of the central sulcus of Rolando is visible above the anterior part of the corpus callosum. It marks a significant landmark in the brain’s anatomy, separating the frontal and parietal lobes.

Where does the singular sulcus begin, and what is its path?

The singular sulcus begins inferior to the genu of the corpus callosum. It ascends anterior to the genu, passing above the body of the corpus callosum, and continues around the central sulcus (Rolando).

What does the singular gyrus represent and where is it located?

The singular gyrus is located under the singular sulcus and winds around the corpus callosum. Its thinnest part is located just beneath the splenium of the corpus callosum.

What is the function and location of the medial frontal gyrus?

The medial frontal gyrus is located above the singular sulcus and in front of the precentral sulcus on the superolateral surface of the brain. It plays a role in motor control and higher cognitive functions.

What is the paracentral lobe, and where is it situated?

The paracentral lobe is situated between the precentral sulcus and the ascending part of the singular sulcus. It is located in the medial region of the cerebral hemisphere, and it is involved in motor functions.

Where is the parieto-occipital fissure located?

The parieto-occipital fissure is located on the medial surface of the brain, dividing the parietal and occipital lobes.

What is the calcarine fissure and where can it be found?

The calcarine fissure is a horizontal fissure that divides the occipital lobe on the medial surface of the brain. It lies between the parieto-occipital fissure and the calcarine fissure gyrus.

What is the precuneus and where is it located?

The precuneus is a gyrus located in front of the parieto-occipital fissure. It is part of the parietal lobe and has numerous smaller sulci within it.

What is the fusiform gyrus, and how is it divided?

The fusiform gyrus is a brain structure located on the medial and lateral occipitotemporal regions. It represents both the medial occipital-temporal gyrus and the lateral occipital-temporal gyrus, which are collectively referred to as the fusiform gyrus.