Cerebrum : Usmle Gross Anatomy || Relations and External features - Neuroanatomy animations

Summary

This neuroanatomy lecture provides an in-depth exploration of the cerebrum, the largest part of the brain. It covers the structure and features of the cerebral hemispheres, including the interhemispheric fissure, corpus callosum, and lateral ventricles. The cerebrum's surface is described in terms of sulci, gyri, and its division into four main lobes: frontal, temporal, parietal, and occipital. Additional details are given about the cerebrum's external features, including its three surfaces, four borders, and three poles. The lecture also highlights the role of various anatomical structures like the insular cortex and limbic lobe.

Takeaways

• 😀 The cerebrum is the largest part of the brain and occupies the anterior and middle cranial fossa, as well as the supratentorial part of the posterior cranial fossa.
• 😀 The cerebrum consists of two hemispheres separated by the interhemispheric fissure (also known as the medial longitudinal fissure), which contains cerebrospinal fluid and blood vessel branches.
• 😀 The two cerebral hemispheres are connected by the corpus callosum, a major bundle of white matter.
• 😀 Each cerebral hemisphere contains a lateral ventricle filled with cerebrospinal fluid.
• 😀 The surface of the cerebrum is lined by the cerebral cortex, which features gyri (ridges) and sulci (grooves).
• 😀 The cerebrum is divided into four lobes: frontal, temporal, parietal, and occipital, with the frontal lobe occupying the largest portion of its volume.
• 😀 In addition to the four main lobes, some authors consider the insular cortex and cingulate gyrus (with hippocampus) part of the limbic lobe.
• 😀 The medial surface of the cerebrum is flattened, while the inferior surface is irregular and concave, more pronounced at the anterior part.
• 😀 The external surfaces of the cerebrum include the superolateral surface (convex), medial surface (flat), and inferior surface (irregular, divided into orbital and tentorial parts).
• 😀 The cerebrum has four borders: superior, inferolateral, medial orbital, and medial occipital, each defining the separation between different surfaces of the hemisphere.

Q & A

What is the cerebrum and where is it located?

The cerebrum is the largest part of the brain and occupies the anterior and middle cranial fossa, as well as the supratentorial part of the posterior cranial fossa.

What separates the two cerebral hemispheres?

The two cerebral hemispheres are separated by the interhemispheric fissure, also known as the medial longitudinal fissure.

What structures are found within the interhemispheric fissure?

The interhemispheric fissure contains cerebrospinal fluid, the falx cerebri, and midline branches of the anterior and posterior cerebral arteries.

What is the role of the corpus callosum in the cerebrum?

The corpus callosum is a bundle of white matter that connects the two cerebral hemispheres and allows communication between them.

What is the structure of the lateral ventricle in the cerebrum?

Each hemisphere of the cerebrum contains a lateral ventricle, which is a cavity that holds cerebrospinal fluid.

How is the cerebrum's surface divided?

The surface of the cerebrum is divided into grooves called sulci and ridges called gyri.

What are the four main lobes of the cerebrum?

The four main lobes of the cerebrum are the frontal lobe, temporal lobe, parietal lobe, and occipital lobe.

What percentage of the cerebrum's volume does each lobe occupy?

The frontal lobe occupies 41%, the temporal lobe 22%, the parietal lobe 19%, and the occipital lobe 18% of the cerebrum's total volume.

What other structures are sometimes considered part of the cerebrum, aside from the four lobes?

Some authors also refer to the insular cortex and the cingulate gyrus with hippocampus as part of the limbic lobe.

What are the three main surfaces of the cerebrum?

The three main surfaces of the cerebrum are the supralateral surface (convex), the medial surface (flat), and the inferior surface (irregular, with orbital and tentorial parts).