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Jai Ganesh

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Cerebrum

Cerebrum

Gist

The cerebrum is the largest part of the human brain, responsible for higher functions like thought, memory, language, and voluntary movement, divided into two hemispheres (left/right) connected by the corpus callosum, and further split into four lobes (frontal, parietal, temporal, occipital) that manage sensory input and conscious actions. Its wrinkled outer layer (cerebral cortex) of grey matter allows for complex processing, while the inner white matter facilitates communication. 

The cerebrum is the largest part of the human brain, responsible for higher functions like thought, memory, senses, and voluntary movement, divided into two hemispheres (left and right) and further into four lobes (frontal, parietal, temporal, occipital) that process different types of information. Its folded outer layer, the cerebral cortex (gray matter), increases surface area for complex processing and allows us to think, plan, learn, speak, and feel emotions. 

Summary

Cerebrum is the largest and uppermost portion of the brain. The cerebrum consists of the cerebral hemispheres and accounts for two-thirds of the total weight of the brain. One hemisphere, usually the left, is functionally dominant, controlling language and speech. The other hemisphere interprets visual and spatial information.

The cerebral hemispheres consist of an inner core of myelinated nerve fibres, the white matter, and an outer cortex of gray matter. The cerebral cortex is responsible for integrating sensory impulses, directing motor activity, and controlling higher intellectual functions. The human cortex is several centimetres thick and has a surface area of about 2,000 square cm (310 square inches), largely because of an elaborate series of convolutions; the extensive development of this cortex in humans is thought to distinguish the human brain from those of other animals. Nerve fibres in the white matter primarily connect functional areas of the cerebral cortex. The gray matter of the cerebral cortex usually is divided into four lobes, roughly defined by major surface folds. The frontal lobe contains control centres for motor activity and speech, the parietal for somatic senses (touch and position), the temporal for auditory reception and memory, and the occipital for visual reception. Sometimes the limbic lobe, involved with smell, taste, and emotions, is considered to be a fifth lobe.

Numerous deep grooves in the cerebral cortex, called cerebral fissures, originate in the extensive folding of the brain’s surface. The main cerebral fissures are the lateral fissure, or fissure of Sylvius, between the frontal and temporal lobes; the central fissure, or fissure of Rolando, between the frontal and parietal lobes, which separates the chief motor and sensory regions of the brain; the calcarine fissure on the occipital lobe, which contains the visual cortex; the parieto-occipital fissure, which separates the parietal and occipital lobes; the transverse fissure, which divides the cerebrum from the cerebellum; and the longitudinal fissure, which divides the cerebrum into two hemispheres.

A thick band of white matter that connects the two hemispheres, called the corpus callosum, allows the integration of sensory input and functional responses from both sides of the body. Other cerebral structures include the hypothalamus, which controls metabolism and maintains homeostasis, and the thalamus, a principal sensory relay centre. These structures surround spaces (ventricles) filled with cerebrospinal fluid, which helps to supply the brain cells with nutrients and provides the brain with shock-absorbing mechanical support.

Details

The cerebrum (pl.: cerebra), telencephalon or endbrain is the largest part of the brain, containing the cerebral cortex (of the two cerebral hemispheres) as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In the human brain, the cerebrum is the uppermost region of the central nervous system. The cerebrum develops prenatally from the forebrain (prosencephalon). In mammals, the dorsal telencephalon, or pallium, develops into the cerebral cortex, and the ventral telencephalon, or subpallium, becomes the basal ganglia. The cerebrum is also divided into approximately symmetric left and right cerebral hemispheres.

With the assistance of the cerebellum, the cerebrum controls all voluntary actions in the human body.

Structure

The cerebrum is the largest part of the brain. Depending upon the position of the animal, it lies either in front or on top of the brainstem. In humans, the cerebrum is the largest and best-developed of the five major divisions of the brain.

The cerebrum is made up of the two cerebral hemispheres and their cerebral cortices (the outer layers of grey matter), and the underlying regions of white matter. Its subcortical structures include the hippocampus, basal ganglia and olfactory bulb. The cerebrum consists of two C-shaped cerebral hemispheres, separated from each other by a deep fissure called the longitudinal fissure.

Cerebral cortex

The cerebral cortex, the outer layer of grey matter of the cerebrum, is found only in mammals. In larger mammals, including humans, the surface of the cerebral cortex folds to create gyri (ridges) and sulci (furrows) which increase the surface area.

The cerebral cortex is generally classified into four lobes: the frontal, parietal, occipital and temporal lobes. The lobes are classified based on their overlying neurocranial bones. A smaller lobe is the insular lobe, a part of the cerebral cortex folded deep within the lateral sulcus that separates the temporal lobe from the parietal and frontal lobes, is located within each hemisphere of the mammalian brain.

Cerebral hemispheres

The cerebrum is divided by the medial longitudinal fissure into two cerebral hemispheres, the right and the left. The cerebrum is contralaterally organized, i.e., the right hemisphere controls and processes signals (predominantly) from the left side of the body, while the left hemisphere controls and processes signals (predominantly) from the right side of the body. According to current knowledge, this is due to an axial twist that occurs in the early embryo. There is a strong but not complete bilateral symmetry between the hemispheres, while lateralization tends to increase with increasing brain size. The lateralization of brain function looks at the known and possible differences between the two.

Development

In the developing vertebrate embryo, the neural tube is subdivided into four unseparated sections which then develop further into distinct regions of the central nervous system; these are the prosencephalon (forebrain), the mesencephalon (midbrain) the rhombencephalon (hindbrain) and the spinal cord. The prosencephalon develops further into the telencephalon and the diencephalon. The dorsal telencephalon gives rise to the pallium (cerebral cortex in mammals and reptiles) and the ventral telencephalon generates the basal ganglia. The diencephalon develops into the thalamus and hypothalamus, including the optic vesicles (future retina). The dorsal telencephalon then forms two lateral telencephalic vesicles, separated by the midline, which develop into the left and right cerebral hemispheres. Birds and fish have a dorsal telencephalon, like all vertebrates, but it is generally unlayered and therefore not considered a cerebral cortex. Only a layered cytoarchitecture can be considered a cortex.

Additional Information

Your cerebrum is the largest part of your brain and handles conscious thoughts and actions. Different areas within your cerebrum also have different responsibilities like language, behavior, sensory processing and more. Areas of your brain also commonly work together on the same tasks, helping you understand what’s happening in the world around you.

What is the cerebrum?

Your cerebrum is the largest part of your brain, and it handles a wide range of responsibilities. Located at the front and top of your skull, it gets its name from the Latin word meaning “brain.”

Your cerebrum is instrumental in everything you do in day-to-day life, ranging from thoughts to actions. In essence, it’s responsible for the brain functions that allow us to interact with our environment and make us who we are.

Scientists have been studying the brain for years, trying to unlock just how it works and how to diagnose and treat conditions that affect it. While experts know a lot about how the cerebrum works, there’s much that’s not fully understood. Fortunately, advances in technology and medical science have helped drive growth in what experts understand about the brain.

What’s the difference between the cerebellum and cerebrum?

Your cerebrum is the largest part of your brain and includes parts above and forward of your cerebellum. Your cerebrum is the part of your brain that starts and manages conscious thoughts; meaning, things that you actively think about or do.

Your cerebellum is a small part of your brain located at the bottom of this organ near the back of your head. It processes and regulates signals between other parts of your brain and body, and is involved in coordinating functions of your body (for example, walking).

Function:

What does the cerebrum do?

Your cerebrum handles much of your brain’s “conscious” actions. That means it’s responsible for elements that require thinking, including:

* Your five senses: Your cerebrum manages and processes everything your senses take in. That includes sight, sound, smell, taste and touch.
* Language: Various parts of your cerebrum control your ability to read, write and speak.
* Working memory: This is a type of short-term memory. An example of working memory is when you remind yourself to pick up something from the grocery store.
* Behavior and personality: Part of your cerebrum is your frontal lobe, which manages your personality and behavior. It's the part of your brain that acts as a filter to stop you from doing or saying things you might later regret.
* Movement: Certain areas of your cerebrum send signals that tell your muscles what to do when you need to use them.
* Learning, logic and reasoning: Different areas of your cerebrum work together when you need to learn a new skill, make a plan of action or puzzle out a problem.

How does it help with other organs?

Your cerebrum works together with other parts of your brain, especially your cerebellum, to help you with your daily activities. An example of this is picking up a pencil off a table. Your cerebrum sends the signals to the muscles in your arms, and your cerebellum helps calculate and control your movements, so your hand goes right to the pencil without missing.

Your cerebellum not only manages conscious thoughts, but also planning and actions. That includes when you decide to be physically active, choose what to eat for a meal or set aside time to see a healthcare provider for any reason. Because of this, your cerebrum plays a critical role in the health and well-being of your entire body.

What are some interesting facts about the cerebrum?

* Crossed representation. When you do something with one side of your body, the other side of your brain is usually behind that process. An example of this is having a stroke on the left side of your brain and feeling its effects on the right side of your body.

* Your brain is very adaptable. Your brain can “rewire” itself. This ability can happen as you learn new skills or help you recover from injuries to your brain.

* Your brain has specialized areas. Different parts of your brain are responsible for different abilities and skills. However, that’s also fed into the disproven myth that some people are “left-brained” or “right-brained.”

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