Anatomy & Organs

Cerebral Cortex – Structure, Function & Diseases

Cerebral cortex

The cerebral cortex is the outermost layer of the human cerebrum. The term comes from the Latin cortex (bark) cerebri (brain) and is often abbreviated as cortex.

What is the cerebral cortex?

The human cerebrum comprises about 85 percent of the entire brain mass and is the youngest part of the brain in terms of evolutionary history . The overlying cerebral cortex takes on a variety of tasks of human sensory perception and, due to its large area, takes up about half of the entire brain volume. The cortex is also known as gray matter because of its high number of nerve cells , which paint it a reddish-brown to gray color.

The number of nerve cells in the cerebral cortex ranges from 19 to 23 billion, depending on the size and gender of the person. The nerve cells in the cerebral cortex process coded signals from the body’s individual sensory organs and convert them into specific impressions. The cerebral cortex is therefore an essential part of our sensory perception. Some scientists also think they can locate the seat of consciousness in the front cerebral cortex. However, this research hypothesis, like the enigma of consciousness itself, is highly controversial.

Anatomy & Structure

The cerebrum, divided into two mirror-similar halves, the so-called hemispheres, stretches from the forehead area over the sides to the back of the head and is located above the thalamus , hypothalamus , brainstem and cerebellum . The cerebral cortex, which encases the cerebrum, is a layer two to five millimeters thick with numerous folds and convolutions. This fold allows for maximum surface area expansion in the limited space of the skull .The average human cortex is 1800 square centimetres. The characteristic structure of the cerebral cortex evolved slowly over time during the evolution of mammals. One of the oldest parts is the palaeocortex, which is responsible for the perception of smells, which means old cortex. The so-called archicortex, which is often considered part of the limbic system and influences emotional reactions, and the hippocampus , which is crucial for memory, also developed early in history.

However, these ancient parts of the cerebral cortex make up only a tenth of the entire cortex. The remaining 90 percent is called the neocortex, i.e. new cortex. Analogous to the higher development of the sensory organs, such as the skin and mucous membranes, muscles, organs of taste and inner ear, the neocortex became more and more complex in structure and structure.

The entire cerebral cortex can also be roughly divided into four to six lobes, so-called lobes, whose borders form the most prominent folds.

Functions & Tasks

Different tasks are assigned to the different lobes of the cerebral cortex. The temporal lobe (lobus temporalis) is responsible for hearing , smell and speech. The parietal lobe or parietal lobe ( lobus parietalis ) converts signals for taste perception and touch. The rear skin lobe or occipital lobe ( lobus occipitalis ) is active in vision and the frontal lobe or frontal lobe ( lobus frontalis ) is responsible for movement, thought processes and language. In many cases, the cerebral cortex is also divided into two further lobes: the so-called island lobe ( Lobus insularis ) and the limbic lobe (limbic lobe ). The former takes over the processing of chemical stimuli through smell and taste, as well as crucial tasks in the sense of balance. The latter is decisive in the development of emotions and drive behavior and controls the release of endorphins , which can have a pain-relieving and euphoric effect.In the cortex, the signals from the sensory organs are processed with the help of upstream brain regions into coherent impressions and perceptions of the environment. Most of the signals coming from the sensory organs are switched by the nerve cells in the thalamus and forwarded to the responsible “higher” region of the cortex for “translation” into a coherent perception.

The cerebral cortex is also responsible for storing information, so it forms the biological basis of our memory. Mind and thinking, goal-oriented action and the generation of feelings are all products of the processes in our cerebral cortex.

Diseases & Ailments

Our sensory perception is subject to a complex interaction between the cerebral cortex and the sensory organs. If the area in the cortex responsible for a particular sensory organ is damaged, it can happen that, despite a functioning sensory organ, sensory perception is disrupted or completely absent. For example, if the visual center in the cerebral cortex is injured, blindness can result despite fully functional eyes .If certain higher-level areas of the cortex are affected, people can see, but cannot convert what they see into useful information. Due to local interference, for example, it is not able to recognize or distinguish between faces . Damage to the lowest convolution of the frontal lobe can lead to limitations in the ability to speak , but often not in understanding speech. Injuries to the front part of the frontal lobe can cause personality changes or reduce intelligence.

A widespread and unfortunately not yet curable disease that affects the cerebral cortex is Alzheimer’s . In Alzheimer’s patients, protein proteins, so-called neurofibrils, are deposited in the nerve cells of the cortex. They disrupt transport processes in the affected cells, which lead to the death of the nerve cells as the disease progresses.

First of all, the areas responsible for memory and cognitive abilities are usually affected, which often makes Alzheimer’s noticeable through frequent forgetting. Damage to the cerebral cortex can vary greatly in terms of severity and symptoms due to the high complexity and sensitivity of the brain and is the subject of medical research on an ongoing basis.

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.