I. Hypothalamus. II. Hjernebjælken.
III. Grå hjernemasse (Hjernebark).
IV. Hvid hjernemasse.
The brain is located inside the skull and is well protected against external influences. The brain consists of neurons, nerve cell runner and support cells. These are arranged in a very special way so that they can best perform their function. Nerve cells located in what is called the gray substance. It lies mainly in the brain in very windings of the brain. This is called hjernebarken (cortex). There are also gray substance deep in the brain, the so-called nuclei or centers.
Neurons that have the same functions in the same area. Each nerve cell can have hundreds of thousands ramifications for communicating with other neurons. The areas where nerve cell ended the run is called the white substance, and this is located internally in the brain.
One can divide the brain in many different parts that have different functions. Normally we talk about the following:
Big Brain (Cerebrum)
I. Hørecenter. II. Talecenter. III. Bevidsthed,
personlighed, problemløsning. IV. Motorisk
center (Bevægelser styret af viljen).
V. Sensorisk center (Sanseindtyk fra kroppen).
VI. Synscenter. VII. Lillehjernen (Balance og
muskelkoordination). VIII. Rygmarv.
This is the largest and outermost part of the brain. It is in large brain that all the higher functions of the brain lies. Ahead in large brain in pandelappen is the nerve that has to do with our personality, concentration, planning and problem solving. Also located here is a collection of neurons that are involved in our ability to speak, the so-called Brocas speech center.
Around the middle of the brain's surface, the nerve cells that control our voluntary movements, in a tape nedover side of the brain (the motor cortex). Just behind this area is the nerve cells that perceive different sensory input from the body (the sensory cortex). Behind this is an area where there are neurons which are involved in that we can understand speech and use words and language.
Quite the back of the brain is visually bark, where vision worked. On the side of the brain in tindingelappen is hearing center, memory and a region which is involved in the interpretation of sensory input.
Between Brain (Diencephalon)
Inside the center of what is called big brain, can be found between the brain. Between The brain consists of several important areas:
Survey tracks cross each other here.
Thalamus:This is a kind of distribution center for sensory impressions from the rest of the body (except smell). All nerve cell runner bearing the sensory impulses run through here, and some will be modified along the way.
Hypothalamus:Just below the thalamus hypothalamus, which ensures that your body can maintain a stable internal environment. From managed hypothalamus including body temperature, heartbeat, blood pressure, salt and fluid balance, hunger, different glands produce hormones and sleep rhythm.
Pituitary:In a small stalk located in the hypothalamus pituitary, which is a kind of gland, which produces a wide range of hormones.
The brain stem (truncus encephali)
The brain stem is an extension of the brain and is a link between the brain and body (spinal cord). The brain stem contains the nerve cell ramifications that communicates between the brain and the rest of the body. In addition, there are some very important seeds here. Among others are the kernels of all brain nerves, which are the nerves that control the muscles and senses from the neck up. There are also breathing center, which will ensure that we keep breathing, a center,
Spread out in the brainstem is the special vågenhedscenter to ensure that we are awake and can respond to different stimuli.
Little Brain (Cerebellum)
Little Brain is at the back of the skull just below the big brain behind the brainstem. It consists of the brain like the big gray and white substance, where the substance is very gray. In small brain processed some of the sensory impulses, which tells us how physically position the body and its limbs are located. This helps to be able to keep the balance and coordinate its movements. Many of our tillærte movements as walking or cycling, so coordinated from here.
Inside the center of the brain are fluid-filled cavities, which communicate with each other. These are called gastric, and this produced spinalvæsken, completely enclosing the brain and spinal cord. Spinalvæskens function is to protect the brain from shocks but also to provide the right environment for the brain. Among others may waste of the brain into the bloodstream through spinalvæsken. Normally, there is a fine balance between how much spinalvæske, produced and how much, which is led away. If the
I. Halsarterie. II Forreste hjernearterie.
III. Mellemste hjernearterie. IV. Bagerste
hjernearterie. V. Forlængelse rygmarv.
The blood-brain barrier
When brain cells are very sensitive to chemical exposure is protected by the blood-brain barrier, which ensures that harmful substances in the blood can not pass in the brain cells. This barrier lies in the fact that the blood vessels that lead blood to the brain, are unusually close. This means that only drugs which consists of very small molecules or substances that can dissolve in fat, can pass through their wall. This means that some medicines, for example. does not work in the brain, since it can not penetrate ige