The brain (Greek enkephalos) is probably the most complex organ of the human body. In the head that is about 1.3kg heavy, walnut-shaped brain, surrounded by the stable skull bones, which should protect it from external influences. As part of the Central nervous system the brain is the central switching point for all processes taking place in the body.
The weight of the brain is by no means a clue to the intelligence (sperm whale with a 10kg brain), but is mainly determined by the internal interconnection. There is also a difference of about 100g between man and woman in terms of brain weight, but this is due to the woman's overall smaller stature. There is no measurable difference in terms of intelligence.
The consistency of the brain is similar to that of firm jelly. The nerve tissue of the brain consists of 1,000,000,000,000 (one trillion) nerve cells, which are networked via synapses. Each nerve cell is connected to several hundreds of synapses. For example, if we learn something, then the brain constantly recombines. Theoretically, with regard to the immense number of synapses (one hundred trillion: 100,000,000,000,000), there is an unlimited number of possible combinations in the brain.
Because of the Blood-brain barrier The brain is not part of the normal bloodstream. The blood-brain barrier works like a filter, which is only permeable to certain substances (semipermeability). Toxins from the blood can not reach the nerve cells of the brain. Damage would otherwise be fatal and would quickly lead to cognitive losses, or even death. In addition, nerve cells can not regenerate to the extent that e. in skin cells is the case.
Our brain works day and night. From an absolute state of rest can be no question even in sleep. In the night u.a. processed the experiences of the day and integrated into the memory.
About 20% of the daily basal metabolism consumes the brain (basal metabolic rate man: 2400kcal; Energy consumption brain: 480kcal). In terms of the brain's share of total body weight, that's a tremendous amount (2% of the body weight consumes 20% of the energy provided in the form of glucose). Glucose can easily cross the blood-brain barrier with the help of so-called carrier proteins.
Construction / anatomy of the brain
There are many different models for a possible structure of the brain, which use very different criteria for classification. Known is the classification according to the cell structure of Korbinian Brodmann (Brodmann areas), also possible models with phylogenetic (after appearance in the history of development) or functional focus. The following is a simple and simple classification of the brain into the brain, midbrain, midbrain, hindbrain, and hindbrain, with a short (non-exhaustive) selection of individual functions.
Cerebral cortex: can be divided into frontal lobes, parietal lobes, occipital lobes and temporal lobes;
Olfactory brain: place for the processing of odors; The olfactory bulb is also located in the olfactory bulb;
Amygdala: part of the limbic system; significantly involved in the development of anxiety;
Neocortex: The neocortex brings together information that requires different functional areas (for example, writing a letter requires: motor skills, vision, coordination, memory).
Hippocampus: named after its sea horse-like form; every brain half has a hippocampus; Part of the limbic system; et al responsible for the transfer of memories from short-term to long-term memory;
Visual cortex: also known as the visual cortex; this brain area is responsible for the visual process;
Cerebral limb: Entry point for the oculomotor nerve (III cranial nerve, controls the movement of the eyes).
Midbrain hood: u.a. Location of the reticular formation (involved in the perception of pain, the regulation of breathing and the general attention)
Midbrain roof: here is the superior colliculi, which controls eye movements, e.g. saccade reflex or fixation.
Thalamus: the thalamus nuclei transmit information of sense of touch, sense of smell and sense of sight.
Hypothalamus: controls the vegetative nervous system; In addition, seat of the pituitary gland, which provides for a control of hormone secretion.
Subthalamus: crucial brain area for the control of motor skills.
Epithalamus: the seat of pineal glands, which ensures the production of the tired hormone melatonin.
Cerebellum: involved in the coordination of movement. Information from the organ of balance is also processed in the cerebellum.
Pons: also called "bridge"; Part of the brain stem; Some cranial nerves (including facial expressions, hearing, and sense of balance) pass through the pons and from there are further connected to the cerebellum
elongated spinal cord: also called medulla oblongata; belongs to the brainstem and is one of the oldest structures; Location of the respiratory center, the reflex centers (including vomiting reflex and swallowing reflex) and responsible for the control of the blood circulation