Gehirn

Gehirn, German for brain, is the central organ of the vertebrate nervous system. It is enclosed by the skull and protected by the meninges and cerebrospinal fluid. The Gehirn integrates sensory information, coordinates movement, and supports cognition, memory, language, and emotion. In humans it comprises the cerebrum, cerebellum, brainstem, and interconnected networks.

Anatomy: The cerebrum, divided into left and right hemispheres, contains four lobes: frontal, parietal, temporal, and occipital. The cerebral cortex covers the cerebrum, with subcortical structures such as the thalamus, hypothalamus, basal ganglia, hippocampus, and amygdala beneath. The cerebellum lies at the back and coordinates balance and refined movement. The brainstem (midbrain, pons, medulla) governs basic life functions and routes motor and sensory pathways.

Physiology and development: Neurons and glia communicate via synapses and neurotransmitters. Plasticity enables learning and adaptation. The Circle of Willis, arising from the internal carotid and vertebrobasilar systems, provides cerebral blood flow; the blood-brain barrier protects neural tissue. Brain development proceeds through embryogenesis, maturation of neural circuits, and lifelong plasticity.

Clinical and research notes: Injuries and diseases—such as stroke, trauma, Alzheimer’s, and Parkinson’s—affect many functions. Research uses MRI, fMRI, CT, PET, EEG, and electrophysiology to map structure and function and to study connectivity. Understanding the Gehirn supports medicine, education, and the comprehension of human behavior.