The brain is the most complex part of the body. It controls our movements, communication, decisions and emotions, as well as our organs. Neuroscientists from Duke University write that the human brain is composed of six basic parts: the medulla oblongata, the pons, the midbrain, the cerebellum, the diencephalon and the cerebrum.
Different brain parts often work together to control the body's actions. Large areas are devoted to complex functions, such as the ability to have thoughts and feelings, to express them using language and to store them in memory. Neuroscientists are still working on deciphering which parts of the brain work together to accomplish such functions.
The medulla oblongata controls the lungs, the heart and blood pressure and contains reflex centers involved in vomiting, coughing, sneezing and swallowing.
"Pons" means "bridge" in Latin, and the pons functions as a bridge between different parts of the brain. It also controls sleep and consciousness, breathing, bladder control, hearing, equilibrium, taste, swallowing, eye movement and the secretion of saliva and tears.
The midbrain, together with the pons and the medulla, builds the brainstem, and contains several parts. The tectum controls eye movement, auditory and visual reflexes and processing. The tegmentum controls reflexes. The cerebral peduncles influence voluntary motor functions. The Substantia negra produces dopamine, which controls many functions in the brain, including behavior, cognition, voluntary movement, sleep, mood, attention and learning.
The cerebellum, or "little brain," is involved in the regulation and coordination of movement, posture, balance and motor learning.
Two important structures of the diencephalon are the thalamus and the hypothalamus. The thalamus serves as a relay between the cerebral cortex and other parts of the brain. All sensory signals except smell enter the thalamus, and its neurons send them further to the cerebral cortex for processing.
The hypothalamus is involved in homeostasis, or the body’s equilibrium, emotions, thirst, hunger and circadian rhythms, or the body's sleep/wake cycle. It also regulates the autonomic nervous system that controls the inner organs. The hypothalamus controls the pituitary gland, which produces hormones that influence other hormone-producing glands.
The cerebrum, together with the diencephalon, builds the forebrain. The cerebrum is the largest part of the human brain, and is associated with higher brain functions, including thinking. The outermost part of the brain is the cerebral cortex. The cortex has two hemispheres: the left, which controls the right side of the body, and the right, which controls the left side. The right side is more artistic, while the left is more rational.
The cortex is divided into four sections or lobes. The frontal lobe is associated with reasoning, planning, problem solving, language and higher emotions, such as empathy and altruism. The parietal lobe controls movement, orientation, visual attention and perception of pain and touch. The occipital lobe controls visual sensation and processing, and the temporal lobe is associated with hearing, speech, memory and emotion.
Buried in the cerebrum is the limbic system, the “emotional brain.” It contains the amygdala and the hippocampus, as well as parts of the thalamus and the hypothalamus. The amygdala is involved in emotions such as happiness and fear, and in storing emotional memories. The hippocampus is important for memory and learning and for interpreting spatial relationships.