The brain only weighs three pounds, but it controls all the functions of the human body. It is part of the central nervous system, which controls breathing, heart flow, digestion, and hormone secretion and excretion, among many others. The brain is also responsible for interpreting information from the outside world and controlling thoughts, speech, memory, movement, and responding to any stimuli.
The brain, which is protected by the skull, is composed of:
Cerebrum or cortex - This is the largest part of the human brain and is divided into four sections namely, temporal, frontal, occipital, and parietal lobes. It is also divided into right and left hemispheres, which are joined by a bundle of fibers called corpus callosum. In general, the right hemisphere controls musical skills and spatial ability, among others, while the left hemisphere controls writing, comprehension, and speech.
Cerebellum – Located at the back of the brain, its main function is to coordinate and regulate muscular activity. It is also involved in the regulation of fear and pleasure responses as well as some cognitive functions such as language and attention.
Limbic system – Buried behind the cerebrum, this part of the brain is composed of the amygdala, hypothalamus, thalamus, and hippocampus.
Brain stem – Composed of medulla, midbrain, and pons, this part of the brain is found just underneath the limbic system and is responsible for the heartbeat, breathing, and blood pressure.
Brain diseases come in many forms, and can be categorized as follows:
Brain Injuries - These include concussion, trauma, and intra-cerebral hemorrhage (bleeding). Brain injuries can cause headaches, memory problems, personality/mood changes, and even stroke.
Epilepsy - A condition characterized by recurring seizures due to excessive or abnormal electrical impulses in the brain. Epilepsy can be caused by a genetic condition, head injury, stroke or brain infection.
Brain tumors – This refers to an abnormal tissue growth in the brain. Regardless if they are benign or malignant, these cause problems as they place undue pressure on the brain and skull.
Neurodegenerative diseases - This class of brain diseases causes the brain cells and nerves to slowly deteriorate, causing a variety of symptoms. Examples are Huntington's disease, Parkinson's disease, Alzheimer's disease (characterized by loss of memory and mental function), and dementia (decline in cognitive function).
Vascular brain conditions – These are brain diseases that are linked to problems in the blood vessels and include:
Brain aneurysms - When a blood vessel in the brain develops a weakened area that swells up and ruptures causing a stroke
Brain autoimmune conditions - Brain disease caused by autoimmune factors. Examples are vasculitis (vascular inflammation) and multiple sclerosis (when the body damages its own nerves).
Craniotomy – This is a type of surgery that involves making an incision in the scalp and a hole in the skull (bone flap) near the area being treated. This is used to remove brain tumors, drain blood or fluid, clip an aneurysm, or remove abnormal brain tissue.
Brain biopsy - In this procedure, a small amount of brain tissue or a tumor is removed from the brain. The removed mass is then examined by a pathologist to determine whether it is malignant or benign.
Endonasal endoscopic surgery - A minimally invasive brain surgery where tumors or lesions in the brain are removed through the nose and sinuses.
Neuroendoscopy - Similar to endonasal surgery, this procedure is also a minimally invasive method of removing brain tumors. Instead of a large incision like in craniotomy, only small-sized holes are made in the skull to access affected areas.