[Music] in the developing embryo the neural tube forms then along gates to form the long length of the spinal cord and then enlarges and expands into the brain at the cranial end our brain serves as the control center for our bodies there are nerves connected directly to the brain as well as the spinal cord which contain even more branching nerves when you look at the outside of the brain you probably first notice the large cerebral hemispheres which contain four lobes on each side the frontal lobe parietal lobe occipital lobe and temporal lobe beneath the cerebrum is a round structure that looks like a miniature brain it's called the cerebellum and protecting from the base is the brainstem a cross section of the brain reveals unique shapes and structures on the inside we can still see the cerebrum in the branched insides of the cerebellum but I'll also highlight some key regions like the hypothalamus medulla oblongata pituitary gland and the deeply hidden pineal gland these structures are interesting to look at but more interesting to know what they do but how do we know what these parts of the brain do for centuries humans relied on accidents and brain trauma to reveal what regions of the brain do Phineas Gage had a long iron rod shoot through his head in an accident while building a railroad he survived the accident despite the fact that the rod shot through his frontal lobe and took brain tissue with it his personality changed greatly after the accident which helps scientists understand what the damaged region of the brain normally does much research both ethical and unethical has been performed on animals as well and though autopsies were taboo for centuries Andreas Vesalius shifted that norm in the 15th century studying the brains of deceased patients who died from tumors or lesions have revealed key information about the brain but a non-invasive technology called the functional MRI has been useful in more recent years this technology will reveal where increased blood flow occurs in the brain which allows scientists to track where active regions of thought take place with all this information we know many functions of the brain regions the cerebral hemispheres perform high complex functions such as learning memory and emotion the frontal lobes are involved in motor function memory speech problem-solving language judgment impulse control and social and sexual behavior the parietal lobes of the brain are major regions for processing sensations and perceptions as well as language processing the occipital lobes are the visual processing centers and the temporal lobes are responsible for processing auditory information the cerebellum coordinates unconscious functions including posture balance and body coordination the hypothalamus regulates hormones via the pituitary gland and regulates body temperature the pituitary gland releases hormones synthesized by the hypothalamus and hormones that regulate many body functions the pineal gland produces and regulates melatonin which is an important sleep hormone and the medulla oblongata is used in autonomic control of gut muscle breathing blood vessels and heart muscle but what do we mean by autonomic the peripheral nervous system which includes all the nerves outside the brain and spinal cord is divided into two parts the autonomic and voluntary systems autonomic means they happen without having to actively think about it you don't have to think about breathing when you sleep for example voluntary means you have control over the action you can voluntarily alter the speed and depth of your breathing the autonomic system is additionally divided into the sympathetic and parasympathetic systems which have opposite actions the sympathetic system will get your body ready for fight-or-flight pumping you with adrenaline and blood flow to your muscles the parasympathetic is the rest and digest system which calms you back down brings blood flow to the gut the medulla oblongata is the control center for the autonomic system while the first phase of swallowing is voluntary the medulla controls the involuntary movement of food through the esophagus and into the stomach the medulla also controls both the timing and forcefulness of your breathing and in the heart the medulla regulates the heartbeat by monitoring blood pH and pressure and responding by sending signals to the hearts pacemaker the medulla oblongata also controls the pupil reflex your eye has muscles that can contract and relax to change the shape of the hole in your eye called a pupil in dim light the muscles relax and widen or dilate the pupil in bright light the muscles contract and shrink or constrict the pupil if a person experiences head trauma that has caused brain damage like a concussion their pupils will not respond to bright light there are other regions of the brain that have key functions but are specific regions in larger structures the visual cortex is located on the occipital lobes and processes visual information to perform pattern recognition and judge the speed of moving objects Broca's area is part of the dominant frontal lobe usually the left lobe near the temporal lobe which controls the production of speech damage to this area means that even though a person knows what they want to say they cannot articulate the words or sounds the nucleus accumbens is in each of the cerebral hemispheres and is the pleasure or reward center of the brain things like food and sex can cause the release of dopamine neurotransmitter which causes feelings of pleasure and satisfaction the area is also hijacked by drugs like cocaine heroin and nicotine by activating the release of dopamine in the nucleus accumbens thanks for watching this episode of teacher's pet don't forget to Like and subscribe and follow me on Twitter at science pet