There is a lot to cover in even just a discussion of basic brain anatomy, and there will be a lot of new words that are important to understand, therefore this section will include plenty of pictures and diagrams, as well as several videos that are very comprehensive in their breakdown of the brain structures we will be discussing. First it is important to understand some of the new terminology that you will be introduced to in studying brain anatomy. One of the important aspects of this terminology is the language used to describe the orientation of various structures of the brain in relation to their body location. The terms most often used to describe these locations are dorsal, ventral, anterior, posterior, medial, and lateral (a comprehensive list is included in the table below). Structures that are described as dorsal are those located towards the top of the brain, whereas those described as ventral are ones that are located towards the bottom. Those structures that are anterior are towards the front of the brain, and those that are posterior are located towards the back. Finally, structures that are referred to as medial are located towards the middle of the brain, and lateral structures towards the side of the brain. The picture and table below will help show these positions and give greater detail as to the orientation terms included in discussions of brain anatomy.
The first division of the brain that will be discussed is the division of the Forebrain, Midbrain, and Hindbrain. The picture below shows these three areas of the brain, along with some of the structures included within that area. Starting with the hindbrain this is the oldest part of our brain in evolutionary terms. It is located at the top of our spinal cord, this was our most basic brain going all the way back to our distant, distant distant ancestors, and therefore it controls many of our most basic functions. Some of the structures that need to be highlighted int he hindbrain are the Medulla Oblongata, the Pons, and the Cerebellum. The Medulla Oblongata helps to control functions that keep us alive, such as heart rate, breathing, and blood pressure. The Pons is located just above the Medulla, and it helps to bridge communication between the hindbrain and the midbrain. The Pons is a cluster of neuronal fibres that surround the reticular formation, it monitors sleep and helps coordinate the autonomic nervous system. Finally, the Cerebellum, which is located behind the Medulla, it is responsible for coordinating motor activity, balance, and fine muscle movements. Next the Midbrain, which is located in the middle of our brain, it is responsible for a number of functions, two of the major functions are the coordination of sensory information and the functioning of the Reticular Formation which controls arousal between waking and sleep. The midbrain helps to manage incoming sensory information such as sight, with the coordination of simple movements such as the movement of eyes and head to track these words on the page. The Reticular Formation is involved with behaviour such as walking, sleeping, and other reflexes. Finally, the Forebrain, the "newest" part of our brain, those parts that have evolved most recently and control our higher level thinking. There are obviously many important functions controlled by the Forebrain, it processes complex information and is composed of the limbic system, the thalamus, the hypothalamus, the basal ganglia, and the cerebral cortex. The Limbic system is made up of the amygdala and the hippocampus, the amygdala is responsible for processing emotions, our awareness of them and how we express them. It also helps us to recognize, or discriminate between objects, damage to the area will lead to inappropriate responses to objects or stimuli. The hippocampus is involved in memory storage, particularly the formation and storage of new information and memories. The thalamus sits on the top of the brain stem, it sorts and relays incoming information to the various parts of the Forebrain. This information includes sensation, spatial sense, and motor signals to the cerebral cortex, and helps to regulate consciousness, sleep, and alertness. The hypothalamus, which is located just below the thalamus. It monitors pleasurable activities such as eating, drinking, and sex. It influences the endocrine system, in particular the pituitary gland, it helps to secrete hormones that respond to different emotions, stress, and rewarding feelings. The basal ganglia a cluster of neurons, located between the thalamus and the cerebral cortex, works between the cerebral cortex and the cerebellum, and is responsible for coordinating voluntary movements. It also helps to form habitual behaviours, things such as walking, riding, and typing. Finally, the cerebral cortex is the most developed part of the brain, and makes up roughly 80% of the brain's volume. All high-level processing takes part in this area of the brain, it is incredible complex and it is discussed in more detail below.
Now the most basic thing that you will notice when looking at the cerebral cortex of the brain is that it is split into 2 parts, these are called the right and left hemispheres. The Right hemisphere controls actions on the left side of the body, and the left hemisphere controls actions on the right hand side of the body. Furthermore, the left side of the brain is associated with logic, words and numbers, two notable areas in the left hemisphere are the Broca's and Wernicke's areas both of which were discussed in the historical timeline. The right side of the brain, to the right hemisphere, is associated with creative pursuits, rhythm, spatial awareness, colour, and imagination. The two sides are joined by a structure called the Corpus Callosum, a band of nerve fibres that manages communication between the right and left hemisphere.
Furthermore, the brain is divided into several lobes. These lobes are the occipital, temporal, parietal, and frontal lobes, these lobes are then further broken down into cortices, and association cortices the cortices include visual, auditory, motor and sensory cortex. Information coming from the environment are registered in the cortices and processed in the association cortices. The Frontal lobe, located obviously at the front of the head just behind the forehead makes up 30 % of the cerebral cortex, it helps in the control of voluntary muscles, intelligence, and personality development and regulation. The most important part of the frontal lobe is the prefrontal cortex, this is the executive portion of the brain involved in planning, reasoning, and organizing thinking. The somatosensory cortex and motor cortex are also located in the frontal lobe. The parietal lobes is located at the top of the head and towards the rear, this lobe has involvement in our ability to give attention to something, our ability to process spatial location, perceiving touch, temperature, and pain, and in our motor control. The sensory association cortex is located in this lobe. The temporal lobe is located on the side of the brain just above our ears. Unsurprisingly it is involved in hearing, language processing, and memory, and the auditory cortex, and auditory association cortex are located in this lobe. Finally, the occipital lobe, which is located at the back of the head, is involved in processing visual information such as shape, colour, and motion. This is also, obviously, where the visual cortex and the visual association cortex is located, although a small part of the visual association cortex is also located in the temporal lobe. There are several pictures below that show the various lobes, and locations of the different cortices, and from several different view points.
Anatomy of the Brain Videos
There are several videos included below that helped to breakdown the sections of the brain and their responsibilities, there is no need to watch all of them, as long as you watch the Pinky and the Brain one at the bottom! Kidding watch at least one of the first three as they do a really good job of providing visuals to accompany the information that has been included above.
And because a discussion about brain anatomy is not complete without a performance by Pinky and the Brain here you go!