Which structure regulates intellectual function

The hypothalamus is a small structure in the middle of the brain below the thalamus. It plays a part in controlling body temperature, hormone secretion, blood pressure, emotions, appetite and sleep patterns. The pituitary gland is a small, pea-sized organ in the centre of the brain. It receives messages from the hypothalamus and releases hormones that control the thyroid and adrenal gland, as well as growth and physical and sexual development.

The pineal gland is a very small gland in the third ventricle of the brain. It produces the hormone melatonin, which influences sleeping and waking patterns and sexual development. There are 12 pairs of cranial nerves that perform specific functions in the head and neck, including giving us our sense of smell, sight vision , hearing, taste, speech, feeling in the face and movement of the muscles in the face, eyes and tongue. One pair of nerves starts in specialized cells in the roof of the nose and another pair starts in the retina of the eye.

The other 10 pairs start in the brain stem. The blood-brain barrier BBB is a specialized system of cells lining blood vessels in the brain. The BBB prevents most substances in the blood from passing into the brain and helps maintain a constant environment so the nerve cells in the brain can work properly.

The BBB is made up of very small blood vessels capillaries that are lined with thin, flat endothelial cells. In other parts of the body, endothelial cells have small spaces between them that allow substances to move in and out of the capillary so they can reach other cells and tissues. In the brain, the endothelial cells are packed tightly together so substances cannot pass out of the bloodstream into the brain.

The spine is made up of 26 bones divided into 5 sections. These bones surround and protect the spinal cord. This includes 24 vertebrae divided into cervical, thoracic and lumbar regions , the sacrum and the coccyx. Cervical region — These are 7 vertebrae at the top of the spine that run from the base of the skull to the lowest part of the neck.

Thoracic region — These are 12 vertebrae that run from the shoulders to the middle of the back. Lumbar region — These are 5 vertebrae that run from the middle of the back to the hips. Sacrum — This is a large section of fused vertebrae at the base of the spine. Coccyx tail bone — This is a small, thin section of fused vertebrae at the end of the spine.

Disc — A layer of cartilage found between the vertebrae. Olds and Milner discovered these reward centres accidentally after they had momentarily stimulated the hypothalamus of a rat. The researchers noticed that after being stimulated, the rat continued to move to the exact spot in its cage where the stimulation had occurred, as if it were trying to re-create the circumstances surrounding its original experience.

Upon further research into these reward centres, Olds discovered that animals would do almost anything to re-create enjoyable stimulation, including crossing a painful electrified grid to receive it. In one experiment a rat was given the opportunity to electrically stimulate its own hypothalamus by pressing a pedal. The rat enjoyed the experience so much that it pressed the pedal more than 7, times per hour until it collapsed from sheer exhaustion.

The hippocampus is important in storing information in long-term memory. If the hippocampus is damaged, a person cannot build new memories, living instead in a strange world where everything he or she experiences just fades away, even while older memories from the time before the damage are untouched. All animals have adapted to their environments by developing abilities that help them survive.

Some animals have hard shells, others run extremely fast, and some have acute hearing. Human beings do not have any of these particular characteristics, but we do have one big advantage over other animals — we are very, very smart.

But this does not really work. Despite these comparisons, elephants do not seem 10 times smarter than whales, and humans definitely seem smarter than mice. The key to the advanced intelligence of humans is not found in the size of our brains. What sets humans apart from other animals is our larger cerebral cortex — the outer bark-like layer of our brain that allows us to so successfully use language, acquire complex skills, create tools, and live in social groups Gibson, In humans, the cerebral cortex is wrinkled and folded, rather than smooth as it is in most other animals.

This creates a much greater surface area and size, and allows increased capacities for learning, remembering, and thinking. The folding of the cerebral cortex is referred to as corticalization. The cortex contains about 20 billion nerve cells and trillion synaptic connections de Courten-Myers, Supporting all these neurons are billions more glial cells glia , cells that surround and link to the neurons, protecting them, providing them with nutrients, and absorbing unused neurotransmitters.

The glia come in different forms and have different functions. For instance, the myelin sheath surrounding the axon of many neurons is a type of glial cell. The glia are essential partners of neurons, without which the neurons could not survive or function Miller, The cerebral cortex is divided into two hemispheres , and each hemisphere is divided into four lobes , each separated by folds known as fissures.

If we look at the cortex starting at the front of the brain and moving over the top see Figure 4. Following the frontal lobe is the parietal lobe, which extends from the middle to the back of the skull and which is responsible primarily for processing information about touch.

Then comes the occipital lobe at the very back of the skull, which processes visual information. Finally, in front of the occipital lobe pretty much between the ears is the temporal lobe , responsible primarily for hearing and language. Furthermore, they discovered an important and unexpected principle of brain activity.

This finding follows from a general principle about how the brain is structured, called contralateral control, meaning the brain is wired such that in most cases the left hemisphere receives sensations from and controls the right side of the body, and vice versa.

Fritsch and Hitzig also found that the movement that followed the brain stimulation only occurred when they stimulated a specific arch-shaped region that runs across the top of the brain from ear to ear, just at the front of the parietal lobe see Figure 4. Fritsch and Hitzig had discovered the motor cortex , the part of the cortex that controls and executes movements of the body by sending signals to the cerebellum and the spinal cord. More recent research has mapped the motor cortex even more fully, by providing mild electronic stimulation to different areas of the motor cortex in fully conscious patients while observing their bodily responses because the brain has no sensory receptors, these patients feel no pain.

As you can see in Figure 4. Again, the more sensitive the body region, the more area is dedicated to it in the sensory cortex. Our sensitive lips, for example, occupy a large area in the sensory cortex, as do our fingers and genitals. Other areas of the cortex process other types of sensory information. The visual cortex is the area located in the occipital lobe at the very back of the brain that processes visual information.

The temporal lobe, located on the lower side of each hemisphere, contains the auditory cortex , which is responsible for hearing and language. The temporal lobe also processes some visual information, providing us with the ability to name the objects around us Martin, The motor and sensory areas of the cortex account for a relatively small part of the total cortex.

The remainder of the cortex is made up of association areas in which sensory and motor information is combined and associated with our stored knowledge. These association areas are the places in the brain that are responsible for most of the things that make human beings seem human.

The association areas are involved in higher mental functions, such as learning, thinking, planning, judging, moral reflecting, figuring, and spatial reasoning. The control of some specific bodily functions, such as movement, vision, and hearing, is performed in specified areas of the cortex, and if these areas are damaged, the individual will likely lose the ability to perform the corresponding function.

On the other hand, the brain is not divided up in an entirely rigid way. As a result, the brain constantly creates new neural communication routes and rewires existing ones. Neuroplasticity enables us to learn and remember new things and adjust to new experiences. The principles of neuroplasticity help us understand how our brains develop to reflect our experiences. For instance, accomplished musicians have a larger auditory cortex compared with the general population Bengtsson et al.

These observations reflect the changes in the brain that follow our experiences. Plasticity is also observed when there is damage to the brain or to parts of the body that are represented in the motor and sensory cortexes. When a tumour in the left hemisphere of the brain impairs language, the right hemisphere will begin to compensate to help the person recover the ability to speak Thiel et al.

And if a person loses a finger, the area of the sensory cortex that previously received information from the missing finger will begin to receive input from adjacent fingers, causing the remaining digits to become more sensitive to touch Fox, These new neurons originate deep in the brain and may then migrate to other brain areas, where they form new connections with other neurons Gould, We have seen that the left hemisphere of the brain primarily senses and controls the motor movements on the right side of the body, and vice versa.

This fact provides an interesting way to study brain lateralization — the idea that the left and the right hemispheres of the brain are specialized to perform different functions. Gazzaniga, Bogen, and Sperry studied a patient, known as W. In this surgery, the region that normally connects the two halves of the brain and supports communication between the hemispheres , known as the corpus callosum , is severed. As a result, the patient essentially becomes a person with two separate brains.

Because the left and right hemispheres are separated, each hemisphere develops a mind of its own, with its own sensations, concepts, and motivations Gazzaniga, In their research, Gazzaniga and his colleagues tested the ability of W.

The researchers had W. The cerebellum is attached to the dorsal side of the pons. The cerebellum is a separate region of the brain located behind the medulla oblongata and pons. It is attached to the rest of the brain by three stalks called pedunculi , and coordinates skeletal muscles to produce smooth, graceful motions.

It also receives output from the cerebral cortex about where these body parts should be. After processing this information, the cerebellum sends motor impulses from the brain stem to the skeletal muscles so that they can move. The main function of the cerebellum is this muscle coordination. However, it is also responsible for balance and posture, and it assists us when we are learning a new motor skill, such as playing a sport or musical instrument.

Recent research shows that apart from motor functions the cerebellum also has some role in emotional sensitivity. The midbrain is located between the hindbrain and forebrain, but it is actually part of the brain stem. It displays the same basic functional composition found in the spinal cord and the hindbrain. Ventral areas control motor function and convey motor information from the cerebral cortex.

Dorsal regions of the midbrain are involved in sensory information circuits. The substantia nigra, a part of the brain that plays a role in reward, addiction, and movement due to its high levels of dopaminergic neurons is located in the midbrain. The diencephalon is the region of the embryonic vertebrate neural tube that gives rise to posterior forebrain structures.

In adults, the diencephalon appears at the upper end of the brain stem, situated between the cerebrum and the brain stem. It is home to the limbic system, which is considered the seat of emotion in the human brain.

The diencephalon is made up of four distinct components: the thalamus, the subthalamus, the hypothalamus, and the epithalamus. The thalamus is part of the limbic system. It consists of two lobes of grey matter along the bottom of the cerebral cortex. Lesions of, or stimulation to, the thalamus are associated with changes in emotional reactivity. However, the importance of this structure on the regulation of emotional behavior is not due to the activity of the thalamus itself, but to the connections between the thalamus and other limbic-system structures.

Limbic system, brain stem, and spinal cord : An image of the brain showing the limbic system in relation to the brain stem and spinal cord. The hypothalamus is a small part of the brain located just below the thalamus. Lesions of the hypothalamus interfere with motivated behaviors like sexuality, combativeness, and hunger. The hypothalamus also plays a role in emotion: parts of the hypothalamus seem to be involved in pleasure and rage, while the central part is linked to aversion, displeasure, and a tendency towards uncontrollable and loud laughing.

When external stimuli are presented for example, a dangerous stimuli , the hypothalamus sends signals to other limbic areas to trigger feeling states in response to the stimuli in this case, fear. Hypothalamus : An image of the brain showing the location of the hypothalamus. The spinal cord is a tail-like structure embedded in the vertebral canal of the spine. The adult spinal cord is about 40 cm long and weighs approximately 30 g.

The spinal cord is attached to the underside of the medulla oblongata, and is organized to serve four distinct tasks:. The cerebral cortex is the outermost layered structure of the brain and controls higher brain functions such as information processing. The cerebral cortex, the largest part of the mammalian brain, is the wrinkly gray outer covering of the cerebrum.

The cerebral cortex is considered the ultimate control and information-processing center in the brain. The cortex is made of layers of neurons with many inputs; these cortical neurons function like mini microprocessors or logic gates. It contains glial cells, which guide neural connections, provide nutrients and myelin to neurons, and absorb extra ions and neurotransmitters. The cortex is divided into four different lobes the parietal, occipital, temporal, and frontal lobes , each with a different specific function.

Lobes of the brain : A diagram of the brain identifying the different lobes by color. Counterclockwise from bottom: It contains the parietal lobe green , the occipital lobe red , the temporal lobe yellow , and the frontal lobe blue. The cortex is wrinkly in appearance. Evolutionary constraints on skull size brought about this development; it allowed for the cortex to become larger without our brains and therefore craniums becoming disadvantageously large. Current research suggests that both of these may be at least partially true, but the degree to which they correlate is not clear.

While there are variations from person to person in their sulci and gyri, the brain has been studied enough to identify patterns. One notable sulcus is the central sulcus, or the wrinkle dividing the parietal lobe from the frontal lobe. Beneath the cerebral cortex is the cerebrum, which serves as the main thought and control center of the brain.

It is the seat of higher-level thought like emotions and decision making as opposed to lower-level thought like balance, movement, and reflexes. The cerebrum is composed of gray and white matter. Gray matter is the mass of all the cell bodies, dendrites, and synapses of neurons interlaced with one another, while white matter consists of the long, myelin-coated axons of those neurons connecting masses of gray matter to each other.

Grey matter and white matter : A sagittal cross-section of a human brain showing the distinct layers of grey matter the darker outer layer and white matter the lighter inner layer in the cerebrum. The brain is divided into two hemispheres and four lobes, each of which specializes in a different function. The brain is divided into two halves, called hemispheres. There is evidence that each brain hemisphere has its own distinct functions, a phenomenon referred to as lateralization.

The left hemisphere appears to dominate the functions of speech, language processing and comprehension, and logical reasoning, while the right is more dominant in spatial tasks like vision-independent object recognition such as identifying an object by touch or another nonvisual sense.

However, it is easy to exaggerate the differences between the functions of the left and right hemispheres; both hemispheres are involved with most processes. Additionally, neuroplasticity the ability of a brain to adapt to experience enables the brain to compensate for damage to one hemisphere by taking on extra functions in the other half, especially in young brains. The two hemispheres communicate with one another through the corpus callosum.

The midbrain is often considered the smallest region of the brain. It acts as a sort of relay station for auditory and visual information. The midbrain controls many important functions such as the visual and auditory systems as well as eye movement. Portions of the midbrain called the red nucleus and the substantia nigra are involved in the control of body movement. The darkly pigmented substantia nigra contains a large number of dopamine-producing neurons.

The medulla is located directly above the spinal cord in the lower part of the brain stem and controls many vital autonomic functions such as heart rate, breathing, and blood pressure.

The pons connects the cerebral cortex to the medulla and to the cerebellum and serves a number of important functions. It plays a role in several autonomic processes, such as stimulating breathing and controlling sleep cycles.

The cerebellum is comprised of small lobes and serves a number of important functions. Although there is no totally agreed-upon list of the structures that make up the limbic system, four of the main regions include:. The hypothalamus is a grouping of nuclei that lie along the base of the brain near the pituitary gland.

The hypothalamus connects with many other regions of the brain and is responsible for controlling hunger, thirst, emotions , body temperature regulation, and circadian rhythms. The hypothalamus also controls the pituitary gland by secreting hormones.

This gives the hypothalamus a great deal of control over many body functions. The amygdala is a cluster of nuclei located close to the base of the brain. It is primarily involved in functions including memory, emotion, and the body's fight-or-flight response. The structure processes external stimuli and then relays that information to the hippocampus, which can then prompt a response to deal with outside threats.

Located above the brainstem, the thalamus processes and transmits movement and sensory information. It is essentially a relay station, taking in sensory information and then passing it on to the cerebral cortex. The cerebral cortex also sends information to the thalamus, which then sends this information to other systems. The hippocampus is a structure located in the temporal lobe. It is important in memory and learning and is sometimes considered to be part of the limbic system because it plays an important part in the control of emotional responses.

It plays a role in the body's fight-or-flight response and in the recall and regulation of emotional memories. The brain can also be affected by a number of conditions and by damage. According to the National Institute of Neurological Disorders and Stroke, there are more than types of neurological diseases.

Some conditions that can affect the brain and its function include:. By studying the brain and learning more about its anatomy and function, researchers are able to develop new treatments and preventative strategies for conditions that affect the brain.

You can't change your genetics or some other risk factors. But it's important to take steps to help protect the health of your brain. Research suggests that regular physical activity is essential for brain health.

For example, that exercise can help delay brain aging as well as degenerative diseases such as Alzheimer's, diabetes, and multiple sclerosis. It is also associated with improvements in cognitive abilities and memory. Similarly, a nutritious, balanced diet that includes omega-3 fatty acids, vitamins, and antioxidants is important for brain function as well as overall health. It's also essential to protect your brain from injury by, for example, wearing a helmet when participating in physical activities that pose a risk for collision or falls, and always wearing a seatbelt when driving or riding in a car.

Sleep can also play a pivotal role in brain health and mental well-being. Studies have found that sleep can actually play a role in the development and maintenance of some psychiatric conditions including anxiety, depression, and bipolar disorder. Evidence also suggests that staying mentally engaged can also play an important role in protecting your brain from some degenerative conditions. Activities that may help include learning new things and staying socially active.