Function Of The Medulla Oblongata
The medulla oblongata controls autonomic functions and connects the higher levels of the brain to the spinal cord. It is also responsible for regulating several basic functions of the autonomic nervous system, including:
- Respiration: chemoreceptors
- Reflex centers of vomiting, coughing, sneezing, and swallowing
What Is The Brain
The brain is a complex organ located inside the skull and it manages activity for our nervous system. It is part of the Central Nervous System . It is located in the anterior and superior region of the cranial cavity, and it’s present in all vertebrae. It floats in the cranium in a transparent liquid, called cerebrospinal fluid, which protects it both physically and immunologically.
Is the brain a muscle? Although it is commonly said that it should be trained and exercised like a muscle to prevent atrophy, we must actually be clear that the brain is not a muscle. It is not made up of myocytes, like our muscles, but rather millions of neurons that are interconnected by axons and dendrites. They regulate each and every one of our brain and body functions. From breathing, eating or running, to the ability to reason, to fall in love, or to argue, etc.
The Architecture Of The Brain
The brain is like a committee of experts. All the parts of the brain work together, but each part has its own special properties. The brain can be divided into three basic units: the;forebrain, the;midbrain, and the;hindbrain.
The hindbrain includes the upper part of the spinal cord, the brain stem, and a wrinkled ball of tissue called the cerebellum;. The hindbrain controls the bodys vital functions such as respiration and heart rate. The cerebellum coordinates movement and is involved in learned rote movements. When you play the piano or hit a tennis ball you are activating the cerebellum. The uppermost part of the brainstem is the midbrain, which controls some reflex actions and is part of the circuit involved in the control of eye movements and other voluntary movements. The forebrain is the largest and most highly developed part of the human brain: it consists primarily of the;cerebrum; and the structures hidden beneath it .
When people see pictures of the brain it is usually the cerebrum that they notice. The cerebrum sits at the topmost part of the brain and is the source of intellectual activities. It holds your memories, allows you to plan, enables you to imagine and think. It allows you to recognize friends, read books, and play games.
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How Did We Test Motor Adaptation
To test motor adaptation, we asked everyone to sit in front of the machine shown in Figure 2. Imagine you are one of our participants. The goal is to learn to move the cursor from a start position to a target. You have to learn to do this because the cursor moves in a different direction than your hand. You have sensors on your arm that measure the direction your arm and hand move. Your arm is under the mirror so you cannot see it. All you see displayed on the mirror are circles for the start, the target, and the cursor. The cursor is a small circle with an x in the middle, which gives you visual feedback about your hand position as you move from start to target. First, in the baseline condition, we give you correct visual feedback, meaning that we show your arm the way it actually moves. Second, in the adaptation condition, we give you visual feedback of your arm that is wrong. So, even when your arm is moving up and down, the visual feedback shows your arm moving to the left. You would adapt by gradually moving your arm to the right in order to make the visual feedback go vertical. With practice you learn to adjust the direction of your movement to accurately hit the target, despite the bad feedback.
Look at this movie a couple of times to get a better idea of how adaptation occurs during the beginning, middle and end of the adaptation condition.
Divisions Of The Reticular Formation
Traditionally, the nuclei are divided into three columns:
Sagittal division reveals more morphological distinctions. The raphe nuclei form a ridge in the middle of the reticular formation, and directly to its periphery, there is a division called the medial reticular formation. The medial reticular formation is large, has long ascending and descending fibers, and is surrounded by the lateral reticular formation. The lateral reticular formation is close to the motor nuclei of the cranial nerves and mostly mediates their function. The raphe nuclei is the place of synthesis of the neurotransmitter serotonin, which plays an important role in mood regulation.
The medial reticular formation and lateral reticular formation are two columns of neuronal nuclei with ill-defined boundaries that send projections through the medulla and into the mesencephalon . The nuclei can be differentiated by function, cell type, and projections of efferent or afferent nerves. The magnocellular red nucleus is involved in motor coordination, and the parvocellular nucleus regulates exhalation.
Cross Section of the Pons: A cross section of the lower part of the pons showing the pontine reticular formation labeled as #9.
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Conflict Of Interest Statement
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Original Source Article
Mutha, P. K., Sainburg, R. L., and Haaland, K. Y. 2011. Left parietal regions are critical for adaptive visuomotor control. J. Neurosci. 31:697281. doi: 10.1523/JNEUROSCI.6432-10.2011
Newport, R., Brown, L., Husain, M., Mort, D., and Jackson, S. R. 2006. The role of the posterior parietal lobe in prism adaptation: Failure to adapt to optical prisms in a patient with bilateral damage to posterior parietal cortex. Cortex. 42:7209. doi: 10.1016/S0010-945270410-6
Aflalo, T., Kellis, S., Klaes, C., Lee, B., Shi, Y., Pejsa, K., et al. 2015. Decoding motor imagery from the posterior parietal cortex of a tetraplegic human. Science. 348:90610. doi: 10.1126/science.aaa5417
Does The Brain Stay Alive After A Person Dies
April 2019 marked a milestone for both the initiative and neuroscience research at large: BRAIN Initiative researcher Nenad Sestan, of the Yale School of Medicine, published a report in the journal Nature, revealing that his research team had restored circulation and some cellular functions to pig brains four hours after the animals’ deaths, Live Science previously reported. The results challenged the prevailing view that brain cells are suddenly and irreversibly damaged shortly after the heart stops beating. The researchers did not observe any signs of consciousness in the brains, nor were they trying to; on the contrary, the researchers injected pig brains with chemicals that mimicked blood flow and also blocked neurons from firing. The researchers emphasized that they did not bring the pig brains back to life. They did, however, restore some of their cellular activity.;
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Be Good To Your Brain
So what can you do for your brain? Plenty.
- Eat healthy foods. They contain vitamins and minerals that are important for the nervous system.
- Get a lot of playtime .
- Wear a helmet when you ride your bike or play other sports that require head protection.
- Don’t drink alcohol, take drugs, or use tobacco.
- Use your brain by doing challenging activities, such as puzzles, reading, playing music, making art, or anything else that gives your brain a workout!
Characteristics Of The Human Brain
How much does the human brain weigh? How big is it? How many neurons do we have?
- The cerebral cortex in humans is one of the most evolved and complex among all animal species. It’s not only bigger, but it’s also rolled and folded back over itself, forming grooves and folds which give it that characteristic wrinkled appearance.
- The human encephalon weighs about 1.4-1.5 kilos , and has a volume of about 1130 cc in women and 1260 cc in men.
- It is covered by membranes, called meninges, that protect the skull when it is hit.
- For even more protection, the brain “floats” in cerebrospinal fluid.
- It is estimated that it is made up of more than 100 billion nerve cells, mostly glial cells and neurons.
NEURONS: Are the cells that are specialized in receiving, processing, and transmitting information on intercellular and intracellular levels. This is done through electrochemical signals called action potential. Structurally, neurons have the same cytoplasmic elements and the same genetic information as the rest of the cells in the organism. Neurons are made up of three parts:
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Right Brain Left Brain
The cerebrum is divided into two halves: the right and left hemispheres They are joined by a bundle of fibers called the corpus callosum that transmits messages from one side to the other. Each hemisphere controls the opposite side of the body. If a stroke occurs on the right side of the brain, your left arm or leg may be weak or paralyzed.
Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The right hemisphere controls creativity, spatial ability, artistic, and musical skills. The left hemisphere is dominant in hand use and language in about 92% of people.
How Does The Occipital Lobe Interact With Other Areas Of The Body
No part of the brain is a standalone organ that can function without information from other parts of the body. The occipital lobe is no exception. Although its primary role is to control vision, damage to other brain regions and body parts can inhibit vision. Moreover, some evidence suggests that, when the occipital lobe is damaged, nearby brain regions may be able to compensate for some of its functions. The occipital lobe is heavily dependent on:
- The eyes, particularly the retinas, which take in and process visual information to then be further processed by the occipital lobe.;
- The frontal lobe, which contains the brain’s motor cortex. Without motor skills, the eyes cannot move or take in information from surrounding regions.;
- The temporal lobe, which helps assign meaning to visual information, in addition to encoding it into memories.
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What Happens When The Frontal Lobe Is Damaged
Most people experience some atrophy in the frontal lobe in their senior years, with frontal lobe volume decreasing by .5%-1% each year beginning around age 60. This slow and steady decline accounts for many of the changes, such as mild memory loss and difficulty with finding some words, associated with normal aging. More rapid frontal lobe decline can lead to symptoms of dementia.
The frontal lobe is highly vulnerable to damage for at least two reasons: first, as the last brain region to fully develop, developmental anomaliesincluding child abuse, an insufficiently stimulating environment, drug use, infections, and other factorscan permanently alter its development. Second, the frontal lobe’s home in the front of the forehead renders it highly vulnerable, especially to auto accident-related injuries, violence, and falls. Even relatively minor blows can rattle the brain sufficiently to impede frontal lobe functioning.
The effect of frontal lobe damage is dependent on its location and severity, as well as how quickly it is detected. Children who face serious abuse may live with frontal lobe damage for years, while car accident survivors often get more immediate help. Treatment for frontal lobe injuries typically includes medical and psychological treatment, since the frontal lobe houses the emotional life and personality.
The Cerebrum: Front Part Of The Brain
The largest part of the brain, located in the front, is called the cerebrum. The cerebrum is responsible for:
The cerebrum is made up of the right and left cerebral hemispheres. The hemispheres are connected at the bottom and have a deep groove running between them. In general, the right cerebral hemisphere controls the left side of the body, and the left cerebral hemisphere controls the right. The right side is involved with creativity and artistic abilities. The left side is important for logic and rational thinking.
The cerebral hemispheres are divided into lobes . Each lobe is responsible for a variety of bodily functions. Frontal lobes are involved with personality, speech, and motor development. Temporal lobes are responsible for memory, language and speech function. Parietal lobes are involved with sensation, while the occipital lobes are the primary vision centers.
The surface of the cerebrum appears wrinkled and is made up of deep grooves and bumps or folds . The outer part of the cerebrum is called gray matter and contains nerve cells. The inner part is called white matter and contains connections of nerves.
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Pituitary Gland Controls Growth
The pituitary gland is very small only about the size of a pea! Its job is to produce and release hormones into your body. If your clothes from last year are too small, it’s because your pituitary gland released special hormones that made you grow. This gland is a big player in puberty too. This is the time when boys’ and girls’ bodies go through major changes as they slowly become men and women, all thanks to hormones released by the pituitary gland.
This little gland also plays a role with lots of other hormones, like ones that control the amount of sugars and water in your body.
Brain Structure And Function
The brain has two halves or hemispheres: right and left. The right hemisphere controls the left side of the body, and the left hemisphere controls the right side. In most people, the left hemisphere regulates language and speech, and the right hemisphere controls nonverbal, spatial skills. If the right side of the brain is damaged, movement of the left arm and leg, vision on the left, and/or hearing in the left ear may be affected. Injury to the left side of the brain affects speech and movement on the right side of the body. Each half of the brain is divided into main functional sections, called lobes. There are four lobes in each half of the brain: the Frontal Lobe, Temporal Lobe, Parietal Lobe, and Occipital Lobe. Other important sections of the brain are the Cerebellum and the Brain Stem. Although not usually divided into lobes, the cerebellum and brain stem both have different parts. Each of the brain hemispheres and lobes, cerebellum, and brain stem has specific functions, and they all work together:
This image is from:
Frontal Lobe:;most anterior, right under the forehead; the frontal lobe controls intellectual activities, such as the ability to organize, as well as personality, behavior, and emotional control.
Parietal Lobe:;near the back and top of the head above the ears; the parietal lobe controls the ability to read, write, and understand spatial relationships.
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Major Structures And Functions Of The Brain
Outside the specialized world of neuroanatomy and for most of the uses of daily life, the brain is more or less an abstract entity. We do not experience our brain as an assembly of physical structures ; if we envision it at all, we are likely to see it as a large, rounded walnut, grayish in color.
This schematic image refers mainly to the cerebral cortex, the outermost layer that overlies most of the other brain structures like a fantastically wrinkled tissue wrapped around an orange. The preponderance of the cerebral cortex is actually a recent development in the course of evolution. The cortex contains the physical structures responsible for most of what we call ”brainwork”: cognition, mental imagery, the highly sophisticated processing of visual information, and the ability to produce and understand language. But underneath this layer reside many other specialized structures that are essential for movement, consciousness, sexuality, the action of our five senses, and moreall equally valuable to human existence. Indeed, in strictly biological terms, these structures can claim priority over the cerebral cortex. In the growth of the individual embryo, as well as in evolutionary history, the brain develops roughly from the base of the skull up and outward. The human brain actually has its beginnings, in the four-week-old embryo, as a simple series of bulges at one end of the neural tube.
Ventricles And Cerebrospinal Fluid
Deep in the brain are four open areas with passageways between them. They also open into the central spinal canal and the area beneath arachnoid layer of the meninges.
The ventricles manufacture cerebrospinal fluid, or CSF, a watery fluid that circulates in and around the ventricles and the spinal cord, and between the meninges. CSF surrounds and cushions the spinal cord and brain, washes out waste and impurities, and delivers nutrients.
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Where Is The Brain Located
The brain is located in the top part of the head called the skull. The skull, which is made up of 28 bones, serves the sole purpose of protecting the brain from injury and trauma.
The brain is made up of many parts, but all of these parts are divided into one of two categories. The right hemisphere and the left hemisphere are the two main parts of the brain. The cells that are in the right part of the brain control the left part of the body; the cells that are in the left part of the brain control the right part of the body. These cells are necessary for function of life, and the brain contains enough cells to last throughout a lifetime.
In order for the brain to survive, it must be constantly receiving oxygen. The longest a brain can go without oxygen is around 3 to 5 minutes. After that time period, irreparable injury will occur to the brain. The brain is a medium-sized organ and is about the size of a grapefruit. It ranges from pink to gray in color. It is made up of soft material and adult brains weigh around 3 pounds while children’s brains weigh from about 1 to 2 pounds.