The Location Of The Substantia Nigra And The Vta
A further complication resulting from the severe cephalic flexion of the neuraxis at the level of the midbrain is a misunderstanding of the segmental location of the substantia nigra and the VTA. It is widely assumed that both of these structures lie within the midbrain, but in fact only a caudal portion of both the substantia nigra and the VTA can be found in the compressed true ventral midbrain , and the rostral parts of the substantia nigra and VTA lie in the diencephalon, across its prosomeres 1, 2, and 3. The caudalmost parts of these dopaminergic populations lie in the isthmus . The overall result is that only about one quarter of the substantia nigra and VTA can be said to belong to the midbrain, and modern literature refers to a mesodiencephalic SN/VTA complex. Some differential gene expression has been observed along these four parts of the SN/VTA, suggesting that each segmental module possibly manifests subtle differential properties .
S And Functions Of The Brain Stem
The brain stem can be divided into three major parts, each of which handles the bulk of some specific set of functions.
The midbrain is the highest and first part of the brain stem. The midbrain consists of three general parts. The tectum is the highest part of the brain stem and forms the tissue that connects the brain stem to the lowest parts of the cerebellum. The main role of the tectum is to regulate reflex activity in response to visual and auditory stimuli and engage in basic level visuoauditory processing.
The tegmentum is the second part of the midbrain and is much larger than the tectum. The tegmentum is a complex of synaptic neurons that connect to both the cerebellum above and the pons below. The tegmentum primarily plays a role in homeostasis and motor reflex action. Many of the bodys nervous tracts pass through the tegmentum so it serves as a major relay to conduct motor signals to the rest of the brain.
Lastly, the ventral tegmentum is located near the midline of the midbrain. the ventral tegmentum shares connections with the forebrain and is the largest dopamine-producing area in the brain. As such, the ventral tegmentum is heavily involved in the neural reward system.
Lastly, there is a great deal of evidence that implicates the pons as the brain region that generates REM sleep cycles.
What Is The Corpus Callosum
The cerebrum’s inner core houses the brain’s “white matter.” The major part of the inner core is known as the corpus callosum. The corpus callosum is a thick tract of fibrous nerves that serve as a kind of switchboard enabling the brain’s hemispheres to communicate with one another. Whereas the cerebral cortex is the cerebrum’s outer layer made up of gray matter, and is responsible for thinking, motor function and information processing the corpus callosum is the cerebrum’s inner core, made up of white matter, with four parts of nerve tracts connecting to different parts of the hemispheres.
Home of the white matter: corpus callosum./Life Sciences Database/Wikimedia Commons
The corpus callosum’s nerve fibers are coated with myelin. This fatty substance helps increase the transmission of information between the next part of the cerebrum: the two hemispheres.
What Are The Four Nuclei Of The Cerebellum
As the three lobes take in information from the cerebrum, spinal cord and body, the cerebellum also has a way of sending out information. This is done through what are called nucleia bundle or neurons embedded deep in the cerebellum’s white matter.
Rounding out cerebellum’s composition are the four nuclei that pass information between the cerebrum and the body. These nuclei are: dentate, emboliform, globose, and fastcgi. They receive on the body and give information from the cerebellum through Purkinje cells and mossy fibers.
Life Sciences Database/Wikimedia Commons
The final section of the brain is a mass of tissue and nerves called the brain stem. Located underneath the cerebrum and cerebellum, the brain stem connects the brain to the spinal cord. All information that goes from the brain to the body , must pass through the brain stem to reach its destination. The brain stem accounts for the remaining 5% of the brain’s mass, and is , the oldest part of the brain. The brain stem is responsible for regulating the heart and lungs, communications between the brain and the peripheral nervous system , our sleep cycle, and coordinating reflexes.
The brain stem plugs the brain into the rest of the body through the spinal cord .
Which Is The Brain Stem
Your brainstem is the bottom, stalklike portion of your brain. It connects your brain to your spinal cord. Your brainstem sends messages to the rest of your body to regulate balance, breathing, heart rate and more. Sudden injuries, and brain or heart conditions may affect how your brainstem works.Jun 21, 2021
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What Is An Oblongata
Medulla oblongata, also called medulla, the lowest part of the brain and the lowest portion of the brainstem. … The medulla oblongata plays a critical role in transmitting signals between the spinal cord and the higher parts of the brain and in controlling autonomic activities, such as heartbeat and respiration.
What Is Brainstem Death
Brainstem death means a person has no brainstem functions. It occurs when something permanently damages the brainstem or cuts off the brains blood or oxygen supply.
Because the brainstem controls essential life functions, someone who experiences brainstem death cannot regain consciousness. They need artificial life support to remain alive. This condition is sometimes also called brain death.
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The Linear Nucleusan Extension Of The Lateral Reticular Nucleus
In 2009, Fu et al., showed that a dorsal extension of the lateral reticular nucleus, which they named the linear nucleus, projects to the cerebellum. This nucleus appears to be a constant feature of mammalian brains. However, it should be recognized that the first description of the nucleus, and the original application of the name linear, must be credited to Cajal , who described it as forming a part of the lateral reticular nucleus. A segmental analysis of this nucleus in the mouse has recently been completed by .
S Of The Brain: Structures Anatomy And Functions
The human brain is one of the largest and most complex organs in the body. It controls your emotions, thoughts, speech, memory, creativity, breathes, movement, and stores information from the outside world. This article discusses the different parts of the brain and the function of each structure.
The brain is a 3-pound organ that contains more than 100 billion neurons and many specialized areas. There are 3 main parts of the brain include the cerebrum, cerebellum, and brain stem. The Cerebrum can also be divided into 4 lobes: frontal lobes, parietal lobes, temporal lobes, and occipital lobes. The brain stem consists of three major parts: Midbrain, Pons, and Medulla oblongata. Although each structure has a distinct function, they work together to control all functions of the body.
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What Is The Brain Stem And What Does It Do
The brain stem is the oldest, most primitive part of the human brain. This tube-shaped region is about three inches long and made up entirely out of nervous tissue.
The brain stem forms a bridge between the brain and the spinal cord and plays the most vital role of all. Despite its small size, the brain stem is one of the most important parts of your brain and body.
Its responsible for many vital functions. Breathing, swallowing, and digestion only to name a few. Your whole body and the rest of your brain all rely on a healthy brain stem function.
To get an understanding of how important its role really is, consider this analogy
A flower and all its petals, small branches and leaves represent your brain, body and its vital organs. The main stem and roots represent your brain stem. If you cut the flower off of the main stem, it will start to shrivel away and die.
Thats how important it is!
In this article, we will take a closer look at the structure, function, and importance of the brain stem.
The Interfascicular Trigeminal Nucleus
This nucleus had previously been named the tensor tympani part of the motor trigeminal nucleus in rodent brain atlases , because it was thought to be a subset of small motor neurons of the motor trigeminal nucleus innervating the tensor tympani muscle. However, the neurons forming the interfascicular trigeminal nucleus were labeled following injection of retrograde tracer in the cerebellum, and the labeled neurons were found to be choline acetyltransferase negative, proving that they are not motor neurons . In addition, the cells of the interfascicular trigeminal nucleus are strongly labeled in mice via Wnt1Cre and Atoh1CreER lineage fate mappinga feature common to the major precerebellar nuclei that arise from the rhombic lip and that issue mossy fibers .
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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!
Where Is The Location Of The Brain Stem
Located just above the spinal cord, the brain stem connects the spinal cord to the cerebellum part of the brain. Its connection is made up of three pairs of nerve bundles known as cerebellar peduncles.
In addition, the brain stem also serves as the connection between the cerebrum and the cerebellum, two of the four main regions of the brain.
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The Cell Structure Of The Brain
The brain is made up of two types of cells: neurons and glial cells, also known as neuroglia or glia. The neuron is responsible for sending and receiving nerve impulses or signals. Glial cells are non-neuronal cells that provide support and nutrition, maintain homeostasis, form myelin and facilitate signal transmission in the nervous system. In the human brain, glial cells outnumber neurons by about 50 to one. Glial cells are the most common cells found in primary brain tumors.
When a person is diagnosed with a brain tumor, a biopsy may be done, in which tissue is removed from the tumor for identification purposes by a pathologist. Pathologists identify the type of cells that are present in this brain tissue, and brain tumors are named based on this association. The type of brain tumor and cells involved impact patient prognosis and treatment.
Problems With Traditional Brain Stem Nomenclature
When the traditional nomenclature of the brain stem is tested against the new understanding of brain stem organization based on developmental gene expression, five major areas of misinterpretation become apparent. These are the true identity of the pons, the existence of the isthmus, the true definition of the midbrain without diencephalic and hindbrain additions, the location of the substantia nigra and VTA , and the segmental origin of the cerebellum.
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The True Identity Of The Pons
The primary problem with the use of the word pons is that its historical meaning attaches to the voluminous formation seen on the ventral surface of the human brain. The basilar pontine formation is exceptionally large in humans , and this has led to misinterpretation over its true topological position. In many mammals, the basilar pontine nuclei and the reticulotegmental nucleus aggregate at the ventral part of rhombomeres 3 and 4, and the pontine bulge is restricted to the ventral surface of these two rhombomeres. An interesting developmental feature of the basilar pons is that the neurons that form the pontine nuclei develop in the rhombic lip of rhombomeres 6 and 7 and then migrate tangentially under the pia to their final location in rhombomeres 3 and 4 .
On the other hand, human anatomy textbooks uniformly state that the pons extends from the caudal end of the midbrain to the beginning of the medulla oblongata just rostral to the exit of the vestibulocochlear and abducens nerves. The differential growth of the basilar pons in humans hides much of the rostral prepontine hindbrain , on one side, and the part of the retropontine hindbrain containing the abducens nucleus, superior olive, and facial nucleus, on the other .
The Cerebellum’s Left And Right Hemispheres
The cerebellum also has two hemispheres: the left cerebellar hemisphere and the right cerebellar hemisphere. Just as the longitudinal fissure divides the cerebrum’s hemispheres, the “vermis” separates the cerebellum’s hemispheres.
Cerebellar hemispheres seen from front and back / The Database Center for Life Science/Wikimedia Commons
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Can You Recover From A Brainstem Injury
A brainstem injury can have severe effects because the brainstem controls so many of your bodys most basic functions. But people do recover from some types of brainstem injuries.
Its important to get care right away if you suspect a brainstem injury. The sooner you get care, the more likely your healthcare providers can reduce the damage. You may need rehabilitation and other special care after a brainstem injury.
What Are The Functions Of The 3 Main Parts Of The Brain
The brain has three main parts:
- The cerebrum fills up most of your skull. It is involved in remembering, problem solving, thinking, and feeling.
- The cerebellum sits at the back of your head, under the cerebrum. It controls coordination and balance.
- The brain stem sits beneath your cerebrum in front of your cerebellum.
What are the major parts of the brain stem?
The brainstem includes the midbrain, the pons and the medulla.
How has our brain evolved?
Human brain size evolved most rapidly during a time of dramatic climate change. Larger, more complex brains enabled early humans of this time period to interact with each other and with their surroundings in new and different ways.
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How Can I Keep My Brainstem Healthy
Some lifestyle changes can keep your entire brain healthier. To keep your mind sharp and support your brain health, you may:
- Drink alcohol only in moderation.
- Eat a diet full of fruits, vegetables, whole grains, healthy fats and lean protein.
- Exercise regularly.
A strong social network has also been linked with brain health. Healthy relationships can help lower your blood pressure, decrease stress and increase your life span.
A note from Cleveland Clinic
Your brainstem is the bottom part of your brain. It looks like a stalk that connects the rest of your brain to your spinal cord. Your brainstem sends signals from your brain to the rest of your body. It controls many subconscious body functions, like breathing and maintaining your heart rate. Brain tumors, strokes or traumatic brain injuries may damage your brainstem. You can lower your risk of these conditions by adopting healthy habits like exercising and eating a nutritious diet.
Last reviewed by a Cleveland Clinic medical professional on 06/21/2021.
What Is The Brain And Why Does It Matter
The brain is a three-pound organ that serves as headquarters for our bodies. Without it, we wouldn’t be able to process information, move our limbs, or even breathe. Together with the spinal cord, brain structure and function helps control the central nervous systemthe main part of two that make up the human nervous system. The human nervous system is responsible for helping us think, breathe, move, react and feel.
Like any good command center, there is a structure to the brain and its operations that help it carry out its basic functions.
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Main Parts Of The 3 Pound Human Brain
The brain is a powerful and vital organ that is essential tobeing alive. With that said, it would not hurt to have knowledge of the mainparts of the brain and their functions. Basically, the brain has 3 parts: the cerebrum, the cerebellum and the brainstem. Each of these parts provides different functions for the brain, and wecannot survive without them.
1. Cerebrum: also called cortex is by far the largestportion of the brain, and weighs about two pounds. For the record, the entirebrain weighs three pounds. The cerebrum is home to billions and billions ofneurons. These neurons control virtually everything we do. It controls ourmovements, thoughts and even our senses. Since the cerebrum has so many functions,if its damaged, there are many different consequences.
The cerebrum consists of four different lobes that controlall of our movements. The four lobes include: the frontal lobe, parietal lobe,temporal lobe and the occipital lobe. The frontal lobe controls our emotions,judging and planning skills. The parietal lobe controls our senses such astaste, temperature and pain. The temporal lobe controls our auditory processesand hearing. The occipital lobe controls our vision.
Lastly, the cerebrum consists of two layers: the cerebralcortex, which controls our coordination and personality, and the white matterof the brain, which allows the brain to communicate.
The Existence Of The Isthmus
The isthmus, understood as a distinct hindbrain segment separating the midbrain from the other hindbrain rhombomeres, was already identified morphologically by His , but was later arbitrarily ascribed to the midbrain in conventional neuroanatomical texts. In contemporary works, the isthmic territory is defined early in development by the selective expression of Fgf8 . The mature progeny of the isthmus have been demonstrated in a recent Cre Fgf8 lineage study . Within the isthmic territory so defined, lie the trochlear nucleus , the parabigeminal nucleus, the microcellular tegmental nucleus, and the decussation of the superior cerebellar peduncle . The isthmus therefore lies between the caudal midbrain and rhombomere 1 .
Most neuroanatomical texts used by health science students do not comment on the presence of the isthmus at all . A few make note of the organizing role of the isthmic region in the development of the midbrain/hindbrain junction, but do not acknowledge its presence in the mature brain . A small number of textbooks recognize the presence of the isthmus in both the developing and developed brain but mistakenly describe it as forming the caudal part of the midbrain . The modern concept of the isthmus concept establishes a new caudal boundary for the midbrain region, which coincides with the caudal expression limit of the gene Otx2 in all vertebrates .