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Where Is The Medulla Located In The Brain

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Medulla Oblongata Anatomy Structure

BRAIN: MEDULLA

The medulla may be a portion of the brainstem linking the medulla spinalis and therefore the pons. It extends through the foramen to the amount of the atlas. It is embraced dorsally above the foramen by the cerebral hemispheres.

Medulla extends from the pronto-medullary junction until the plane below the foramen on the brink of 0.5 cm. The spinal cord features a central canal that extends into its lower half to open within the four ventricles at its upper half. The spinal fluid surrounds the medulla from the within and out of doors . The medulla is situated between the 2 lobes of the cerebellum .

Limbic System: Definition Parts Functions And Location

By Olivia Guy-Evans, published April 22, 2021

The limbic system is a collection of structures involved in processing emotion and memory, including the hippocampus, the amygdala, and the hypothalamus.The limbic system is located within the cerebrum of the brain, immediately below the temporal lobes, and buried under the cerebral cortex .

The limbic system was originally called the rhinencephalon because it was thought to be primarily involved with the sense of smell.

Psychologists now recognize that the limbic system serves a lot more functions than previously believed. These structures are known to be involved in the processing and regulating of emotions, the formation and storage of memories, sexual arousal, and learning.

The limbic system is thought to be an important element in the bodyâs response to stress, being highly connected to the endocrine and autonomic nervous systems.

There are two widely accepted structures of the limbic system: the hippocampus and the amygdala. There are differing opinions as to which other structures are included in the system, and what only interacts closely with it.

The nerve cells within the limbic system are structured differently to those in the cerebral cortex. In the cerebral cortex, the cells are mostly neocortical, meaning they are formed into six layers.

Divisions Of The Reticular Formation

Traditionally, the nuclei are divided into three columns:

  • Raphe nuclei
  • Magnocellular red nucleus
  • Parvocellular reticular nucleus
  • 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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    How Is The Medulla Oblongata Related To Breathing

    The ability of chemoreceptors to detect changes in pH is known as pH sensing. Once the chemoreceptors sense your bloods lowered pH, the medulla oblongata triggers you to breathe faster in order to get rid of the harmful excess carbon dioxide and therefore increase the pH of your blood back to normal.

    Medulla Oblongata Blood Supply

    Medulla Oblongata

    There are different arteries that supply blood to medulla conglomerate. Among them, the most important ones are as follows:

    • Anterior Spinal Artery This artery supplies blood to the entire middle section of the medulla oblongata.
    • Vertebral Artery This artery supplies the blood to a region between the other two main arteries, and to the sensory nuclei, solitary nucleus, and fibers.
    • Posterior Inferior Cerebellar Artery It is a major branch of the vertebral artery that supplies blood to the postero-lateral region of the medulla. It is the region where two major sensory tracts function and link. This artery also supplies the blood to a part of the cerebellum.

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    Where Is The Medulla Oblongata Located

    Your medulla oblongata looks like a rounded bulge at the end of your brain stem, or the part of your brain that connects with your spinal cord. It also lies in front of the part of your brain called the cerebellum.

    Your cerebellum looks like a tiny brain joined onto the back of your brain. In fact, its name literally translates to little brain from Latin.

    The hole in your skull that lets your spinal cord pass through is called your foramen magnum. Your medulla oblongata is located at about the same level or slightly above this hole.

    The top of your medulla creates the floor of the fourth ventricle of your brain. Ventricles are cavities filled with cerebral spinal fluid that help provide your brain with nutrients.

    cranial nerves originate on this region.

    Your brain and spine communicate through columns of nerve fibers that run through your medulla called spinal tracts. These tracts can be ascending or descending .

    Each of your spinal tracts carries a specific type of information. For example, your lateral spinothalamic tract carries information related to pain and temperature.

    If part of your medulla becomes damaged, it can lead to an inability to relay a specific type of message between your body and brain. The types of information carried by these spinal tracts include:

    • pain and sensation

    What Is The Hippocampus

    The hippocampus is located in the internal zone of the temporal lobe of the brain and according to the anatomy it is related to the hypothalamus and the amygdala, therefore they work together in the composition of the limbic system.

    The hippocampal formation is a curved and recurve sheet of cortex, located on the medial surface of the temporal lobe.

    Cross sections show that the hippocampal formation is made up of three distinct areas: the dentate gyrus, the hippocampus, and the subiculum.

    In these types of sections, the dentate gyrus and hippocampus are shaped like two interlocking Cs. The subiculum is a transition zone that continues with the hippocampus at one end and the parahippocampal cortex at the other.

    The three components are organized as anterior to posterior bands within the temporal lobe, which together form a cylinder.

    The hippocampus is an important part of the brain since, thanks to research, we know that it has functions related to declarative, non-declarative and long-term memory and to maintain memories depending on what the person experiences emotionally at the moment it is created, what which indicates that it is related to the ability to learn.

    Likewise, it is a brain structure capable of intervening in spatial visual processes, which is why it is considered a necessary area to remember, locate ourselves in space and memorize.

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    Level Of Decussation Of The Medial Lemniscus

    This level marks the sensory decussation occurs of the medial lemniscus. . Purple lines have been used to represent the internal arcuate fibres as they run from the nucleus gracilis and nucleus cuneatus around and anterior to the central gray matter to form the medial lemniscus.

    Lateral to the medial lemniscus, the trigeminal nucleus and spinal tract can once again be seen, as can the spinocerebellar tracts and the lateral spinothalamic tract. Similarly, the posterior structures are much the same at this level.

    Centrally, the hypoglossal nucleus and medial longitudinal fasciculus are seen. Moving laterally, the nucleus ambiguous can be seen. Between this structure and the pyramids is the inferior olivary nucleus.

    Figure 5: Cross-section of Medulla the Decussation of the Medial Lemniscus

    The Ascending And Descending Fiber Pathways Of The Medulla Oblongata

    The Medulla Oblongata and Pons

    Within the medulla oblongata of all mammals studied to date are two major regions of distinct white matter, a medial column and a lateral sheath. The medial column lies between the raphe reticular column and the gigantocellular reticular nucleus . The medial column extends from the dorsal to the ventral aspect of the medulla oblongata for the entire rostrocaudal extent of this segment of the brain stem, except for when the inferior olivary nuclear complex is present, and then the column is split above and below this nuclear complex. This medial column houses several distinctive pathways, such as the medial longitudinal fasciculus, the medial lemniscus, and the pyramidal tract, and several less distinct pathways such as the tectospinal tract. The lateral sheath of white matter courses around the ventral and lateral edges of the medulla oblongata, and within this sheath, the ventral, rostral, and dorsal spinocerebellar, cuneocerebellar, and olivocerebellar tracts are found. These tracts all ultimately merge to form the inferior cerebellar peduncle in the more dorsal and rostral portions of the medulla oblongata.

    Wanda G. Webb PhD, CCC-SLP, in, 2017

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    Sub Fields Of The Amygdala

    The basolateral complex is the largest of the amygdaloid clusters, located roughly within the lateral and middle parts of the amygdala, and includes the lateral and basal nuclei, while the cortical and medial nuclei comprise the cortico-medial amygdaloid group. Interestingly, the basolateral amygdala has been implicated in both mediating the formation of memories related to emotional events and fear extinction through interaction with the prefrontal cortex.

    By Olivia Guy-Evans, published May 09, 2021

    Key Takeaways
    • The amygdala in the limbic system plays a key role in how animals assess and respond to environmental threats and challenges byevaluating the emotional importance of sensory information and prompting an appropriate response.
    • The main job of the amygdala is toregulate emotions, such as fear and aggression.
    • The amygdala is alsoinvolved in tying emotional meaning to our memories.reward processing, and decision-making.
    • When it is stimulatedelectrically, animals show aggressive behavior and when its removed, they no longer show aggressive behavior.

    The amygdala is a complex structure of cells nestled in the middle of the brain, adjacent to the hippocampus .

    The amygdala is primarily involved in the processing of emotions and memories associated with fear. The amygdala is considered to be a part of the limbic system within the brain and is key to how we process strong emotions like fear or pleasure.

    What Is The Gray Matter And White Matter

    Gray and white matter are two different regions of the central nervous system. In the brain, gray matter refers to the darker, outer portion, while white matter describes the lighter, inner section underneath. In the spinal cord, this order is reversed: The white matter is on the outside, and the gray matter sits within.

    Gray matter is primarily composed of neuron somas , and white matter is mostly made of axons wrapped in myelin . The different composition of neuron parts is why the two appear as separate shades on certain scans.

    Each region serves a different role. Gray matter is primarily responsible for processing and interpreting information, while white matter transmits that information to other parts of the nervous system.

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    How To Prevent An Amygdala Hijack

    The first step in preventing an amygdala attack is to identify what triggers it. When you feel the symptoms of amygdala hijack starting, try to pause for a moment to notice what triggered it.

    Anything that causes emotional, physical, or mental stress can be a trigger. There are general categories of stressors that affect everyone to some degree, but specific triggers will be different for everyone.

    Its also helpful to identify other things that trigger the onset of amygdala hijack for you. When you feel threatened or afraid, pause and look for behaviors, bodily changes, or warning signs that are happening at the same time.

    A good way to do this is with mindfulness. This refers to staying in the present and being aware of what youre feeling and thinking, your bodily sensations, and stimuli from your environment.

    Dont try to judge or label the situation as good or bad. Focus only on the current moment, not future tasks or past problems.

    Mindfulness takes practice, but it can be done at almost any time. When youre waiting in the car or going for a walk, take time to focus on what youre thinking and feeling and whats happening around you.

    At first, your mind will quickly start to wander. With more practice, though, itll be easier to stay in the moment.

    Another way to stay present is to focus on your breathing. Focus on the air moving in and out of your nose and how it changes between inhaling and exhaling. Notice which parts of your body move when you take a breath.

    Anatomy Of The Brain And Spine

    Medulla oblongata anatomy, function, location &  medulla ...

    Learn more about the anatomy and the functions of the brain and spine

    The brain and spine are vital to keep the body alive and functioning. Everything we do depends on the messages that are sent from the brain, along the spinal cord and on to the rest of the body.

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    Pons And Medulla Oblongata

    Pons and medulla oblongata together with midbrain and thalamus are part of the brainstem, which is located in the posterior part of the brain. It is a region of transition between central and peripheral nervous system, containing cell nuclei of majority of cranial nerves from which they are emerging to the spinal cord. The pons and medulla developmentally originate from the third vesicle of neural tube . Hox genes orchestrate the segmented organization of spinal cord, pons and medulla and are not expressed in other parts of the brain. Pons facilitates connections between medulla and cerebellum, as well as into the thalamus. Medulla receives inputs from pyramidal tracts originating from the cerebral cortex. These nerves are involved in control of the motoric functions. An important function of pons and medulla is the autonomous control of the body’s vital functions. For example the cardiovascular centers receive sensory inputs from the heart and blood vessels via the vagus nerve and modulates heart rate and blood pressure. A complex network between antagonistic respiratory centers regulates the pattern and rate of the respiratory cycle of inhalation and exhalation.

    Figure 1. Schematic drawing of the human brain, indicating the location of pons and medulla from a coronal perspective or sagittal view.

    ADCYAP1 – parabrachial n.

    Why Is Medulla Oblongata Important

    The medulla oblongata is an integral part of the brain that manages and controls various voluntary and involuntary functions of the brain. It is not possible to live without medulla as it performs a plethora of crucial tasks, like breathing, speaking, eating, blood pressure, and more.

    About Anirudh Agarwal

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    The Structure Of The Brain

    The developing brain goes through many stages. In the embryos of vertebrates, the predecessor to the brain and spinal cord is the neural tube. As the fetus develops, the grooves and folds in the neural tube deepen, giving rise to different layers of the brain. The human brain is split up into three major layers: the hindbrain, the midbrain, and the forebrain.

    The embryonic brain: The layers of the embryonic brain. The telencephalon and diencephalon give rise to the forebrain, while the metencephalon and myelencephalon give rise to the hindbrain.

    External Anatomy Of Medulla Oblongata

    MEDULLA OBLONGATA | NEUROANATOMY

    It is a conically shaped structure that decreases in diameter when extended inferiorly. With dimensions as the 2 cm diameter and 3 cm length, its exact location is between the pons and medulla. The bottom margin of is identified by the origin of the 1st pair of cervical spinal nerves, which rests at the point from where the skull exits through the foramen magnum.

    Posterior Surface of Medulla Oblongata

    There is a midline structure in the posterior median sulcus of the Medulla that extends continuously below to the surface of posterior median sulcus of the spinal cord. From the top, the sulcus ends exactly at the point where the 4th ventricle instigates. Moving laterally from the midline, the fasciculus cuneatus and fasciculus gracilis are identified, which are divided by the posterior intermediate sulcus.

    Anterior Surface of Medulla Oblongata

    The anterior surface of the medulla comprises numerous structures that can be categorized into three broad categories/sulci the Olives, the Cranial Nerves, and the Pyramids.

    The anterior median fissure is located in the midline of the medulla that is continuous along the spinal cords length. But, it is interrupted at some points by the decussation formed from the pyramids. Moving away from the midline, there are two visible sulci the posterolateral sulcus and the ventrolateral sulcus.

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    Diseases/disorders Of Medulla Oblongata

    The Medulla Oblongata may experience various types of damages or injuries that may result in a number of sensory problems. Some of the troubles are numbness, acid reflux, lack of control over the movement of various body organs, difficulty swallowing the food, and even paralysis.

    Medulla is responsible for controlling various autonomic functions in the body, like heart contraction, breathing, and more. So, any damage to it can be fatal to the brain and even result in the death of a person.

    Another major complication that can occur due to damage of Medulla Oblongata is a rare disorder known as a medullar abscess. This is considered as a condition of rapidly progressive numerous cranial nerve clusters and diminished levels of consciousness.

    The multiple system atrophy is a major neurological disorder that damages the nerves cells specified within the brain areas including the medulla oblongata. This ailment can result in loss of control over various autonomic ailments, like coordination, bladder control, and more.

    Cuneate And Gracile Nuclei

    The gracile nucleus and cuneate nucleus, both found in the medulla oblongata, have the same functions but serve different parts of the body. The gracile nucleus receives input from sensory neurons located in the lower body and sends this information to the thalamus. They provide proprioceptive , kinesthetic , and epicritic information.

    The cuneate nucleus has the same function but receives proprioceptive, kinesthetic, and epicritic data from the upper body before sending this data on to the thalamus.

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