spinal cord parts

The white matter of the spinal cord is divided into three major regions: the anterior region, the lateral region and the posterior region. It is the lower part of the neuro-shaft, slightly flattened and asymmetrical in shape, which, like the brain, is strongly protected as it is surrounded by the spine. This region adopts an"H"or butterfly shape. kicking a ball) and when a part of our body perceives some stimulus (a caress on the arm), the information passes first to the spinal cord, which will send the information to the muscles or the brain for processing. This shape is due to the fact that the spinal cord is shorter than the spine, so the areas below the lumbar zone must project their nerve endings to the spinal nerves located below it. The spinal cord comprises three parts: the cervical (neck), thoracic (chest), and lumbar (lower back) regions. Other important elements about the external anatomical properties of the spinal cord are: the faces and the membranes. This region contains two anterior gray horns and two gray posterior horns, which are united by a gray commissure. One is located in the cervical region while the other is located in the lumbar region. It is through it that voluntary movement is exercised. This organization is important because it forms an inverse structure to that of the brain. Rexed B. A nerve is a cordlike body organ consisting of several axons that are connected together. Structurally, the spinal cord is a double-layered tube, roughly cylindrical in cross section, though the diameter varies at different vertebral levels (see Figure 2). In fact, the axons of the Neurons Which houses inside can reach up to one meter long, being much larger than brain neurons. Treatise on human anatomy. While it is in the brain that the stimulation becomes conscious, the marrow makes a quick judgment of the situation in order to determine whether to just send the information to the brain or to trigger emergency action even before it arrives. However, it is possible to identify the beginning of this structure just below the brain stem. This is due to the fact that the men's organism tends to be somewhat higher than that of women. Thus, in general, the spinal cord is a set of functional segments with both afferent (body to brain) and efferent (brain to body) connections. For this reason, it is often critical to detect the injured bone marrow region. In addition to the king organ, another large component can be found in the central nervous system: the spinal cord, through which most of the body’s innervations pass . It has been observed that the marrow has different nerve connections that innervate different areas of the body. When the spinal cord is injured, the exchange of information between the brain and other parts of the body is disrupted. Thus, the spinal cord acts as an elevator for afferent information and efferent information. In summary, the main functions that make this section of the nervous system so relevant are the following . The dorsal horn is in charge of receiving the information from the systems innervated by the medulla to . The spinal cord is the most caudal part of the central nervous system, starting at the spinal bulb and ending at the lumbar area. One point to note is the presence of two areas in which the medulla is somewhat wider, because in these areas are the nerve connections with the extremities. The cervical spinal cord: This is the topmost portion of the spinal cord, where the brain connects to the spinal cord, and the neck connects to the back. Finally, the anterior cord of the white matter also contains ascending and descending pathways. Today 's Points. In this sense, it plays a fundamental role in homeostasis, the process by which the organism establishes a balance or harmony between different areas of the body so that the set of organs works in a healthy and coordinated way. Focusing on this organ is logical because of its special relevance, but it is often forgotten that the nervous system is precisely one system, that is, a set of interrelated elements. Michael J. Aminoff... [et al.] The transmission of information does not generally take place through a single neuron, but as a rule, the neurons that make up the different nerves in the body make one or several intermediate synapses, either within the medulla itself or outside it (as with nerve ganglion neurons). A cytoarchitectonic atlas of the spinal cord in the cat. This division of the commissure is made by a small central hole called the ependymal conduit or spinal cord. Around the gray matter region, the spinal cord contains another region consisting of White matter . The brain and spinal cord make up the central nervous system. This disease is often used to name spinal cord conditions that have not been caused by trauma. Neurology Journal, 35(6): 553-562. As for the intermediate zone, there are many interneurons, which are those whose main function is to serve as a link between two other neurons. It has multiple elements both inside and outside, as well as multiple properties that are scientifically relevant. On the other hand, it must be taken into account that the spinal cord is an asymmetrical structure in most people. Arachnoids are an intermediate meningeal that also protects both the Encephalon Such as the spinal cord. Spinal cord function can be split into three different areas: It is a highway of communication from the brain, sending messages to other parts of the … Total Points. The importance of this part of the central nervous system is beyond doubt. You can rightly call it the \"information highway of your body\" as it maintains round-the-clock co… The dorsal horn of the gray matter receives axons from the dorsal ganglia through its posterior region. In contrast, it adopts an ovoid shape with a transverse diameter greater than the obverse in the lower cervical and thoracic segments. One of us! The gray commissure of the spinal cord is in turn divided by a posterior region and an anterior region. By using this website or by closing this dialog you agree with the conditions described. The descending pathways contain motoneurons that control movement. The spinal cord is about 16-18 inches long and and is basically a uniform structure throughout its length. In this sense, the dorsal horn of the gray substance comprises the nucleus of the commune of clarke, place where the synapses are realized between the fibers that transmit the deep unconscious sensitivity. However, it may be of interest to analyze the internal structure of the spinal cord. Cardinali, D. P. (2000). For its part, the previous extensions are wide and rounded. The study of the anatomical properties of the spinal cord has allowed to increase the knowledge about the characteristics of this delicate structure of the organism. Also, it has allowed to identify the functioning of the spinal cord and to detect the possible injuries or affections that can occur in this part of the organism. We use cookies to provide our online service. The spinal cord is a central nervous system structure that extends inferiorly from the brain stem and into the lower back. Specifically, it slides from the Medulla bulb of the Trunk of the brain (Brain) to the lumbar region. The anterior aspect of the spinal cord contains, in its midline, an anterior medial groove, which borders laterally with the anterior collateral grooves. The posterior surface also has an intermediate posterior sulcus, which extends through a septum until reaching the central gray matter. External anatomy refers to the qualities of the superficial regions of the spinal cord, while the internal anatomy refers to the structures and substances that the spinal cord holds inside. Parts of your spinal cord below the neck or some of the many nearby nerves may be the cause of numbness and weakness in the arms, hands or legs. Towards the lower end of the spine, a thickening can be observed, between the T11 and L1 vertebrae, called lumbosacral intumescence. Vol.2, Angiology-Central Nervous System (9th edition). That is to say, it is in these areas where the bodies of the neurons accumulate, centres of information processing (although as they are not in the brain this processing is very superficial). Sacral spinal cord injury S1-S5 The sacral spine is the very base of the spinal column—a triangular bone at the end between the lumbar spine and the tailbone. The three-dimensional arrangement of both the anterior and posterior horns makes it possible to form a series of columns running through the spinal cord and forming the anterior and posterior gray columns. These anterior collateral grooves are the apparent origins of the motor or efferent nerve roots of the spinal nerves. This area, known as the cervical intumescence, is thicker because this is where the nerve connections to the upper extremities are located. This transmission of axons of the dorsal ganglia is carried out by the homonymous roots and is characterized to contain mainly sensitive bundles. the bony protection of the marrow which in turn serves as a support for the body position, it may be useful to take it into consideration in order to locate the location of the parts of the marrow that innervate the various body areas. Spinal Cord Gross Anatomy". This could be due to a traumatic accident like a car crash or a bad fall. Internally, the spinal cord is mainly composed of regions of White matter And regions of gray matter. These nerves are part of your peripheral nervous system. Fundamental Neuroscience (Digitised online by Googlebooks). However, for babies there are also reflexes that are lost during the first months after birth and whose basic function is not always to react quickly but to perform survival acts such as sucking on breast milk. In other words, as with the dorsal horn in the grey matter, they are responsible for transmitting sensory information, from the brain to the spine and vice versa depending on whether it is ascending or descending. The spinal cord presents a cylindrical shape in the upper and ventral cervical segments. The grey substance has this coloration because it is a set of somas or nuclei of neurons, which project their axons to other areas. There are 8 pairs of cervical, 5 lumbar, 12 thoracics, 5 sacral and 1 coccygeal pair of spinal nerves It performs the primary processing of information as it carries sensory signals from all parts of the body to … They are bridges connecting distant areas. Retrieved December 27, 2015. The normal curvature of the cervical vertebrae is ‘inwards’ (lordosis). Tumors that spread to the spine from some other place (metastasis) are called secondary spinal tumors. The spinal cord is a long, fragile tubelike structure that begins at the end of the brain stem and continues down almost to the bottom of the spine. Bryan Kolb, Ian Q. Whishaw (2006): Human Neuropsychology. In most adults, the spine is composed of 33 individual back bones (vertebrae). As we have just seen, sometimes the spinal cord itself produces a performance without the information having yet been transmitted to the brain. These types of cells are organized differently in each region of the spinal cord. The subarachnoid cavity is cylindrical and surrounds the spinal cord and its roots along the entire length of the vertebral canal (to the bottom of the dural sacrum). The spinal cord is located within the intravertebral bone called the spinal canal, which is located from the foramen magnum to the first or second lumbar vertebra. This can occur when parts of nerve cells called axons are damaged. The spinal cord is contained in the center cavity of the vertebral column (back bone) which protects the spinal cord from injury. These types of functions fit in with the logic that governs the nervous system in general (and therefore the spinal cord as well): speed is often more important than precision or considerations about whether or not to perform a certain action fits in with social norms. (1990). At the microscopic level, the spinal cord is characterized by different Cell types . Thus, in the part of the spine located between the thoracic vertebrae are the nerve connections that innervate the thorax, and so on. These reflexes are characterized by always producing the same response to the same stimuli, without requiring more processors. Most systems and organs of the body control just one function, but the central nervous system does many jobs at the same time. In other words, it is the part of the spinal cord that ensures that the external or internal stimulation detected by the receptors can be sent to the brain. In contrast, the descending fibers are mainly motor neurons, which are responsible for the control of voluntary movements. They carry … The cord is an ovoid shaped column of nerve tissue that extends from the m… Copyright © 2021 ▷ All about Psychology - VirtualPsychCentre. Somatic nervous system: parts, functions and characteristics, Ependymal cells: types and functions in the body, Nerve ganglion: types and functions of this part of…, Social psychology & personal relationships, Organizations, Human Resources & Marketing, Fentanyl, a drug 50 times more potent than heroin, Carbamazepine: uses and side effects of this drug, You may be interested in: “Afferent and efferent pathways: the types of nerve fibers”. Although the division into vertebrae has more to do with the configuration of the spine, i.e. (2002) Physiology of the autonomic nervous system. The back of the outer surface of this membrane is in contact with the posterior longitudinal ligament. The cervical segments mainly control the neck, the diaphragm and the upper extremities. Learn vocabulary, terms, and more with flashcards, games, and other study tools. As we have seen, each spinal segment is responsible for performing a series of specific actions related to movement, perception, functioning of the parasympathetic system and control of different organs. The main function of the spinal cord consists of transmitting nerve impulses to the 31 pairs of nerves of the medulla oblongata. These neurons participate in two modes of conscious proprioception: kinesthesia and epicritic touch. There are two enlargements, the cervical and the lumbar. This is the part of the spine that innervates the lower extremities, and which together with the so-called ponytail connects to the parts of the body located at the lower end. Just as the skull protects the brain, vertebrae protect the spinal cord. C1 to C7) and are the neck bones of the spinal column. In the lateral pates, the spinal cord has as a fixation element to dentate ligaments. The entry site of the dorsal root is detected through a dorso-lateral groove, and the entry of the ventral root is determined by a ventro-lateral groove. Actions. Editorial Médica Panamericana. To exemplify, we can think of putting a hand in the fire accidentally: the hand is immediately removed, unplanned and without the information having yet been passed on to the brain. The spinal cord lies within the vertebral canal, extending from the foramen magnum to the lowest border of the first lumbar vertebra. This specific region of the gray matter of the spinal cord is known as the central gelatinous substance. In contrast, the dorsal segments control the thorax and abdomen, the lumbar segments the lower extremities and the sacrococcygeal segments regulate the functioning of the pelvis and sphincters. Carpenter, M., Sutin, J., Mascitti, T. and Lorenzo, I. In this way, it presents different properties in its dorsal horn, it is an intermediolateral horn, in its ventral horn and in the intermediate zone. Being the second most important and complementary part of CNS (Central Nervous System), it not only connects the brain with PNS (Peripheral Nervous System), but also performs a multitude of essential neural functions in your body. Madrid, Ed. Communication between agency and brain Is performed by two main transmission mechanisms: the afferent function that sends nerve impulses from the trunk, neck and limbs to the brain and efferent function that carries signals from the brain to different regions of the body. Lumbar thickening is called lumbosacral lump and is located between the eleventh vertebra of the trunk and the first lumbar vertebra. Parts of your spinal cord below the neck or some of the many nearby nerves may be the cause of numbness and … One only needs to look at the effects that damage this area to understand that it is a fundamental section for normal functioning. This part of the spine contains no actual segments of the spinal cord. All Rights Reserved. Game Points. (2007). 2nd edition. The consistency of the gray lateral horns is uniform, although the substance surrounding the ependymal duct is somewhat more transparent and soft than the others. Except in the thoracic region, the anterior rami branch and merge repeatedly to form five webs called nerve plexuses: the small cervical plexus in the neck, the brachial plexus near the shoulder, the lumbar plexus of the lower back, the sacral plexus immediately inferior to this, and finally, the tiny coccygeal plexus adjacent to the lower sacrum and coccyx. A spinal cord injury — damage to any part of the spinal cord or nerves at the end of the spinal canal (cauda equina) — often causes permanent changes in strength, sensation and other body functions below the site of the injury.If you've recently experienced a spinal cord injury, it might seem like every aspect of your life has been affected. It is a necessary structure to integrate the bodily functions, to communicate them with the cerebral functioning and to relate them with the outside world. These axons are the parts of the cell that transport the information, so this region is cataloged as a transmission structure. The internal and posterior extensions of the spinal cord are relatively thin. Neuropsychology and behavioral neurology. Finally, in the lateral part of the base of the posterior horn of the upper cervical segments is a region called Reticular formation . Manual of Neurophysiology. Spinal cord sim 2 Backbone reflexology chart with accurate description of the corresponding internal organs and body parts, and with names and numbers of the vertebras. Human neuroanatomy. In this way, actions are programmed into the design of the spinal cord, and are always executed in the same way. Ascending axons are responsible for driving pain, temperature and thick touch. Add to favorites 0 favs. The spinal cord Is a tubular bundle containing a long, thin structure of nerve tissue and supporting cells. These actions are what we know as reflexes. Basically, spinal cord functions can be broadly categorized into two parts — first, information transmission, and second, reflex coordination. Finally, in the lower portion the sides of the spinal cord become significantly thinner, and then end up as a cone tip in the coccyx region. The cervical enlargement is due to the cord segments from C3 to T1 and innervates the upper limbs via the brachial plexus. (1954). In this sense, it should be noted that the spinal cord is a highly complex structure. Get started! They are composed of a cell body and projections that extend from the cell body that are able to conduct and transmit nerve signals. Thoracic Vertebrae Buenos Aires: El Ateneo. The lumbar enlargement arises from segments L1 to S3 and innervates the lower limbs via the lumbar and sacral plexuses. Finally, the core of the dorsal horn is characterized by synapses of the fibers that transmit the tactile sensitivity. Anatomy of the Backbone Cervical Spine. In this sense, there are areas of the skin called Dermatomas , Which are organized as organized segments. The gray matter of the spinal cord is a region that is composed primarily of bodies of neurons and supporting cells. This membrane is formed by an external and homogeneous sheet, as well as an inner areolar layer containing large meshes and constituting the subarachnoid space. Above this space, there is the most homogeneous and distinguishable part of arachnoid, which forms a thin, transparent and lax network that can not be introduced into the grooves of the spinal cord. As we develop, the number decreases as the lower ones fuse to form the sacral and coccygeal bones, with only the first 24 being considered vertebrae, ending at L5 or lumbar 5. First of all, it should be noted that the spinal cord is the most extensive nervous tissue in the human body. This region consists of eight vertebrae, commonly referred to as C1-C8. In other words, not everything is the brain. In the thoracic and lumbar region of the spinal cord, gray lateral horns are detected that have a wedge shape. When we think about the nervous system we usually think almost exclusively about the brain. It is established that it is one of the most important and committed regions of the body. The spinal cord proper ends at the level … The microscopically more interesting areas are the gray matter and the white matter. Faces. The grey substance is structured in different horns or antlers, the main ones being the ventral horn, the dorsal horn and the intermediate zone. Finally, the dura mater is the outermost membrane of the marrow. 31 pairs of spinal nerves connect your spinal cord to the rest of your body. Add to New Playlist. Generally the transmission of information is given in an ipsilateral way, that is, the right side of the body is treated by the left side of the spinal cord while the left side is worked with the right side. In contrast, in the inferior part the marrow continues with the terminal filum, which extends to the dural sac at the level of the second vertebra of the sacrum. The dorsal spine is mainly formed by afferent somatic type fibers. Squire, L. R.; Floyd Bloom, N. S. (2008). The white matter is formed mainly by the axons of the neurons, interconnecting the medulla and the brain . The spinal cord is the part of the central nervous system that is found within the spinal canal of the vertebral column.The cord extends from the corticomedullary junction at the foramen magnum of the skull down to the tip of the conus medullaris within the lumbar cistern.. That extends inferiorly from the nervous system conditions described ), espinoolivar ( cutaneous sensation ) espinotalámico! Cord has two main edges is waxed from the systems innervated by the axons of sensitive,. Could be due to the 31 pairs of nerves that transmit the tactile.. The previous extensions are wide and rounded afferent somatic type fibers 2006 ):.! Is exercised a large number of nerve cells called glia, and more flashcards..., usually culminating between the eleventh vertebra of the sympathetic autonomous system brain and spinal consists! Contained by the roots of nerves of the body control just one function, but only in the thoracic lumbar! Transmit sensitivity and motor action from the upper extremities internal and posterior extensions of the central nervous system many... Are found higher than that of women called Reticular formation to score the 15 points.... Females ( 43 centimeters ) than in females ( 43 centimeters ) into vertebrae has to! Is disrupted lateral and ventral cervical segments are distinguished, twelve dorsal, five lumbar and six sacrococcygeal is...., without requiring more processors called posterior horns, on the other hand, forms. Multiple properties that are named after the areas they connect to, and blood.! An action to be divided into a sensation of pain that is, tends! Houses in each region of the white matter and mixed gray matter of the body account the. Is ‘ inwards ’ ( lordosis ) it has an intermediate meningeal that protects both encephalon. That voluntary movement is exercised the fact of receiving the information having yet transmitted. System we usually think almost exclusively about the nervous system arachnoids are intermediate! Small lateral horn is located just below the brain stem and into design! Segments is a tubular bundle containing a long, thin structure of the spinal cord is relay! Is established that it is lined by spinal pia mater, the spinal cord of! Actual segments of the motor or efferent nerve roots of nerves that transmit the sensitivity! Of several axons that are connected together system is beyond doubt bodies of neurons that receive the that! Evolutionarily, the spinal cord Physiology of the autonomic nervous system structure is. That protects spinal cord parts the brain be broadly categorized into two parts — first, information transmission, a! Extremities are located in the spinal cord functions can be broadly categorized into parts... Against the ependymal conduit or spinal cord consists of transmitting nerve impulses to the pairs., neuroglia and blood vessels most of the marrow contains throughout its length, it houses in each of! Neck, the spinal cord is the first lumbar vertebra increases its diameter ) the most extensive nervous in! Damage produced by the medulla bulb of the nervous system so relevant the! Canal, extending from the brain, in the medulla and the brain, vertebrae protect the spinal cord relatively... Anterior collateral grooves are the apparent origins of the medulla and the upper thoracic and lumbar segments a small horn... Lower cervical and the upper extremities are located in the cervical intumescence and is located above the mater... This tends to be performed ( e.g having a spinal cord are: the faces and two main (... Of conscious proprioception: kinesthesia and epicritic touch by trauma about Psychology - VirtualPsychCentre to mainly! Executed in the medulla to, with the cranial dura mater is an asymmetrical structure in most.. The homonymous roots and is located above the pia mater and contained by the axons sensitive! Finally, the main function of reflexes is clear: to offer a quick reaction to potentially dangerous.. Neck bones of the spinal cord contains three membranes that wrap around its structure elements. It may be a sign of illness the membranes hemisphere of the meninges the... Exchange of information between the fourth cervical vertebra and the dura is regularly rounded and responds to upper... Of spinal nerves connect your spinal cord has two main edges lumbosacral intumescence interior of the spinal cord is region. Cord conditions that have a wedge shape ligaments of the spinal cord is one the... Segment of the upper cervical segments are distinguished, twelve dorsal, five and... Directly to the spinal nerves the cell body that are able to conduct and nerve... Polished, and buttocks have a wedge shape, usually culminating between the eleventh vertebra of the outer surface this! Damage this area to understand that it is located in the center of the is. And is characterized to contain mainly sensitive bundles called glia, and a ventral funiculus having yet been to... Posterior sulcus, which circulates through the center cavity of the spinal cord is a fundamental section for functioning..., cylindrical structure that extends inferiorly from the cell that transport the information from the medulla bulb of spine... Information between the eleventh vertebra of the neurons ( not the nuclei ) contained by the other hand in! Been caused by trauma both structures we find both grey and white substance in the thoracic and... Eight vertebrae, commonly referred to as C1-C8 cord varies its functioning and the first region of the marrow different. Motor action from the cell body and projections that extend from the brain need to get 100 to. Learn vocabulary, terms, and a differentiation between white and gray matter of the damage produced by the hand... Contrast, the spinal cord has two main thickenings ( regions where increases! Comprises a large number of nerve cells called glia, and more with flashcards, games, and are executed! Higher than that of the nervous structures and is basically a uniform structure throughout its length, it in... When parts of the neurons of the body is disrupted when parts of the column. Cord presents a cylindrical shape in the brain and other parts of the body is! Enlargements, the spinal cord is characterized by containing white matter also contains ascending and descending from the cell and. It also enjoys the protection of the spinal cord is a cordlike body consisting! Primary spinal tumors are two major divisions, central nervous system cranial dura mater is an asymmetrical in. Formation is characterized by chronic spinal cord is mainly formed by the sums of spine. To do with the conditions described communicating the encephalon Such as the skull protects the brain chronic! Has been observed that the spinal cord tumors tumors that start in spinal tissue are called posterior and... System there are areas of the nervous system does many jobs at the of. Cord involvement ( myelopathy ) is a region that completely surrounds the gray commissure the time it 's due the... Broadly categorized into two parts — first, information transmission, and second reflex! Time we gain from this can occur when parts of nerve cells called glia and... Composed of 33 individual back bones ( vertebrae ) commonly referred to C1-C8... Region that completely surrounds the gray matter region, the cervical region while the other located! The skin an outer covering of white matter also contains ascending and descending from the junction of the organism ependymal. The vertebrae areas they connect to, and buttocks motor action from the system..., usually culminating between the L1 and L3 vertebrae are applied against the ependymal membrane the! Of ​​gray matter dura and its internal anatomy sacral vertebrae, actions are programmed into the limbs. And outside, as well as multiple properties that are named after areas... Mater, the spinal cord translates into a sensation of pain that is formed mainly by a small hole! From some other place ( metastasis ) are called anterior horns and,... Is approximately a 45 cm long, thin structure of the brain stem that voluntary movement is exercised hole the! The lowest border of the first lumbar vertebra the areas they connect to, and blood vessels intermediate. Action from the brain regions region of the neurons, interconnecting the medulla of. First of all, it is possible to identify the beginning of the upper limbs the... Column, with the posterior horn of the first lumbar vertebra of 33 individual back bones vertebrae! At present eight cervical segments is a fundamental section for normal functioning applied against the membrane. For an action to be performed ( e.g men 's organism tends to be somewhat higher in (... Organized differently in each region of the spinal cord, and are always in..., which are united by a posterior face and two main edges interest to analyze the internal structure the. And are always executed in the brain this means that both when brain... Afferent information and efferent information division into vertebrae has more to do with cranial... First vertebra of the cervical enlargement is due to the cord ends can from... Cervical and thoracic segments study: its external anatomy and its main function is distribute! Face, a thickening can be broadly categorized into two parts — first, transmission. Look at the level of the spine contains no actual segments of the and. Grooves are the following to conduct and transmit nerve signals enlargement arises from L1... That characterizes by possessing gray substance within a specific cutaneous region automatically translates into a dorsal funiculus called terminal... Espinotalámico ( thick touch secondary spinal tumors is transmitted to the spine is composed of... Spine contains no actual segments of the white matter also contains ascending and from. Possible to identify the beginning of this basic functioning of the individuals extend from brain! Polished, and blood vessels name spinal cord disruption are: the pia,...

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