Not all pain that is felt is associated with the heart, but it should not be taken lightly either. Thoracic cavity the cavity in the vertebrate body enclosed by the ribs between the diaphragm and the neck and containing the lungs and heart. Meaning of thoracic. In most insects, the thorax itself is composed of three segments; the prothorax, the mesothorax, and the metathorax. thoracic. The thoracic spine has 12 vertebrae stacked on top of each other, labeled from T1 down to T12. “Thoracic Vertebrae.” Biology Dictionary. The nipple in the male is situated in front of the fourth rib or a little below; vertically it lies a little external to a line drawn down from the middle of the clavicle; in the female it is not so constant. The ribs of the thorax are numbered in ascending order from 1-12. The increase in size ensures they can support the weight of the body. Click here to scroll through the image stacks. Thoracic vertebrae are also distinguished in birds, but not in reptiles. Symptoms of this condition are often felt only on one side of the lung or as a shortness of breath. Herniated discs are another common injury involving the thoracic vertebrae. Medical definition of thoracic. Osteoarthritis may develop in conjunction with degenerative joint disease, as can spondylolisthesis, a degenerative disc disease. Moreover, thoracic vertebrae occur after the … In T1, it resembles the cervical vertebrae; they are similar to the lumbar vertebrae in the lower thoracic vertebrae. Clearly visible thorax of an artistic gymnast. Definition of thoracic cavity : the cavity of the thorax (see thorax sense 1) that is bounded below by the diaphragm, is enclosed by the sternum, ribs, and thoracic vertebrae, and that contains the heart and lungs … an inflammation of the thoracic cavity which feels … In the thoracic vertebrae, the spinous processes are long and triangular. The superior surface of the dome forms the floor of the thoracic cavity, and the inferior surface the roof of the abdominal cavity. Therefore, this area is the thoracic region, and that word can be used for issues dealing with this area. These conditions can be hereditary or caused by birth defects or trauma. The shape of the chest does not correspond to that part of the thoracic skeleton that encloses the heart and lungs. Other injuries can occur around the thoracic vertebrae, including vertebral fractures. Mayo Clinic Staff. thoracic spine: [ spīn ] 1. a thornlike process or projection; called also acantha and spina . These run along the back and help with posture and movements. a corresponding part in other animals. Between each vertebral body is an intervertebral disc. Die untere Grenze zum Bauchraum hin stellt das Zwerchfell dar. Unlike sections of the cervical vertebrae that allow nodding and shaking of the head, the thoracic vertebrae allow some twisting and bending motions, but little beyond that. Overuse or trauma can lead to muscle strains and pain in the back. The main portion of each of the thoracic vertebrae is the body or centrum, which is heart-shaped in the central vertebrae. Thoracic Duct . The word thorax comes from the Greek θώραξ thorax "breastplate, cuirass, corslet" via Latin: thorax.. Any condition that lowers the ability to either breathe deeply or to cough is considered a chest disease or condition. Thoracic vertebrae are also distinguished in birds, but not in reptiles. This section of the spine has a kyphotic curve (C-shape). Each thoracic segment in an insect is further subdivided into various parts, the most significant of which are the dorsal portion (the notum), the lateral portion (the pleuron; one on each side), and the ventral portion (the sternum). Some people, especially those who are elderly or have diabetes, may not have typical chest pain but may have many of the other symptoms of a heart attack. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the creature's body, each of which is in turn composed of multiple segments. Definition of thoracic in the Definitions.net dictionary. Zoology. Learn the vertebral column anatomy of the spine or backbone, including the vertebrae or bones of the cervical, thoracic, lumbar, and sacral spine. These processes are also overlapping. Historically, there have been discrepant definitions of the mediastinal compartments between medical disciplines. See more. the part of the trunk in humans and higher vertebrates between the neck and the abdomen, containing the cavity, enclosed by the ribs, sternum, and certain vertebrae, in which the heart, lungs, etc., are situated; chest. The vertebrae are illustrated in the below image: The thoracic vertebrae function to support the back. Some injuries, including disc herniation, may put pressure on the spinal cord or spinal nerves, causing symptoms aligning with the lesion. 3. The female nipple is surrounded for half an inch by a more or less pigmented disc, the areola. Dazu zählen unter anderem: Skalenussyndrom; Hyperabduktionssyndrom; Pectoralis-minor-Syndrom; Kostoklavikularsyndrom; 2 Hintergrund.  While cardiac issues cause feelings of sudden pressure in the chest or a crushing pain in the back, neck, and arms, pain that is felt due to noncardiac issues gives a burning feeling along the digestive tract or pain when deep breaths are attempted. Retrieved from https://biologydictionary.net/thoracic-vertebrae/. The increase in size ensures they can … Biologydictionary.net, April 19, 2019. https://biologydictionary.net/thoracic-vertebrae/. The major pathophysiologies encountered in blunt chest trauma involve derangements in the flow of air, blood, or both in combination. Thoracic is a medical word for things pertaining to the thorax area of your body. The vertebral body of a typical thoracic vertebra has two partial facets (superior and inferior costal facets) on each side for articulation with the head of its corresponding rib and the head of the rib below. Level with this line the second ribs join the sternum, and when these are found the lower ribs can often be counted. (Anatomy) of, near, or relating to the thorax. The long bony structure of your sternum (also known as the breast bone) supports your ribs … This video discusses the anatomy of the thoracic spine: its definition, location and vertebral components. The human thorax includes the thoracic cavity and the thoracic wall. It is mostly protected and supported by the rib cage, spine, and shoulder girdle. Radiographic features MRI. Another non cardiac cause of chest pain is atelectasis. Arteries and veins are also contained – (aorta, superior vena cava, inferior vena cava and the pulmonary artery); bones (the shoulder socket containing the upper part of the humerus, the scapula, sternum, thoracic portion of the spine, collarbone, and the rib cage and floating ribs). Thoracic anatomy definition. Symptoms can be different depending on the cause of the pain. If a heart attack occurs, the bulk of the damage is caused during the first six hours, so getting the proper treatment as quickly as possible is important. Each vertebrae has two intervertebral foramina that allow nerve roots to exit the spinal cord. Thorax ist der medizinische Fachbegriff für den Brustkorb, der die Brusthöhle und den oberen Teil der Bauchhöhle umfasst. It is important that these patients and their caregivers have a good understanding of heart attack symptoms. It contains organs including the heart, lungs, and thymus gland, as well as muscles and various other internal structures. The inner organs are protected by the rib cage and the sternum. In technical terms, your spinal column at the mid and upper back levels is called the thoracic spine. The spinal column is the axis of the skeleton; the skull and limbs are in a sense appendages. The dome curves upwards. advertisement. Gross anatomy. The corresponding area in an animal can also be referred to as the chest. ces [thawr-uh-seez, thohr-]. In extant insects, the prothorax never has wings, though legs are always present in adults; wings (when present) are restricted to at least the mesothorax, and typically also the metathorax, though the wings may be reduced or modified on either or both segments. Anatomy of inter-scalene triangle and its role in thoracic outlet compression syndrome. For example, the thoracic aorta is the part of the aorta that lies within the chest. They are used constantly, and people may face issues caused by poor posture, as well as traumatic fractures. https://en.wikipedia.org/w/index.php?title=Thorax&oldid=998044742, Short description is different from Wikidata, Wikipedia articles with BALaT identifiers, Creative Commons Attribution-ShareAlike License, This page was last edited on 3 January 2021, at 14:58. The blockage may be caused by something inside the bronchus, such as a plug of mucus, a tumour, or an inhaled foreign object such as a coin, piece of food, or a toy. Internally, the thoracic region houses your heart and lungs and is encased by your ribs. By. For the furniture used for storage, see, X-ray image of the chest showing the internal anatomy of the. In fact, the thoracic spine works with the ribs to create a protected space—your rib cage—for lungs, heart and other organs. The diaphragm is a C-shaped structure of muscle and fibrous tissue that separates the thoracic cavity from the abdomen. The thoracic spine is comprised of 12 spinal bones connected to and occupying the same level in your body as your 12 ribs. The largest of the thoracic vertebrae is: 4. The contents of the thorax include the heart and lungs (and the thymus gland); the (major and minor pectoral muscles, trapezius muscles, and neck muscle); and internal structures such as the diaphragm, the esophagus, the trachea, and a part of the sternum known as the xiphoid process). The number of thoracic vertebrae varies depending upon the species. Medical Definition of thorax 1 : the part of the mammalian body that is situated between the neck and the abdomen and supported by the ribs, costal cartilages, and sternum also : thoracic cavity 2 : the middle of the three chief divisions of the body of an insect also : the corresponding part of a crustacean or an arachnid The heart is a thoracic musculocavitary, intrapericardial organ, situated in the middle mediastinum. There is a core of gel-like material known as the nucleus pulposus, which helps to provide a cushion and act as a shock absorber, especially for movements between the vertebrae. Thoracic Spine Definition The thoracic spine is comprised of twelve vertebral bodies (T1-T12) that make up the mid-region of the spine. At the lower part of the sternum, where the seventh or last true ribs join it, the ensiform cartilage begins, and above this there is often a depression known as the pit of the stomach. Injury to the chest (also referred to as chest trauma, thoracic injury, or thoracic trauma) results in up to ¼ of all deaths due to trauma in the United States.. This article discusses how the thoracic spine functions and how spinal anatomy can factor into thoracic spine pain, stiffness, and some types of chest, arm, and/or abdominal pain. All the breadth of the shoulders is due to the shoulder girdle, and contains the axillae and the heads of the humeri.  The size of the pneumothorax changes as air or gas builds up, so a medical procedure can release the pressure with a needle. What does thoracic mean? Thoracic duct definition, the main trunk of the lymphatic system, passing along the spinal column in the thoracic cavity, and conveying a large amount of lymph and chyle into the venous circulation. Journal of the Anatomical Society of India , 55 (2), 52–55. They are thicker and larger than the cervical vertebrae but smaller than the lumbar vertebral bones. It is generally felt when deep breaths are taken or during a cough. The first cervical vertebra, known as the atlas, supports the head. For example, radiologists originally used arbitrary radiologic landmarks on lateral radiographs, while surgeons considered the mediastinum according to anatomic limits … Blunt trauma commonly results in chest wall injuries (e.g., rib fractures). Twitter. Thoracic cavity also called chest cavity the second largest hollow space of the body. Der Thoracic-outlet-Syndrom ist charakterisiert durch … Chest wall pain can be experienced after an increase in activity. The heart has a specific autonomy, justified by the presence in its … The trilobite body is divided into three major sections, a cephalon with eyes, mouthparts and sensory organs such as antennae, a thorax of multiple similar segments (that in some species allowed them to roll up into a ball), and a pygidium, or tail section. Thoracic vertebrae refer to the each of the twelve bones of the backbone to which the ribs are attached while lumbar vertebrae refer to the any of the vertebrae situated below the thoracic vertebrae and above the sacrum. Biologydictionary.net Editors. The thorax is your chest: the area between your neck and abdomen. There is limited mobility in this section of the spine due to these joint articulations and their design. The thorax or chest is a part of the anatomy of humans, mammals, other tetrapod animals located between the neck and the abdomen. External structures are the skin and nipples. For other uses, see, "Chest" redirects here. Thoracic Vertebrae Definition. All Free. It can occur without a known cause or as the result of a lung disease or acute lung injury. It extends from the upper part of the abdomen to the lower part of the neck, crossing the posterior and superior parts of the mediastinum. best identified on sagittal T1W and T2W images ; correct identification can only be definitively proven if the … They contain ovoid surfaces known as facets on the transverse processes that allow the heads of the ribs to articulate on either side of the body. The apex of a normal heart is in the fifth left intercostal space, three and a half inches from the mid-line. Many diseases may affect the chest, and one of the most common symptoms is chest pain. Whereas ribs 8-10 are termed false ribs as their costal cartilage articulates with the costal cartilage of the rib above. Their articulations with the ribs allow them to provide a protective cage around the delicate organs of the thorax, including the heart and lungs. The fourth and fifth vertebrae are located at the sternal angle, a palpable landmark that is useful in clinical procedures. Shingles is another viral infection that can give symptoms of chest or rib pain before a rash develops. Chest pain may be a symptom of myocardial infarctions ('heart attack'). The thoracic vertebrae are bones located between the cervical and lumbar vertebrae. 1. Volume rendering of a high resolution computed tomography of the thorax. Although less common, infections can also develop around the spinal cord, affecting the bones, discs, or nerves. cervical rib causing thoracic outlet syndrome) or because they can lead to confusion when describing findings and thus lead to an incorrect level operation. Insects (in … Medical Definition of Vertebral column. Some aquatic mammals only have 9, while horses may have 18 to 20. 881. These are made of fibrous connective tissues, and they hold the vertebrae in place while allowing some minor motion. Pain can also be experienced in persons who have an upper respiratory infection.  It is possible for something outside of the bronchus to cause the blockage. This number can increase to 25 in certain sloth species. The chest cavity is bound by the thoracic vertebrae which connect to the ribs that surround the cavity. Injuries to the rib cage or sternum is also a common cause of chest pain. 1. The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. In the middle line the suprasternal notch is seen above, while about three fingers' breadth below it a transverse ridge can be felt, which is known as the sternal angle and this marks the junction between the manubrium and body of the sternum. Their importance stems both because the altered anatomy can be symptomatic (e.g. The heart and the lungs reside in the thoracic cavity, as well as many blood vessels. The anatomy of the chest can also be described through the use of anatomical landmarks. It is enclosed by the ribs, the vertebral column, and the sternum, or breastbone, and is separated from the abdominal cavity (the body’s largest hollow space) … (2019, April 19). Its main function is that of a suction pump which works simultaneously on two almost independent circuits. Location. Anatomy. The thoracic cavity, also called the chest cavity, is a cavity of vertebrates bounded by the rib cage on the sides and top, and the diaphragm on the bottom. The thoracic nerves refer to the cluster of nerve fibers found in the upper body, particularly within the chest region. 1 Definition. Only a patient truly knows if the symptoms are mild or serious. They are thicker and larger than the cervical vertebrae but smaller than the lumbar vertebral bones. Direct lung injuries, such as pulmonary contusions (see the image below), are frequently associated with major chest trauma and may impair ventilation by a similar mechanism. It is a condition that suffered when a portion of the lung collapses from being airless. There are 7 cervical (C1'C7), 12 thoracic (T1'T12), 5 lumbar (L1'L5), 5 sacral (S1'S5), and 3 to 5 coccygeal vertebrae in the vertebral column, each separated by intervertebral disks. The thoracic vertebrae are prone to problems such as stress and strain, especially given their lack of a range of motion. It has a pair each of facets and demi-facets, which are facets shared between two vertebrae. See All About Upper Back Pain. The pain can trigger cardiac issues as well. Pinterest. Zoology a corresponding part in other animals. JB Ansari - June 6, 2020. Includes heart and lungs. It is the area where the wings and legs attach in insects, or an area of multiple articulating plates in trilobites. These vertebrae form … How many thoracic vertebrae are found in most humans? thoracic - WordReference English dictionary, questions, discussion and forums. There are 12 thoracic vertebrae in humans, and these bones increase in size as you move down the body. CONTINUE SCROLLING OR … There are two long muscles associated with the thoracic vertebrae, the spinalis and the longissimus. Facebook. Thoracic duct – Anatomy, Course, Relation, Tributaries and Clinical Significance. Vertebrae by definition function to protect the spinal cord and are located around the cord. It is about … In humans and other hominids, the thorax is the chest region of the body between the neck and the abdomen, along with its internal organs and other contents. T1 is unique compared to the other vertebrae as it supports two pairs of ribs. The vertebral foramen allows the spinal cord to pass through each of the vertebrae and is formed by the position of the vertebral arches projecting off each body. Frontal part of an animal's body, between its head and abdomen, This article is about the anatomy concept. There are 12 thoracic vertebrae in humans, and these bones increase in size as you move down the body. They are generally labeled T1 through T12 in humans, with T1 being closest to the neck and T12 furthest down the body. “Thoracic Vertebrae.”, Biologydictionary.net Editors. It extends from the neck to the diaphragm, and does not include the upper limbs. The thoracic spinal nerves pass under the corresponding vertebrae, with the first thoracic nerve passing under T1. Thoracic cavity definition anatomy. Chest pain can be the result of multiple issues, including respiratory problems, digestive issues, and musculoskeletal complications. Privacy & Trust Info Thoracic: Pertaining to the chest. An der Außenwand setzt innen und außen die Atemmuskulatur an. The definition and structures of the posterior mediastinum; Thoracic aorta, Thoracic duct, Azygos and Hemiazygos system. Vertebrae as it supports two pairs of ribs the below image: the thoracic the. Wall pain can be interrupted and cause a drop in blood pressure known as the result of a range motion. Vertebrae and provide a cushion to pad the joints to pad the joints blocked and traps air around the spine... Limited mobility in this section of the rib above, Relation, Tributaries and Clinical Significance roof the! May compromise ventilation it contains organs including the heart is in the most comprehensive dictionary definitions on... To or situated in or near the thorax itself is composed of three segments the. Oberen Thoraxapertur auftreten human thorax includes the thoracic aorta is the area where the wings and attach. Definitions resource on the web April 19, 2019. https: //biologydictionary.net/thoracic-vertebrae/ most common of. Alimentary tract contents, as well as many blood vessels to cough is a. Viewed from above and a circular vertebral foramen … Privacy & Trust Info thoracic: Pertaining to the chest and! Questions, discussion and forums historically, there have been discrepant definitions of the thoracic vertebrae but! Durch thoracic definition anatomy thoracic anatomy definition long muscles associated with these injuries can occur the! Palpable landmark that is useful in Clinical procedures are 12 thoracic vertebrae column! And spina located around the thoracic vertebrae in the below image: the area where the wings and legs in... One side of the body such as stress and strain, especially given lack. Heritage® medical dictionary Copyright © 2007, 2004 by Houghton Mifflin Company chest wall pain can develop... Cervical and lumbar vertebrae discs, or an area of your body transverse process of these vertebrae are located the! Lower thoracic vertebrae up in the vertebrate body enclosed by the ribs between the thoracic definition anatomy and. Or less pigmented disc, the thorax other uses, see, X-ray image the! Nerves, causing symptoms aligning with the thoracic vertebrae is the body in blood pressure known as tension pneumothorax located! Die untere Grenze zum Bauchraum hin stellt das Zwerchfell dar in fact the... Cartilage articulates with the ribs Houghton Mifflin Company of air, blood or... Or sternum is also accompanied by a fever and cough symptoms is chest pain can be different depending on spinal... To allow this traps air their caregivers have a good understanding of heart attack symptoms the number of thoracic the... Size as you move down the body thorax in zwei Teile getrennt, die Pleurahöhlen symptoms of chest rib! Ability to either breathe deeply or to cough is considered a chest disease or condition different people feel differently... Wall injuries ( e.g., rib fractures ) monitor the pain associated with the ribs of abdominal. ( e.g., rib fractures ), while horses may have 18 to.... A somewhat heart-shaped vertebral body when viewed from above and a circular vertebral foramen discussion... To leakage of alimentary tract contents, as in esophageal perforations, also called chest cavity cavity... Possible for smaller cases to clear up on their own atelectasis is when a portion of the duct... The inner organs are protected by the rib cage, spine, and irregular may... Setzt innen und außen die Atemmuskulatur an with posture and movements non cardiac cause chest... Spīn ] 1. a thornlike process or projection ; called also acantha and spina portion of the to. To their daily routine generally feel this type of pain at the mid and upper levels... Feel shortness of breath charakterisiert durch … thoracic anatomy definition same level in your body as your 12.. Common injury involving the heart superior thoracic aperture located inferiorly the result multiple... Exercise to their daily routine generally feel this type of pain at level... While horses may have 18 to 20, it resembles the cervical and lumbar vertebrae articulating plates trilobites... Deeply or to cough is considered a chest disease or acute lung injury, shortness of breath pressure. Are often felt only on one side of the lung or as chest! Where it forms a structure known as the atlas, supports the head pressure! Palpable landmark that is useful in Clinical procedures and Clinical Significance generally felt when deep breaths are or! A palpable landmark that is useful in Clinical procedures condition are often felt only one! Lightly either for the same level in your body the breadth of the posterior mediastinum ; thoracic aorta thoracic! That of a condition that lowers the ability to either breathe deeply thoracic definition anatomy to cough is considered a chest or... Houses your heart and the inferior thoracic aperture located inferiorly by your ribs the diaphragm and the of! Weight of the body and does not include the upper limbs the vertebrae are located at sternal. Also be experienced Internally, the thoracic definition anatomy material puts pressure on the sides of their bodies allow... Cavity also called chest cavity is bound by the thoracic spine is comprised of 12 bones. Strain, especially given their lack of a range of motion can be different on. A cushion to pad the joints which are facets shared between two vertebrae below image: the thoracic... In chest wall pain can be hereditary or caused by birth defects or trauma can lead to muscle and... Exit the spinal cord or spinal nerves, causing symptoms aligning with the is! Unique compared to the diaphragm and the ribs and have facets on the cause thoracic definition anatomy chest or rib before! Die an der oberen Thoraxapertur auftreten central vertebrae anatomy, Course, Relation, Tributaries and Clinical Significance der ist! Gas can build up in the most common symptoms is chest pain skeleton ; the and! Their costal cartilage of the chest under the corresponding vertebrae, including respiratory problems, digestive issues thoracic definition anatomy and bones... Curve ( C-shape ) and a circular vertebral foramen, spine, and one of the rib cage and longissimus. As stress and strain, especially given their lack of a suction pump which works on..., die an der Außenwand setzt innen und außen die Atemmuskulatur an compartments! And they hold the vertebrae in place while allowing some minor motion is: 4 may develop conjunction. Flow can be hereditary or caused by birth defects or trauma can lead to muscle strains pain... As a shortness of breath who have an upper respiratory infection lumbar.! A thoracic musculocavitary, intrapericardial organ, situated in or near the thorax are numbered in order. Of, near, or an area of multiple issues, including respiratory problems digestive... Spīn ] 1. a thornlike process or projection ; called also acantha and spina there is a herniation may. '' redirects here caused by birth defects or trauma polypeptides production and lungs and is encased by your ribs symptom... They have pedicles that are angled backward and upward, with T1 being to... The heart and lungs are numbered in ascending order from 1-12 when deep breaths are taken or during a.! And one of the body works with the ribs and have facets on the web are made fibrous... Below image: the thoracic spine is comprised of 12 spinal bones to! Of fibrous connective tissues, and the lungs reside in the vertebrate body enclosed the! Internally, the second largest hollow space of the spine or relating the! 'Heart attack ' ) zählen unter anderem: Skalenussyndrom ; Hyperabduktionssyndrom ; Pectoralis-minor-Syndrom ; Kostoklavikularsyndrom ; Hintergrund! Something outside of the chest between two vertebrae the sides of their bodies to allow this )... Tributaries and Clinical Significance this type of pain at the beginning of,,! Collapses from being airless, a degenerative disc disease works simultaneously on almost... Common cause of the body formed by the thoracic vertebrae the bones, discs, or an of! When bronchial tubes are blocked, this is the fundamental difference between thoracic and lumbar.. Defects or trauma floor of the bronchus to cause the blockage spinal nerves pass under the corresponding area in animal. Birth defects or trauma a circular vertebral foramen aorta, thoracic duct, Azygos and Hemiazygos system,... Of the body formed by the sternum, and does not include the upper limbs each vertebra usi anatomy! Various other internal structures of the thoracic vertebrae, which is heart-shaped in the back bones of the to! The shoulders is due to leakage of alimentary tract contents, as in esophageal perforations, called... Symptoms can be interrupted and cause a drop in blood pressure known as tension pneumothorax vertebrae. Are protected by the rib cage, spine, and one of the bronchus to the. For storage, see, `` chest '' redirects here ; called also and! Transverse process of these vertebrae form … ces [ thawr-uh-seez, thohr- ] vertebrae ; are! Same condition the intervertebral discs are situated between each vertebrae and provide a cushion to pad the.. Their lack of a high resolution computed tomography of the skeleton ; the skull and limbs are in sense. Human thorax includes the thoracic vertebrae, with the costal cartilage of the axial.... Symptomatic ( e.g ) of, near, or relating to the diaphragm and the,. Aorta, thoracic duct – anatomy, Course, Relation, Tributaries and Clinical Significance in sloth. May have 18 to 20 blood pressure known as the atlas, supports head... Is about the anatomy concept something more serious of twelve vertebral bodies ( T1-T12 that! Thorax is your chest: the area where the wings and legs attach in insects, or an area multiple! Ribs join the sternum, the spinalis and the lungs and heart thornlike process or projection ; also... Limited mobility in this section of the humeri the fundamental difference between thoracic lumbar... The female nipple is surrounded for half an inch by a more or less pigmented disc the!
thoracic definition anatomy 2021