viewers good day to all of you so this is dr bk for you with one more new region which i am starting today so i think we have successfully completed the limbs and from this session onwards i will be dealing with thorax so we all know that from the limbs that is the appendages of the body now we are moving to the trunk region so the upper part of the trunk is actually called as the thorax and you all know that thorax is a very important region because it lodges or houses the vital organs of the respiration and the circulation that is the lungs and the heart okay now so as i told you the diaphragm is the one which is a musculotendinous partition which divides the trunk of your body into an upper half and the lower half so below the trunk what you have is the abdomen and above the trunk what you see is the thorax now whether it is the thorax or the abdomen it is first a silent body cavity okay we are all silomates that means we possess a syllabic cavity now because of the development of this syllabic cavity we are actually three dimensional in nature otherwise what happens is during the early stages we you would have noticed in your embryology classes that it is a bilaminar germ disc then what happens it is a trilaminar germ risk and only when the foldings takes place what happens is we become three dimensional and during this foldings what happens we have a large body cavity the primitive body cavity is the syllabic cavity so this syllabic cavity the cells lining this cavity what happens they are responsible for the formation of your pleura and the peritoneum okay in the same way even the pericardium so that is how what happens is the body cavities are actually developed and slowly what happens is these organs they invaginate into your body cavities from behind and they come and occupy their respective places so that the development we will be seeing it later in the appropriate classes now if you basically or generally look at the thoracic cavity it is somewhat conical in shape but the apex is not very pointed it is like a truncated core and then you have the base if you take a section and you look at the section of the thorax it is somewhat ready form or kidney shape okay so that is because you know in the midline the bodies of the vertebra are present but in case of the childrens and infants the cross section is going to be more or less circular because the developmental process is still going on and what happens is the ribs have not completely developed angulation of the ribs has not been formed properly the vertebral column is also under the process of development and because of that what happens is in the infants and in units what happens is the if you take a cross section of the thorax it is almost circular and not really form like in the case of adults so inside the thoracic cavity you know it is subdivided into the pleural cavities you have two pleural cavities on either side and in the midline you have the pericardial cavity which lodges your heart okay so now we all know how vital these organs are necessary so naturally we need some protection for these organs and that is in the form of a rigid wall it is not only very rigid or tough but it should also be pliable that means it should be too flexible to some extent to allow expansion or movements because you know our lungs expand during normal breathing and also during forced breathing it expands considerably same way the heart also you know the heart beats so naturally some amount of movement is appreciated in the heart and breathing movements of the lungs the wall which is built around it it is should not only give protection so that is why it is a rigid work but it should also allow some flexibility or movement for these organs and that is why the thoracic wall is actually not only it is osteo cartilaginous but is it is also elastic fibrous and also muscular so it is not only made up of rigid structures like your boats and cartilages in between the bones it is filled with muscles and then of course there are also membranes which is bridging the muscles and the bones and the cartilages so that is why dhoni is an osteocardial genius as well as an elastic wall cover thoracic wall so if you remove all these membranes and the muscles and only the bones and cartilages then you call it as the thoracic cage or the ribcage it is a thoracic cage or ribcage so now you are able to see the anterior aspect and also the posterior aspect of the ribcage so it is mainly made up of the ribs so that is called as rib cage or you can call it also as the thoracic cage in front it is articulating with the sternum and behind you see the vertebral column which is made up of the thoracic vertebra okay so the ribs are all bars of bones in between the bones you have the spaces which are actually called as the intercostal spaces so these spaces are filled with soft tissues mainly your intercostal muscles and membrane are also present and it has their corresponding vessels and nerves so your ribcage is mainly made up of began by the 12 thoracic vertebra so they are actually stacked are arranged one below the other starting from the first thoracic to the 12th thoracic vertebra then posteriorly exactly the midline little laterally if you come you have the posterior part of the ribs okay then what happens is the ribs articulate ventrally with the sternum so anterior you have the sternum and not directly but in the form of coastal cartilages so it is actually the cartilage which is bridging the sternum and the ribs and they all form a joints which is actually the chondro sternal joints cornrow refers to the cartilage so that is why it is actually called as the chondrosternal joints they are primary cartilaginous joints so they are not secondary or synovial joints they are actually primary cartilaginous joints the first rib actually ossifies by 25 years of age the first chordal sternum joint okay it gets ossified then anteriorly what you are able to see here is the sternum which consists of three parts the mani brain sternum the body of the sternum and then what you see here is the zifister okay then if you look at the anterior surface body of the vertebra it is concave somewhat scooped out anteriorly not very conspicuous but you can look out and not only that these vertebra are actually concave ventral so the curvatures what you see is the curvatures it is in the thoracic part it is concave ventrally and it is the primary curvature which is seen during the bug itself the secondary curvatures which is going to get developed in the cervical region which is going to be convex anteriorly and same way one more convex anteriorly is going to takes place at the lumbar region okay so these two develop at the later stage by first year you can see the cervical curvatures developing due to the weight bearing once the head is supported by the neck and once the child starts walking the lumbar curvature develops because of weight bearing so these two are secondary curvatures which are developed the primary curvature is actually concave ventrally which is seen in the thoracic part of the vertebral column so mainly the ribcage is formed by the thoracic vertebra ribs and the sternum in front ribs means naturally it is the ribs with the costal cartilage posteriorly the ribs are directly articulating with the thoracic vertebra there is no any sort of cartilage posteriorly so these are all the thoracic vertebrae you are able to see and they are the spines of the thoracic vertebra so as i told you the space between them are called as intercostal spaces which will be filled with intercostal muscles they are present in layers they are nothing but our body wall muscles and they have their own or respective vessels and nerves now if you look at this the last two spaces okay there are totally eleven pairs of spaces the last two spaces are actually open ventrally the last two space they don't reach anteriorly and just they are falling short off on the lateral midaxillary line they fall short there and naturally they are open ventral okay and you are able to see the lower ribs that is the 7th 8th 9th and 10th of which 8th 9th and 10th does not directly articulate with the sternum instead they articulate with the castle cartilage of the above and through that indirectly they articulate with the stern that is the mainly the 7th 8th 9th and tenth rib okay so mainly these seven ribs first two seven ribs are two ribs because they directly articulate to the sternum via their respective costal cartilages and the lower border of 7th to 10th forms the costal margin so this lower free margin of the caustic cartilage is actually called as the costal margin we have the right costal margin then you have the left costal margin now the upper part is actually called as the thoracic inlet and the lower part is actually called as the thoracic outlet the thoracic cavity as i told you it not only gives protection to the lungs and the heart so deep to the caster margin on either sides it also protects to some extent your liver on the right side your spleen on the left side these two organs and also to some extent it is stomach so it also gives some protection to the abdominal organs so this is actually called as a thoracic inlet or the beginning of the thoracic cavity or entry point would be the torrents now thoracic inlet is the term given by the anatomists which is bounded anteriorly by the upper border of the many brave sternum on either side by the first strip and posteriorly by the first thoracic vertebrae okay so posteriorly with the first thoracic vertebra upper border of the manibrium sternum and first strip at the sides so this is actually called as the thoracic inlet now clinicians refer the same inlet as the thoracic outlet instead of inlet they actually refer it as outlet because mainly the great vessels are actually coming out okay then the lungs the uppermost for the effects of the lung project beyond the first okay so is it all the structures are coming out now so many structures are also entering the major veins from the upper part of your body that is head neck and upper lip they enter into the torah so they are entering inside some of the nerves are actually entering inside some of the vessels are also which are going to supply the thoracic wall pericardium also they enter into the thorax so some structural center some structures leave the clinicians call these at the borasic outlet instead of the thoracic inlet and you look at the outlet it is not transversely oriented it is actually obliquely oriented so it is actually oriented downwards and forwards so it is angulated with the transverse plane approximately around 45 degrees why it is so because the ribs if you look at the anterior end of the rib it is at a lower level as compared to the posterior so the posterior end articulates with the corresponding vertebra but the anterior end does not lie to the arm at the level of its corresponding vertebrae the first rib articulates with the first thoracic vertebra but the anterior end lies at a lower level okay it is obliquely placed so the ribs are actually obliquely placed so that is why the inlet is also slanting and not only that the sternum is also starting at a lower level so anterior end of the rib dries at a lower level due to which the inlets loops downwards and forwards now coming to the thoracic outlet so as of now we call this as the thoracic outlet which is bounded by the 12th thoracic vertebra behind the zippy sternum anteriorly okay is actually the zifi sternum anteriorly and on either side by the 11th and 12th ribs they are not complete they don't reach the anterior most aspect on either side by the 12th rib and this large opening thoracic outlet in the recent state which means in the living condition is closed by the diaphragm okay it is closed by the diaphragm and on the sides it is formed by the costal margin as i told you by the seventh 8th 9th and 10th the costal cartilages so you have the right costal margin and then you have the left costal margin so what all is actually highlighted in the red color is your thoracic outlet okay so outlet is closed by the diaphragm and of course there are numerous openings in the diaphragm which admits major as well as some minor structures so with this short introduction ah about the basic features of the thorax and how the thoracic wall is actually constructed we will try to understand certain basic features of the osteology of the thorax to start with with the thoracic vertebrae so you all know that the thoracic vertebrae there are 12 thoracic vertebrae okay so there are actually 12 thoracic vertebra typical and atypical so typical means they possess the characteristic features of the thoracic vertebra majority link atypical thoracic vertebra which deviate from the normal characteristic so one or two they might be missing or they might show some variation now typical thoracic vertebra are second to eighth the second thoracic vertebra up to the yield to thoracic vertebra is typical thoracic vertebra whereas the 1st 9th 10th 11th and 12th the first one and the last 4 9 10 11 12 are atp for a sequential now first try to understand the parts of the vertebra this is actually called as the body of the vertebra you are able to see so this is a superior view and this is a lateral view so as i told you the anterior surface of the body is concave you are able to see this concavity which i mentioned in the first slide this is responsible for the concave primary curvature one of the factors the body you have centrum or the body of the vertebra then this is actually called as the neural arch which is actually formed by the pedicles the pedicles unite to form posterior the lamina and then the lamina units to form the spine then at the junction of the pedicle and the lamina what you see is the transverse process it is the transverse process then you also have the superior and inferior articular process superior and inferior articular processes okay the body has got an upper surface and lower surface between the body of the vertebra you have the intervertebral disc if you look at the body it is heart shaped the body is actually heart shaped and it is very body small not a very large body it is heart shaped as i told you then this foreign is actually called as the vertebral foramen which transmits the spinal cord the vertebral foramen is circular and again small as compared to the cervical vertebra cervical vertebra it is large and triangular and it has to accommodate the what do you call the bulging of the spinal cord okay so you have the enlargement the cervical and the lumbar enlargements because the plexus are there person which is going to innervate the limbs so here the vertebral foramen is actually small and rounded the spine is obliquely placed especially from second obliquity goes or increases up to the eighth thoracic vertebra then this is actually the superior and the inferior vertebral notch the superior is not very market but you see the inferior vertebral notch is actually very very marked okay the most striking features on the sides of the body you see this costal facets and they are present in the form of baby facets its half facets especially for the typical thoracic vertebra they are demi facets that means the upper facet will articulate the numerically corresponding rib the lower facet will articulate with the succeeding rib the lower facet will articulate with the succeeding rib that is why it is a daily facet means half faster in this the other half will be for the vertebral above and the vertebra below so they form a full face set and this is third the upper facet will be articulating with the third rib the lower demi facet for the fourth this is for the corresponding grip and this is for the what you call the succeeding same way the transverse process also has a oval facet which is for the tubercle of the rib okay so the tubercle of the rib will be articulating with the transverse process and they also form a joint which is actually called as the zygapophysial joint or osteotransverse joint if you look at the nature of the costal facet of the typical thoracic vertebra it will be convex in nature okay so because of the convexity what happens is the articulating facets are convex in nature between the tubercle and the transverse process of the vertebra it allows rotary moments okay it allows some rotary moments at this joint this is typical now as you go down especially the lower vertebrae a 9th 10th 11th especially the lower not the 11th and 12th 8th 9th and 10th what happens is the lower ribs especially over six ribs the costal facet is not convex it is only flat and because of this these joints allow only gliding movements not the rotary movements but the gliding movements so that is about the facets mainly for the demi facets on the head body and this is on the transverse process for the tubercle of them okay so heart shaped body two coastal debbie facets on the body as i told you upper facet for the corresponding and lower faucet for the succeeding rib so you are able to see these are half facets demi facets the vertebral foramen is round or circular and small not very large as the case of the cervical vertebra very short pedicles they also increase in size as they go downwards then as i told you superior notch you see it is not very much notched but inferior knowledge is very much conspicuous very deeply you can appreciate it more market so this is one of the future of typical thoracic vertebra so short and thick lamina and laminar going to form the spine transverse process projects at the junction of the pedicle and the lamina and also it bears an oval facet for articulation the tubercle of the superior articular faces are able to see they face posterior laterally superior articular facets they face posterior laterally inferior articular facets you see anterior medial so they are reciprocal in nature they reciprocate each other so the superior articular facet will articulate with the inferior articular facet of the vertebrae above so only then they can articulate if they face against each other that is why this is posterior lateral which is again a typical feature of the typical thoracic vertebra so spine i told you oblique and faces downwards that is about the typical thoracic vertebra heart shape the body route or circular vertebral foramen demi facets on the sides of the body over facet on the transverse process inferior vertebral notch is conspicuous than the superior so these major points you should remember now the air typical mainly the first one i told you is a typical in what way it will have only one coastal facet on the body full round no demi or half percent full round which means it is going to articulate with the first rim since there is no rip above it is articulating force with the first rib then the superior vertebral notch is marked in case of the atypical especially first thoracic vertebra which transmits the eighth the cervical nerve okay so superior notches will actually transmit the spinal nerves one segment above okay so t1 superior vertebral notch will transmit the eighth cervical spinal nerve well developed as i told you and the vertebral foramen is also large so it is somewhat resembling the cervical okay the cervical so that is why it is large and triangular not round or circular as in the case of typical thoracic vertebra so these points you should remember and see the spine is not oblique it is somewhat transverse or horizontally oriented okay so single facet full circular facet superior vertebral launch is marked okay then what you see is triangular vertebral foramen large which is large now coming to the next ninth thoracic vertebra it is almost same as that of the typical thoracic vertebra only one thing is only one db facet on the body there will not be any two daily facets and of course your transverse facet oval facet will be flat instead of being con bits okay so apart from that then if i said it is going to resemble the typical thoracic vertebra now tenth one the body is somewhat large slowly it is resembling you see the body is slowly increasing as to the form of lumbar vertebra large body lumbar type again only one facet you are able to see for the 10th 11th and 12th you are able to see only one single circular facet one single circular facet eleventh again one facet no facet on the transverse process okay so the tubercle is not going to articulate there is no facet on the transverse process no facet at all same way if you look at the towards the thoracic vertebra you see again only only one full facet and it is encroaching onto the medicine see here it is on the body slowly it has encroached onto the medicine towards the thoracic vertebra large body a single circular facet encroaching on to the vertebra no facet on the transverse process no facet on the transverse process for the 11th and the 12th rib okay so no facet and the transverse process bears three tubercles so superior tubercle inferior tubercle and one more lateral one which is going to again resemble the lumbar vertebra because they will have mamillary process and accessory transverse process same way here also it is slowly getting transition it is the transition stage into the lumbar vertebra and the inferior articular facet if you look at it see here it is outer instead of facing it medially it is twisted and outer inferior articular facet face forward and laterally so that is how you identify three points for 12 thoracic vertebra large body with one single facet round facet on the body no facet on the transverse process and the caster facet is encroaching onto the pedicle infill articular first is destroyed and it is facing forwards and laterally instead of forwards and immediately so we have seen about in brief about the thoracic vertebra so the first 9th 10th 11th and 12th are atypical second to eighth or typical thoracic vertebra now coming to the sternum so sternum is a example of flat bow it is made up of three parts nani brimster body of stern and then what you see is the zifi sternum okay manny brian sternum you're able to see the upper border is again you have a concave notch which is actually called as the jugular notch okay it is actually called as the jugular notch gives attachment to the interclavicular ligament then the lower border of the manibrium attaches to the body of the manimarian forming the manibrio sternal joint manipurnal joint is yes secondary cartilaginous joint it is actually a secondary cartilaginous joint the man embryo external joint and it actually ossifies at the age of 60. laterally you have the articular facet for the clavicular notch forming a saddle type of joint sternoclavicular joint so manipulating sternum is actually a communication between the axial skeleton and the appendicular skeleton since the clavicle articulate with its and then you also have the articulation for the first caster cartilage the first strip through the cascade cartridge is also articulating to the maniperio stern okay then below that you have as again a demi facet this facet is completed by the another demi facet by the side of the body of the sternum these two forms a combined facet for the second rib at the region of the manipurio sternal joint or this is actually called as the sternal angle the angle between the manibrium and then the body of the sternum is actually called as the sternal angle or angle of lewy which is actually called as the angle of louie anterior surface gives attachment to your pectoralis major muscle and then upper border sternocleidomastoid posterior part sternothyroid and sternohyoid muscles of the neck from the posterior upper part and then it will be related to the pleura posterior surface will be related to the pleura manibrium stern okay so this is actually called as the angle of louie where the second rib articulates so at the region of angle of fluid angle formed by the manipurium and the body of sternum the second rib articulates so this is through one way you can count the hips so at this manipulative angle you just go literally then you are actually palpating the second grip now apart from that there are many events taking place at the angle of louis one thing it corresponds the lower border of manipurium sternum or the angular fluid corresponds to the lower border of fourth thoracic vertebra t4 lower border t4 so it is at the junction of t4 and p5 okay so by divides or it is the demarcating line so between the superior and the inferior media stylum so counting of ribs in the region of triangle of louis second one i told you is it is the demarcating between the superior and the inferior mediastinum then the arch of iota arch of iota starts at this level makes an arch and then again ends at this level the anterior border of both the lungs are in close approximation at this manibrium sternum okay then the thoracic duct the largest lymphatic duct of our body crosses from the right side to the left side and the region of manibrim sternum your trachea bifurcates at the region of manibrium sternum your superior vena cava pierces the fibrous pericardium before opening it to the right atrium at the level of manibrium sternum or angel of louis at the external line sorry i've been telling you manipulating stunning merry minister minus the sternal angle or the angle of v so these are some of the events at the level of the angle of v beginning and ending of arch of phyota bifurcation of trachea thoracic that crossing from the right side to the left side okay so that is about the importance of the sternal angle next coming to the body of the sternum which is long thin and narrow you are able to see here it is actually a fusion of three to four pieces of sterner braid okay sternum bray or individual sternal what you call skeletal elements they fuse and not only that the either side sternum ray up they also fuse in the midline during your lateral folding of the embryo so fusion of force turner braid for the either side and again these four of this side and this side they fuse in the midline so lies opposite the fifth to eighth thoracic vertebra t5 t67 and e8 so upper border articulates forming the manibrio sternal joint lower border the zifi sternum laterally it is notched for the second third fourth fifth and sixth and seventh rib okay so mainly to second to seventh rib through the costal cartilages it receives the articulation lower end forms the zippy sternal joint okay so anteriorly again pectoralis major it gives attachment posteriorly it is actually related to the [Music] pleura deep to the plural of the lung but on the left side but on the left side between the fourth to sixth rib since the lung deviates laterally it is in direct contact with the fibrous pericardium of the heart okay the body of sternum opposite the fourth to sixth rib on the left half of these therm is actually direct contact with the fibrous pericardium okay so that is about the body of the stone ziphi sternum most variable structure it might be perforated it might have bifid split into two or deflected to one side it may just diffuse only to the left or to the right side and it ossifies at the age of 40 at the age of 40 years if is ossifies so it is actually present deep to the epi gastric fossa on the depth of the floor of the ap gastric fossa you can see these zippy sternum anteriorly the linear alpha is actually attached to it and on either sides it also gives attachment to your muscles external oblique muscles posterior surface gives attachment to [Music] the sternal fibers of the diaphragm then also your sternocostalis muscle one of the transversus porosis muscle all those things it gets attached okay so that is about the sternum then sternal puncture is also done uh to actually bone marrow biopsy for red bone marrow actually sternal puncture done and sometimes if some part is not used in the midline you can see a foramen which is actually called as the sternal foramen so it is asymptomatic and does not produce any functional deficiency or complications okay sometimes you can come across this external foramen and sternotomy midline splitting of the sternum to access the middle mediastinum in certain operating procedures is also done not only that the sternum is very sensitive to the nausea suction pain so with the help of knuckles you rub the sternum so you might be trying to actually awake or arouse a comatose patient okay so that is about the sternum so as i told you zifi sternum seventh cosmic cartilage articulates and utilizes the ap gastric fossa so we have seen about the thoracic vertebrae and the sternum now we are coming to the ribs so you have 12 pairs of ribs okay there are again examples of flat boards so wherever these boards any bones you take they are protective in nature they are flat bones you are bones of the wart of the skull its a flat board your ribs are flat boobs okay cfp your indium is an example of flat board so ribs if you look at the ribs they are flat boards elongated curved angulated twisted at their angles posteriorly to start with they pass backwards and laterally and then appropriately they turn forwards and the place where they are angulated the angular part of the rib or the angle of the rib is the most weakest point where breakage occurs or fracture occurs the angle increases from above downwards and the most oblique lip is the eighth rib the eighth rib you can see the obliquity is more pronounced okay you have two ribs and you have false ribs the first seven ribs articulate directly with the sternum through the costal cartilage so they are actually called as the true ribs whereas the remaining ribs eighth ninth and tenth are actually false ribs because they indirectly articulate through the costal cartilage of the above rib and 11th and 12th are actually called as the floating ribs they are actually called as the floating ribs so posteriorly the head of the rib articulates with the body the tubercle of the rib articulates the transverse process of the corresponding vertebra and anteriorly it articulates through the sternum they are actually our castle arches okay the castle elements they are actually the constant elements of the vertebra also arches of the vertebra even the cervical region is there even the lumbar region but during the course of development what happens is they regress okay they don't develop much even after all if it is present they regress if at all it is present so naturally it will produce certain conditions one example i will just tell at the end of this session in the applied anatomy so as i told you true ribs are seven pairs articulating the sternum directly and false ribs lower five pairs of ribs and eleventh and twelfth rib is actually called as the floating ribs so if you are able to see a structure of it typically please don't confuse true ribs and false ribs with typical and atp levels okay true and false are first to seventh is true and lower five pairs are actually false its typical ribs are third to ninth rib okay so they are they are the typical futures it is very difficult to differentiate from third to ninth grip the year typical ribs are first second tenth eleventh and the twelfth rib so they are a typical now what are the features of a typical rib here you are able to see the head of the rib then you have a constriction which is called as the neck of the rib then you see the tubercle of the rib then what you see here is the shaft of the rib and anteriorly the shaft will articulate with the costal cartilage the head of the rib bears two facets superior facet and inferior facet the superior facet will articulate with the vertebra above preceding vertebra and the inferior will articulate to the corresponding vertebra so they all articulate with the one above and the corresponding vertebra to the body of the vertebral sides of the vertebrae say demi facets then we have the neck so in the neck of the rib again you see a transverse groove for the posterior intercostal membrane then you have the tubercle of the ring again which bears a facet which is going to articulate with the transverse process of the corresponding vertebra so that also we have seen the vertebral transverse process base of acid upper vertebra the transverse process somewhat convex whereas in the lumo facet it is somewhat flat so that is why in the upper ribs these joints the rotary movements are possible whereas in the lower lips the movement is mostly of the gliding variety so you got the vertebral posterior head neck and the tubercle two facets as i told you so the tubercle the facet is flat and the posterior intercostal membrane will be attached then you see the shaft it is angulated you got a superior border inferior bond the inferior border is actually sharp as compared to the superior border which is blunt and rounded you got an external surface it has got an internal surface on the internal surface near to the inferior or lower border you see a group which is actually called as the coastal group so mainly your intercostal vessels posterior intercostal vessels and the intrapostal nerve will be lodged in this group okay so tubercle oval facet for articulation the transverse process shaft as i told you it is angulated and it is actually twisted so that is why when you put a rib on the any flat surface both the ends do not touch the surface because of its angulation so caster grew on the inner surface near the lower border so upper border is round and broad as i told you low bar is thin and sharp so these are the features of a typical rib a typical rip first strip very short stove ok and it is flat no angle at all there is only one facet on the head no two facets single circular facet on the head it has got an upper surface and lower surface because it is flat on the upper surface you see a groove okay and on the inner border of the group represents a tubercle which is called as the scalene tubercle this is actually called as a scalene tubercle and anterior part of the glue is for the subclavian vein and behind it is for the subclavian artery the scallion tubercle for the insertion of the skelenos anterior muscle okay two shallow grooves you are able to see on the upper surface as i told you absence of costal groove okay there is no costal groove short stout flat no angle single face shortest when you come across that is actually the first string second rib is twice the length of the first rib then on the middle of the shaft you see a tuberosity for the surrenders anterior muscle so through this uh feature you can identify the second variable again not well marked caustical group you have a very shallow caustic glue it is not deep or conspicuous so short costal group on the posterior part of the inner surface okay that is about the second rib coming to the tenth rib third to ninth are typical ribs if you look at the tenth rim it is same as a typical rib except instead of two facets on the head it will have a single articular facet okay same way you also know the tenth body has also got a single circular facet on the body instead of the demi flashlights eleventh rip absence of head and tubercle so you don't see a tubercle or you don't see an articular facet on the tubercle of the rib it is not absence of it absence of neck and only slightly angled again the groove is not that much the cosmic groove twelfth rib shorter than the lemon these two are actually floating ribs because they don't reach to the anterior aspect they just fall short of the lateral margin of our body wall so again no tubercle and no causal facet for the tubercle and it is shorter than the 11th rib so 10th 11th and 12th ribs are atp rips along with the first and second so fractures of the rib so what happens in case of the fractures of the rib if multiple ribs are actually fractured this fractured segment this fractured segment what happens is during inspiration it gets sucked in and during expiration it gets blown out okay it is pushed outwards during expiration and gets inwards pushed inwards during inspiration so actually it is happening the reverse of the normal this is actually called as the fly chest okay flying chest or fly segment this is actually called a spline just a flight checkman this will result in actually what happens is in multiple rift fractures this pliant segment will result in severe dyspnea it will result in actually severe dyspnea breathing problems because the lung might get compressed and not only that it will push almost the segment more towards the left side and the left lung will be compressed more in the flyer chest next is actually stove in the chest this happens when especially when you are driving a car your thoracic cage fits to the steering wheel then the sternum along on either side of the associated ribs what happens is they are compressed and they don't move during the respiration you're able to understand they don't move during the respiration and that is actually called as the stove in the chest so again this is actually a complication if not treated properly will lead to breathing difficulties okay which in chest so here you are able to see here called as the pescarian atom pigeon chest sternum projects forwards so projection of the sternum more forwards and the chest itself is having like a appearance of a pigeon it is rounded and most common in wreckage okay bony deficiency records it is also called as rakati rosary pigeon chest this is actually called as excavatum or pectus excavatum funnel chest sunken chest the lower segment of the chest is actually compressed inwards and this is actually called as the funnel chest okay so one is the pigeon just another one is the lower segment of the sternum is depressed and it is pushed backwards and it is actually called as the final chest again here you have dyspnea in the case of funnel chest cervical rib yes if the transverse process of the seventh cervical vertebra is long i told you know this ribs are costal elements are actually the transverse process extension this has to regress if it is present boney or sometimes if it is fibrous then it might compress certain nervous or blood vessels and based on the which structures are compressed it may produce neurological symptoms of vascular symptoms so if you remember exactly i would have discussed this cervical lips even in the applied anatomy of the brachial plexus okay same way here you are able to see lumbar ribs lower part again the costal elements if not regressed in the lumbar vertebrae you will be able to see these extensions a bit lengthy transverse process okay like cervical we also have lumbar threads in the costal element is not reduced or regressed during the process of the development so finally ah we will slightly touch upon the respiratory movements why because during the respiratory movements the dimensions or the diameters of the thorax are altered now during inspiration what happens is the anterior posterior diameter is increased transverse diameter is increased okay and even the vertical diameter is increased so the anterior posterior diameter the transverse diameter and the vertical diameter so that means all the three diameters of the thorax are actually increased now how actually this increase takes place so increase in the anterior posterior diameter is mainly by the bucket handle movement so you see the pump handle same way anterior posterior diameter is actually called as the bucket handle movement on the pump handle movement okay so mainly anterior posterior diameter sorry it should be the pump handle movement now the sternum what happens should move forwards and then during inspiration and then backwards so that is actually called as the pump handle movement the sternum moves forwards and then backwards now how actually this takes place by the elevation of the ribs it actually takes place by the elevation of the roots now active elevation is by the lower ribs and passive elevation is by the upper rims and lower ribs actually are elevated during normal quiet breathing and upper ribs come into action only during the forceful breathing now how the ribs elevate is you're able to see the axis of rotation passes through the vertebral postal join osteovertebral joint and this is also cos to transverse joint of one side will actually pass across the midline directly and it will go to the chondrosteronal joint of the opposite side so that is the axis of rotation which is possible to join between the tubercle and the transverse process head and the body of the vertebra of one side to the other side when the muscles contract the external oblique of one side and the internal oblique of the other side then actually the ribs are elevated passive elevation takes place in the upper rims but in the lower ribs what happens is near the angle it is twisted it is twisted so due to this twisting action which is actually called they are lifted like a handle of the bucket so that is why it is called the bucket handle movement so when the lower rims which are larger comes to the higher place the naturally the transverse diameter is increased by the bucket handle movement in pump handle movement as i told you what happens the sternum moves forwards during inspiration and backwards during expiration expiration is actually a passive action whereas an active action is the inspiration okay now what happens is upper ribs they move sternum upwards and forwards whereas the lower ribs what happens is move backwards these turn so that is why the sternal angle is formed due to the differential action of the upper and the lower ribs so the pump handle movement mainly increases the anterior posterior diameter when the sternum moves forwards and upwards and then backwards so transverse diameter by the bucket handle movement so increase in transverse diameters by the passive increase in upper ribs as i told you active increase is by the twisting of the lateral part of the rib lower ribs especially vertical diameter this diameter is increased by the piston action of the diaphragm so the diaphragm is a mobile septum which moves up and down it is 1.5 centimeters to 3 centimeter it moves to require breathing but in full inspiration it can displace up to 6 to 10 centimeters it is a principal muscle of respiration inspiratory muscle and what happens the higher its movement naturally it can act more actively so that it will be displaced more downwards okay and in children mostly the respiration is abdominal because the diaphragm is the principal muscle still the angle of ribs are not yet formed so mainly it is abdominal in respiration okay and the inspiration is actually one second and the expiration is three seconds the timing of inspiration and inspiration the other muscles apart from the intercostal muscles which we are going to see in the next session in detail in the intercostal spaces the quadratus lumbora muscle fixes the last two ribs then you have the sternocleidomastoid muscle which elevates the first rib along with the manibrim sternum especially during deep breathing and your pectoral muscles all aid in the respiration they are accessory respiratory muscles okay so by the piston movements the vertical diameter is actually increased by the piston movements of the diaphragm so your thoracic age diameters or your thoracic cavity diameters are increased anterior posterior diameter by the pump handle movement transverse diameter by the bucket handle movement most active in the lower ribs and the vertical diameter by the piston action of the diaphragm so thank you very much for your patient listening we will meet again in one more lecture