بسم الله الرحمن الرحيم

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2 بسم الله الرحمن الرحيم * Last lecture we talked about : thoracic wall sternum ribs (according to their features they are divided into typical and atypical) vertebral column ( which is made of 33 vertebrae ) : each vertebra is adapted according to its own function. each vertebra is made of body, arch and 7 processes. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> *How vertebrae are connected to each other?? they are connected by : 1) joints 2) ligaments * joints of vertebrae : ( 2 kinds ) 1) inter vertebral disk : - between bodies of the vertebrae - each two adjoined vertebrae are connected by cartilaginous disk (kind of joint = cartilaginous joint) Remember: joints are named according to the fibrous tissue between the two connected bones. Cartilaginous joint From birth to death it is cartilage Secondary cartilaginous Primery cartilaginous At birth it is cartilage but at 15 or 16 years old it converted into bone.

3 NOTE: Inter vertebral disks are secondary cartilaginous ( so we can bend and move easily ). 2) facets joints : - the superior articular processes are connected to the inferior articular processes of the upper vertebra. - kind of joint = synovial plane ( plane = the movement is only sliding to conform the vertebrae while extension and flexion ). *ligaments of vertebrae: 1) Anterior longitudinal ligament: (connects the bodies of the vertebrae anteriorly) - long ligament -anterior to the vertebrae - starts from cervical region and ends at sacrum. 2) Posterior longitudinal ligament: ( to see it cut the arch of the vertebrae). - connects the bodies of the vertebrae posteriorly. Posterior View: Never be afraid to laugh at yourself, after all, you could be missing out on the joke of the century ;) Dame Edna Everage

4 3) Spines ligaments: ( 2 kinds) A) Inter spinous ligaments : between spines of two adjoined vertebrae. B) supra spinous ligaments : on the tips of spines *Thoracic vertebrae features:( 12 vertebrae) - Typical thoracic vertebrae (2-9) - Atypical thoracic vertebrae (1, 10-12) Remember: Typical rips from 3 to 9 (Made of : body (directed anteriorly), arch (directed posteriorly), vertebral canal and seven processes(2 superior, 2 inferior, 2 transverse and one spine ) Then why they are different?? 1)Typical thoracic vertebrae : - heart (cylindrical) shape body. - each vertebra body contains 2 facets : A) the first is near the upper border of the body(to articulate with rib s head) B)the second is near the lower border of the body Note : ½ facet from the upper vertebra + ½ facet from the lower vertebra = complete circular facet to articulate with head of the rip

5 -The transverse process also contains facet ( to articulate with tubercle of the rip) - The spine is long,tapering and directed downward. 2)Atypical thoracic vertebrae : - Vertebra number 1: A)containing same above facets B)the spine is horizontal (it will lay horizontally on a table ). - Vertebrae : (sry couldn t find picture for them ) A) their bodies contain only one facet WHY?? Because the eleventh and twelfth rips their heads are not divide to articulate with two vertebrae ( articulate only with one complete circular facet on vertebra 11 and 12 ) (11 with 11 and 12 with 12 ) B)the transverse process has no facet ( there is no tubercle on the eleventh and 12 th ribs) Note : -The thoracic vertebrae are modified to adapt to their own function (to articulate with ribs). Example : Rib number 7 its head will ar culate with (the same number +number - 1(the vertebral above) body of vertebra 7 and 6,BUT the tubercle of rib number 7 will only articulate with the transverse process of vertebra number7. (the doctor gave same example about rip number 4) Note : Ribs are connected to thoracic vertebrae by two joints: 1) costovertebral joint (between ribs and vertebrae) (anything related to rib is called costal ) 2) costotransverse (between ribs and transverse processes)

6 Note: Only thoracic vertebrae are modified to articulate with rips so the head of rip number one will only articulate with vertebra number one. *Thoracic region layers: Skin Superficial fascia (containing breast ) Deep fascia (named also pectoral fascia because it covers pectoral major muscle) Deep region (which we ll discuss its muscles, innervations and blood vessels (arterial and venas )) Note: The muscles we will talk about are related to the respiratory system muscles.(muscles of the respiration) * Muscles of the respiration: ( 3 groups) 1)muscles from vertebral column to the rips (from the back) 2) muscles will connect rips together in the intercostals spaces ( intercostals muscles ) 3) the diaphragm : a par on between two cavi es (abdominal cavity and thoracic cavity ) النجاح سلم ال تستطيع تسلقه ويداك في جيبك (;..

7 *Intercostals muscles : - All of them are originated from the lower border of the rib above. - Are inserted into the upper border of the rip below. - innervated by intercostals nerves Cross section

8 (We differen ate between the 3 layers by the direction of movement) Directions: 1) External intercostals: outer layer - Downward, forwards and medially 2) Internal intercostals: in the middle - Downward, backward and laterally 3) Innermost intercostals: inner layer (laying on lungs ) - Downward, backward and laterally *Nerve supply: The thoracic segments of the spinal cord will give nerves (thoracic nerves ), (T1 of the brachial plexus is one of them ): - Nerves are between ribs so they are called (intercostals nerves ). - We have 12 nerves so we ll have 11 intercostals spaces. - Nerve number 12 is called sub costal. - Divided into typical (T3-T6) and atypical. A) T1 is atypical (went to brachial plexus). B) T2 is atypical because it gives cutaneous branch to arm medial aspect. C) T7-t12 are atypical they supply the anterior abdominal wall. - Typical thoracic nerves are originated from the intervertebral foramen and will move in between the intercostals spaces (between the internal intercostals muscle and the innermost intercostals muscle as they were one muscle but when the nerves were developed and walked between them they were divided into two muscles.( for that they have the same direction), these nerves will end anteriorly at sternum.

9 - Each nerve has motor and sensory function. - The motor function of the thoracic nerves is to supply intercostals muscles. - The sensation function of the typical nerves at lateral side is supplying the lateral aspect of the thoracic wall by the lateral cutaneous nerve, then at sternum sides they ll give the anterior cutaneous nerve for the anterior skin aspect of the thoracic wall. *Action:(insertion to origin) (we ll pull the lower rips upward) - going downward from first rip to the twelfth rip: A) The diameter of rips will increase. B) The rips get longer. So the action is widening the thoracic cavity by pulling the largest rip( by diameter ) upward, and that s what we need so lungs could enlarge easily when we breath (inspiration), then we will narrow the thoracic cavity (expiration). *Quiet Inspiration : We need to widen the thoracic cavity by widening the thoracic cavity by 3 diameters : 1) Vertical diameter ( up to down ), (superior-inferior) - First to enlarge - by the diaphragm, if there is contraction it ll be contracted downward (So the vertical diameter is widened). 2) Transverse diameter -Second to enlarge - By the intercostals muscles which will pull the ribs upward increasing the transverse diameter. (first action) 3) Anterior posterior diameter -Third to enlarge

10 - When the longest rib is pulled upward (connected to the vertebral column posteriorly and to the sternum anteriorly, so it will push the sternum anteriorly (to avoid fracture) increasing the anterior posterior diameter.(second action) Note: The intercostals muscles are only responsible for increasing in transverse and anterior posterior diameters *Quiet expiration: When we relax the intercostals muscles and the diaphragm everything will return to its original place. (the doctor said sth about the lung but I didn t understand it ) *Blood vessels : Arterial supply : (in all spaces ) - Anteriorly: 2 anterior intercostals arteries from the internal thoracic (on both sides of sternum) it ends at the sixth intercostals space then it will divide into two branches: A) Superior Epigastric branch to stomach b)musculophrenic branch to diaphragm - Posteriorly: single intercostals artery (branches from aorta: it will give right and left branches for T3-T12 while T1 and T2 will take branches from the costocervical artery (will give rips and cervical) a branch of the subclavian artery )

11 Being a medical student doesn t mean that your life is all about studying,don t convince yourself that you have no time, now at this age it s your chance to be creative, work hard and help people. Remember always that you are extraordinary person,so you must do extraordinary things ;) I tried my best, sry for any mistakes Done by: Aseel Al-Zaghoul