THORACIC CAGE
It is osseocartilaginous, elastic cavity. It shows above inlet, below outlet. Antero-posterior diameter is less than transverse diameter.
Boundaries :
Anterior : Sternum, costal cartilages and anterior part of ribs.
Posterior : Twelve thoracic vertebra, inter vertebral discs, twelve ribs (posterior part).
On each side : Twelve ribs with their cartilages.
Shape :
Shape of it is cone like from above downward. Narrow above which becomes broad below. Transversely it is kidney (bean) shaped in adult but in infants circular.
Functions :
1) Protection of lungs, heart and all other organs in thorax.
2) Play a major role in inspiration and expiration by its elastic nature.
INLET
Upper narrow part of thorax bean shaped. Its transverse diameter is 10 cm and antero-posterior diameter is 5-6 cm. Plane of inlet goes downward and anteriorly. Anterior end 3-4 cm lower than vertebral end.
Boundaries
Anterior : Upper margin of manubrium sterni
Posterior : Upper surface of body of first thoracic vertebra.
On each side : First rib and its cartilage.
Supra pleural membrane or Sibson’s fascia close inlet from above on right and left side. It separates neck and thoracic cavity. Suprapleural membrane is triangular in shape (right and left half) having base and apex. Apex shows attachment on tip of transverse process of seventh cervical vertebra and base shows attachment on inner margin of first rib and cartilage.
Structures passing through inlet :
Muscles : Sternohyoid, sternothyroid and longus colli
Vessels : Brachiocephalic artery ( right side), left common carotid artery and left subclavian artery, right and left brachiocephalic veins, first posterior intercostal veins, superior intercostal veins, internal thoracic veins, inferior thyroid veins.
Nerves : Phrenic nerves, vagus nerves, sympathetic trunks, first thoracic nerves
Viscera : Trachea, esophagus, thymus, apex of lung
OUTLET
It is lower broad part of thoracic cage. Diaphragm separate thorax from abdominal cavity.
Boundaries :
Anterior : 7th to 10th costal cartilages forming costal margin with xiphoid process.
Posterior : body of 12th thoracic vertebra.
On both sides : Costal margin and 7th to 12th ribs.
Sternal angle (angle of louis) :
It is a point where manubrium and body of sternum form joint (manubrio-sternal). Level of it is inter-vertebral disc between fourth and fifth thoracic vertebra posteriorly and second costal cartilage anteriorly.
Importance :
1) For rib counting from second costal cartilage.
2) Trachea bifurcates at this level.
3) Arch of aorta starts and ends at this level.
4) Plane separating superior and inferior mediastinum pass at this level.
5) Azygos vein terminate into superior vena cava at this level.
6) Thoracic duct goes from right to left side.
INTERCOSTAL SPACES
Intercostal spaces are space between two ribs and cartilages. There are eleven intercostal spaces present on each side.
Contents of intercostal spaces are muscles,vessels,nerves and lymphatics.
Muscles : External intercostal, internal intercostal and intercostalis intimus.
It is osseocartilaginous, elastic cavity. It shows above inlet, below outlet. Antero-posterior diameter is less than transverse diameter.
Boundaries :
Anterior : Sternum, costal cartilages and anterior part of ribs.
Posterior : Twelve thoracic vertebra, inter vertebral discs, twelve ribs (posterior part).
On each side : Twelve ribs with their cartilages.
Shape :
Shape of it is cone like from above downward. Narrow above which becomes broad below. Transversely it is kidney (bean) shaped in adult but in infants circular.
Functions :
1) Protection of lungs, heart and all other organs in thorax.
2) Play a major role in inspiration and expiration by its elastic nature.
INLET
Upper narrow part of thorax bean shaped. Its transverse diameter is 10 cm and antero-posterior diameter is 5-6 cm. Plane of inlet goes downward and anteriorly. Anterior end 3-4 cm lower than vertebral end.
Boundaries
Anterior : Upper margin of manubrium sterni
Posterior : Upper surface of body of first thoracic vertebra.
On each side : First rib and its cartilage.
Supra pleural membrane or Sibson’s fascia close inlet from above on right and left side. It separates neck and thoracic cavity. Suprapleural membrane is triangular in shape (right and left half) having base and apex. Apex shows attachment on tip of transverse process of seventh cervical vertebra and base shows attachment on inner margin of first rib and cartilage.
Structures passing through inlet :
Muscles : Sternohyoid, sternothyroid and longus colli
Vessels : Brachiocephalic artery ( right side), left common carotid artery and left subclavian artery, right and left brachiocephalic veins, first posterior intercostal veins, superior intercostal veins, internal thoracic veins, inferior thyroid veins.
Nerves : Phrenic nerves, vagus nerves, sympathetic trunks, first thoracic nerves
Viscera : Trachea, esophagus, thymus, apex of lung
OUTLET
It is lower broad part of thoracic cage. Diaphragm separate thorax from abdominal cavity.
Boundaries :
Anterior : 7th to 10th costal cartilages forming costal margin with xiphoid process.
Posterior : body of 12th thoracic vertebra.
On both sides : Costal margin and 7th to 12th ribs.
Sternal angle (angle of louis) :
It is a point where manubrium and body of sternum form joint (manubrio-sternal). Level of it is inter-vertebral disc between fourth and fifth thoracic vertebra posteriorly and second costal cartilage anteriorly.
Importance :
1) For rib counting from second costal cartilage.
2) Trachea bifurcates at this level.
3) Arch of aorta starts and ends at this level.
4) Plane separating superior and inferior mediastinum pass at this level.
5) Azygos vein terminate into superior vena cava at this level.
6) Thoracic duct goes from right to left side.
INTERCOSTAL SPACES
Intercostal spaces are space between two ribs and cartilages. There are eleven intercostal spaces present on each side.
Contents of intercostal spaces are muscles,vessels,nerves and lymphatics.
Muscles : External intercostal, internal intercostal and intercostalis intimus.
External intercostal
It extends from tubercle of rib to costochondral junction anteriorly between costochondral junction to sternum replaced by external intercostal membrane. Posteriorly continuous with posterior layer of superior costotransverse ligament.
Origin : It shows origin from lower border of upper rib.
Insertion : It shows insertion on outer lip of upper border of lower rib. Anterior part of it shows direction of fibres downwards, forwards and medially while in posterior part direction of fibres is downwards and laterally.
Nerve supply : Intercostal nerve of same intercostal space.
Action : It elevates ribs for inspiration.
Internal intercostal :
It extends from lateral border of sternum to angle of rib posteriorly replaced by internal intercostal membrane. Posteriorly continuous with anterior layer of superior costotransverse ligament.
Origin : It shows origin from costal groove of upper rib.
Insertion : It shows insertion on area between two lips of lower rib. Anterior part of it shows direction of fibres downwards, backwards and laterally which is right angle to direction of fibres of external intercostal.
Nerve supply : Intercostal nerve of same intercostal space.
Action : It depress ribs for expiration.
Intercostalis intimus :
It is part of inner most muscles of thorax formed by transversus thoracis. Transversus thoracis formed by subcostalis, intercostalis intimi and Sternocostalis.
Subcostalis :
It is present in intercostal spaces of lower part of thorax near angle.
Origin : It shows origin from inner surface of upper rib near angle.
Insertion : It shows insertion on inner surface of second or third rib below. Direction of fibres is same like internal intercostal.
Action : It depress ribs.
Intercostalis intimi :
It is present in middle 2/4th part of intercostal spaces.
Origin : It shows origin from inner surface of upper rib.
Insertion : It shows insertion on inner surface of rib below. Direction of fibres is same like internal intercostal.
Action : It depress ribs.
Sternocostalis :
It is present in anterior part of intercostal spaces.
Origin : It shows origin from lower 1/3rd part of posterior surface of sternum, xiphoid process and costal cartilages of lower three or four true ribs.
Insertion : It shows insertion on inner surface of lower ribs and costal cartilages of second to sixth ribs. Direction of fibres is same like internal intercostal.
Action : It depress ribs.
It extends from tubercle of rib to costochondral junction anteriorly between costochondral junction to sternum replaced by external intercostal membrane. Posteriorly continuous with posterior layer of superior costotransverse ligament.
Origin : It shows origin from lower border of upper rib.
Insertion : It shows insertion on outer lip of upper border of lower rib. Anterior part of it shows direction of fibres downwards, forwards and medially while in posterior part direction of fibres is downwards and laterally.
Nerve supply : Intercostal nerve of same intercostal space.
Action : It elevates ribs for inspiration.
Internal intercostal :
It extends from lateral border of sternum to angle of rib posteriorly replaced by internal intercostal membrane. Posteriorly continuous with anterior layer of superior costotransverse ligament.
Origin : It shows origin from costal groove of upper rib.
Insertion : It shows insertion on area between two lips of lower rib. Anterior part of it shows direction of fibres downwards, backwards and laterally which is right angle to direction of fibres of external intercostal.
Nerve supply : Intercostal nerve of same intercostal space.
Action : It depress ribs for expiration.
Intercostalis intimus :
It is part of inner most muscles of thorax formed by transversus thoracis. Transversus thoracis formed by subcostalis, intercostalis intimi and Sternocostalis.
Subcostalis :
It is present in intercostal spaces of lower part of thorax near angle.
Origin : It shows origin from inner surface of upper rib near angle.
Insertion : It shows insertion on inner surface of second or third rib below. Direction of fibres is same like internal intercostal.
Action : It depress ribs.
Intercostalis intimi :
It is present in middle 2/4th part of intercostal spaces.
Origin : It shows origin from inner surface of upper rib.
Insertion : It shows insertion on inner surface of rib below. Direction of fibres is same like internal intercostal.
Action : It depress ribs.
Sternocostalis :
It is present in anterior part of intercostal spaces.
Origin : It shows origin from lower 1/3rd part of posterior surface of sternum, xiphoid process and costal cartilages of lower three or four true ribs.
Insertion : It shows insertion on inner surface of lower ribs and costal cartilages of second to sixth ribs. Direction of fibres is same like internal intercostal.
Action : It depress ribs.
Intercostal vessels and nerves
Arteries
Intercostal arteries :
Intercostal space contains two anterior and one posterior intercostal arteries.
Posterior intercostal arteries :
In upper two spaces these are branches of superior intercostal arteries (branches from costocervical trunk of subclavian artery) and in lower spaces branches of descending thoracic aorta. Right sided posterior intercostal arteries longer than left sided because aorta present on left side.
Right posterior intercostal artery after its origin from aorta goes backwards and laterally. It crosses vertebral column and posterior to oesophagus, thoracic duct, azygos vein and sympathetic trunk. Left posterior intercostal artery after its origin from aorta goes backwards and laterally in relation with vertebra and posterior to hemiazygos vein and sympathetic trunk.
Then both arteries goes to angle of upper ribs to costal groove. In costal groove it lies between internal intercostal and intimus muscle. Anteriorly artery anastomoses with upper anterior intercostal artery. In costal groove relations are intercostal vein, artery and nerve from above downward.
Branches :
1) Collateral artery :
It gives out a collateral branch near angle of rib which runs in relation with upper margin of rib of respective intercostal space. Collateral branch anastomoses with lower anterior intercostal artery.
2) Dorsal artery :
A dorsal branch goes dorsally and supplies muscles and skin of back of neck. A spinal branch of it enters vertebral canal and supplies vertebra, spinal cord and meninges.
3) Muscular artery :
To intercostal muscles, pectoral muscles and serratus anterior muscle.
4) Lateral cutaneous artery :
Runs along with lateral cutaneous nerve. It supplies skin of lateral trunk.
5) Mammary branches :
Mammary branches supply pectoral muscles, skin and tissues of breast after giving branches to second to fourth intercostal spaces.
Anterior intercostal arteries :
These are present in all intercostal spaces except last two. Two anterior intercostal arteries are present in each space upper and lower. They anastomoses with collateral branch and proper posterior intercostal artery. In upper six intercostal spaces these are the branches of internal thoracic artery. In seventh to ninth spaces are branches of musculo-phrenic artery.
Arteries
Intercostal arteries :
Intercostal space contains two anterior and one posterior intercostal arteries.
Posterior intercostal arteries :
In upper two spaces these are branches of superior intercostal arteries (branches from costocervical trunk of subclavian artery) and in lower spaces branches of descending thoracic aorta. Right sided posterior intercostal arteries longer than left sided because aorta present on left side.
Right posterior intercostal artery after its origin from aorta goes backwards and laterally. It crosses vertebral column and posterior to oesophagus, thoracic duct, azygos vein and sympathetic trunk. Left posterior intercostal artery after its origin from aorta goes backwards and laterally in relation with vertebra and posterior to hemiazygos vein and sympathetic trunk.
Then both arteries goes to angle of upper ribs to costal groove. In costal groove it lies between internal intercostal and intimus muscle. Anteriorly artery anastomoses with upper anterior intercostal artery. In costal groove relations are intercostal vein, artery and nerve from above downward.
Branches :
1) Collateral artery :
It gives out a collateral branch near angle of rib which runs in relation with upper margin of rib of respective intercostal space. Collateral branch anastomoses with lower anterior intercostal artery.
2) Dorsal artery :
A dorsal branch goes dorsally and supplies muscles and skin of back of neck. A spinal branch of it enters vertebral canal and supplies vertebra, spinal cord and meninges.
3) Muscular artery :
To intercostal muscles, pectoral muscles and serratus anterior muscle.
4) Lateral cutaneous artery :
Runs along with lateral cutaneous nerve. It supplies skin of lateral trunk.
5) Mammary branches :
Mammary branches supply pectoral muscles, skin and tissues of breast after giving branches to second to fourth intercostal spaces.
Anterior intercostal arteries :
These are present in all intercostal spaces except last two. Two anterior intercostal arteries are present in each space upper and lower. They anastomoses with collateral branch and proper posterior intercostal artery. In upper six intercostal spaces these are the branches of internal thoracic artery. In seventh to ninth spaces are branches of musculo-phrenic artery.
Internal thoracic artery
It is branch of first part of subclavian artery. It arises 2 cm above sternal end of clavicle. It enters thoracic cavity after passing behind sternal end of clavicle. Here it is crossed by phrenic nerve from lateral to medial side. It goes vertically downwards posterior to upper six costal cartilages. At sixth costal cartilage it divides into musculo-phrenic and superior epigastric artery. Branches :
1) Pericardiophrenic artery : It runs along with phrenic nerve. It supplies pericardium, diaphragm, pleura.
2) Mediastinal : Small branches supply thymus, mediastinal fat.
3) Anterior intercostal
4) Perforating : It is present in upper six intercostal spaces. It supplies muscles and skin of pectoral region.
5) Superior epigastric : It goes downwards posterior to seventh costal cartilage. It enters rectus sheath between xiphoid process and costal origin of diaphragm. It anastomoses with inferior epigastric artery.
6) Musculo-phrenic : It goes downwards posterior to seventh to ninth costal cartilage. It gives out two anterior intercostal arteries in seventh to ninth intercostal spaces.
7) Pericardial : It supplies pericardium.
8) Sternal : It supplies periosteum of posterior surface of sternum and red marrow of sternum.
Intercostal nerves
There are eleven pairs of intercostal nerves from ventral ramus of thoracic nerves. Twelfth thoracic nerve forms subcostal nerve. Upper three nerves also supply upper limb and lower five nerves (T7-T11) supply abdominal wall. Third to sixth nerves are typical thoracic nerves and they supply thoracic wall. Subcostal nerve supply abdominal wall and gluteal skin.
Course of intercostal nerves :
Typical intercostal nerve after its exit from inter vertebral foramen reaches below neck of rib. Lies medial to superior costo-transverse ligament. Goes upward and laterally posterior to sympathetic trunk. Then it enters in costal groove. In costal groove vein, artery and nerves lies from above downward. In posterior part of groove it lies between pleura and internal intercostal membrane. And remaining part nerve lies between intercostalis intimi and internal intercostal muscle. In anterior part nerve crosses internal thoracic vessels and sternocostalis muscle. It pierces internal intercostal muscle and external intercostal membrane, pectoralis major to terminate as anterior cutaneous nerve.
Branches :
1. Muscular branches : It gives out branches to intercostal muscles, transversus thoracis, serratus posterior superior muscles.
2. Collateral branches: It arises near angle of rib. It goes anteriorly in same intercostal space in its lower part. It supplies muscles present in same space.
3. Lateral cutaneous branches : It arises near angle of rib. It pierces internal and external intercostal muscles in mid axillary line. After dividing into anterior and posterior branches supply skin of thorax.
4. Anterior cutaneous branches : It arises near margin of sternum after piercing supplies skin of thorax by two branches medial and lateral.
5. Communicating branches : It gives branches to sympathetic ganglion by grey and white rami communicates.
There are eleven pairs of intercostal nerves from ventral ramus of thoracic nerves. Twelfth thoracic nerve forms subcostal nerve. Upper three nerves also supply upper limb and lower five nerves (T7-T11) supply abdominal wall. Third to sixth nerves are typical thoracic nerves and they supply thoracic wall. Subcostal nerve supply abdominal wall and gluteal skin.
Course of intercostal nerves :
Typical intercostal nerve after its exit from inter vertebral foramen reaches below neck of rib. Lies medial to superior costo-transverse ligament. Goes upward and laterally posterior to sympathetic trunk. Then it enters in costal groove. In costal groove vein, artery and nerves lies from above downward. In posterior part of groove it lies between pleura and internal intercostal membrane. And remaining part nerve lies between intercostalis intimi and internal intercostal muscle. In anterior part nerve crosses internal thoracic vessels and sternocostalis muscle. It pierces internal intercostal muscle and external intercostal membrane, pectoralis major to terminate as anterior cutaneous nerve.
Branches :
1. Muscular branches : It gives out branches to intercostal muscles, transversus thoracis, serratus posterior superior muscles.
2. Collateral branches: It arises near angle of rib. It goes anteriorly in same intercostal space in its lower part. It supplies muscles present in same space.
3. Lateral cutaneous branches : It arises near angle of rib. It pierces internal and external intercostal muscles in mid axillary line. After dividing into anterior and posterior branches supply skin of thorax.
4. Anterior cutaneous branches : It arises near margin of sternum after piercing supplies skin of thorax by two branches medial and lateral.
5. Communicating branches : It gives branches to sympathetic ganglion by grey and white rami communicates.
Intercostal veins
Two anterior intercostal veins are present in each intercostal space in nine intercostal spaces. It drains into internal thoracic vein in upper six intercostal spaces and in lower spaces drain into musculo-phrenic vein.
There are eleven posterior intercostal veins present. On right side 1st drains into brachiocephalic vein, 2nd, 3rd join forming 4th superior intercostal vein, 5 to 11 and subcostal vein drain into azygos vein. On left side 1st drains into brachiocephalic vein, 2nd, 3rd, 4th join forming superior intercostal vein which drains into left brachiocephalic vein, 5 to 8th drains into accessory hemiazygos vein and 9 to 11 with subcostal vein drain into hemiazygos vein.
Two anterior intercostal veins are present in each intercostal space in nine intercostal spaces. It drains into internal thoracic vein in upper six intercostal spaces and in lower spaces drain into musculo-phrenic vein.
There are eleven posterior intercostal veins present. On right side 1st drains into brachiocephalic vein, 2nd, 3rd join forming 4th superior intercostal vein, 5 to 11 and subcostal vein drain into azygos vein. On left side 1st drains into brachiocephalic vein, 2nd, 3rd, 4th join forming superior intercostal vein which drains into left brachiocephalic vein, 5 to 8th drains into accessory hemiazygos vein and 9 to 11 with subcostal vein drain into hemiazygos vein.
Respiratory movements
Respiration includes inspiration and expiration. These movements takes place at costo-vertebral and manubrio-sternal joints. During inspiration there is increase in volume of thoracic cavity.
Antero-posterior diameter :
Anterior end of ribs along with sternum moves forward and upward. Axis of this passes through centre of costo-vertebral and costo-transverse joints. It occurs in vertebrosternal ribs. External intercostal muscle of same side along with internal intercostal muscle of opposite side help in this movement. Second to sixth rib along with sternum moves up and down. This increases antero-posterior diameter of thorax. This movement therefore called pump handle movement
Respiration includes inspiration and expiration. These movements takes place at costo-vertebral and manubrio-sternal joints. During inspiration there is increase in volume of thoracic cavity.
Antero-posterior diameter :
Anterior end of ribs along with sternum moves forward and upward. Axis of this passes through centre of costo-vertebral and costo-transverse joints. It occurs in vertebrosternal ribs. External intercostal muscle of same side along with internal intercostal muscle of opposite side help in this movement. Second to sixth rib along with sternum moves up and down. This increases antero-posterior diameter of thorax. This movement therefore called pump handle movement
Transverse diameter :
Shafts of ribs lies at lower level than its ends. It moves upward and outward. It occurs in vertebrochondral ribs. Axis for this movement passes through costo-vertebral and costo-sternal joints. Lower intercostal muscle and diaphragm help in this movement. Seventh to tenth rib moves up and down. This increases transverse diameter of thorax. This movement therefore called bucket handle movement
Shafts of ribs lies at lower level than its ends. It moves upward and outward. It occurs in vertebrochondral ribs. Axis for this movement passes through costo-vertebral and costo-sternal joints. Lower intercostal muscle and diaphragm help in this movement. Seventh to tenth rib moves up and down. This increases transverse diameter of thorax. This movement therefore called bucket handle movement
Vertical diameter :
It is increased by descent of diaphragm. During inspiration diaphragm contracts and goes down increasing vertical diameter.
Muscles for inspiration :
Diaphragm is principle muscle for inspiration assisted by intercostal muscle. Other muscles which comes into play during forced inspiration are sternocleidomastoid, scalene group, pectoralis major and minor, serratus anterior, quadratus lumborum and erector spinae.
Muscles for expiration :
Expiration is because of elastic recoil of lung but during forced expiration muscles are involved. Muscles of anterior abdominal wall and latissimus dorsi are for forced expiration.
It is increased by descent of diaphragm. During inspiration diaphragm contracts and goes down increasing vertical diameter.
Muscles for inspiration :
Diaphragm is principle muscle for inspiration assisted by intercostal muscle. Other muscles which comes into play during forced inspiration are sternocleidomastoid, scalene group, pectoralis major and minor, serratus anterior, quadratus lumborum and erector spinae.
Muscles for expiration :
Expiration is because of elastic recoil of lung but during forced expiration muscles are involved. Muscles of anterior abdominal wall and latissimus dorsi are for forced expiration.
Joints of Thorax
Following joints are present in thoracic cage
1) Manubriosternal joint
It is formed by lower end of manubrium and upper end of body of sternum. It is secondary cartilaginous type of joint. Only slight movement of body of sternum is possible at the time of respiration.
2) Costovertebral joint
It is formed by head of rib and body of corresponding vertebra but in typical rib also with higher vertebra. It is plane synovial type of joint. Intra-articular ligament present between crest and two articular facets on facets of head of rib to intervertebral disc. Capsular ligament shows attachment on articular margin. Triradiate ligament upper and lower band shows attachment on anterior part of head of rib to sides of upper and lower vertebra. Middle band shows attachment on intervertebral disc.
3) Costotransverse joint
It is formed by tubercle of a typical rib and transverse process of corresponding vertebra. It is a plane synovial type of joint. Capsular ligament shows attachment on articular margin. Superior costotransverse ligament shows two layers anterior and posterior shows attachment on crest on neck of rib to transverse process of vertebra above. Inferior costotransverse ligament shows attachment on posterior surface neck of rib to transverse process of vertebra. Lateral costotransverse ligament shows attachment on lateral non articular part of tubercle to tip of transverse process of vertebra.
4) Costochondral joint
It is formed by each rib with its cartilage anteriorly. It is a primary cartilaginous type of joint. There is no any movement.
5) Chondrosternal joint
It is formed by medial end of first to seventh costal cartilage and sternum. First chondrosternal joint is primary cartilaginous type of joint. Others are synovial type of joint.
6) Interchondral joint
It is formed in between fifth to ninth costal cartilages. Ninth and tenth costal cartilage is joined with each other by fibrous tissue.
7) Intervertebral joint
It is formed in between body of upper and lower vertebra. It is secondary cartilaginous type of joint. Fibrocartilaginous intervertebral disc is present in between them. This disc shows annulus fibrosus peripherally and nucleus pulposus centrally. Anterior and posterior longitudinal ligaments are present between them.
Following joints are present in thoracic cage
1) Manubriosternal joint
It is formed by lower end of manubrium and upper end of body of sternum. It is secondary cartilaginous type of joint. Only slight movement of body of sternum is possible at the time of respiration.
2) Costovertebral joint
It is formed by head of rib and body of corresponding vertebra but in typical rib also with higher vertebra. It is plane synovial type of joint. Intra-articular ligament present between crest and two articular facets on facets of head of rib to intervertebral disc. Capsular ligament shows attachment on articular margin. Triradiate ligament upper and lower band shows attachment on anterior part of head of rib to sides of upper and lower vertebra. Middle band shows attachment on intervertebral disc.
3) Costotransverse joint
It is formed by tubercle of a typical rib and transverse process of corresponding vertebra. It is a plane synovial type of joint. Capsular ligament shows attachment on articular margin. Superior costotransverse ligament shows two layers anterior and posterior shows attachment on crest on neck of rib to transverse process of vertebra above. Inferior costotransverse ligament shows attachment on posterior surface neck of rib to transverse process of vertebra. Lateral costotransverse ligament shows attachment on lateral non articular part of tubercle to tip of transverse process of vertebra.
4) Costochondral joint
It is formed by each rib with its cartilage anteriorly. It is a primary cartilaginous type of joint. There is no any movement.
5) Chondrosternal joint
It is formed by medial end of first to seventh costal cartilage and sternum. First chondrosternal joint is primary cartilaginous type of joint. Others are synovial type of joint.
6) Interchondral joint
It is formed in between fifth to ninth costal cartilages. Ninth and tenth costal cartilage is joined with each other by fibrous tissue.
7) Intervertebral joint
It is formed in between body of upper and lower vertebra. It is secondary cartilaginous type of joint. Fibrocartilaginous intervertebral disc is present in between them. This disc shows annulus fibrosus peripherally and nucleus pulposus centrally. Anterior and posterior longitudinal ligaments are present between them.