Thoracic Cage and

Professor Dr. Mario Edgar Fernández.

Parts of the body The

Is the part of the trunk betwen the and abdomen. Commonly the term chest is used as a synonym for thorax, but it is incorrect. Consisting of the , its contents, and the wall that surrounds it. The thoracic cavity is divided into 3 compartments:  The central mediastinus.  And the right and left pulmonary cavities.

Thoracic Cage

The thoracic skeleton forms the osteocartilaginous thoracic cage. Anterior view. Thoracic Cage

Posterior view.

Summary: 1. of thoracic cage: (, , and ). 2. of thoracic cage: (intervertebral joints, , and ) 3. Movements of thoracic wall. 4. Thoracic cage. Thoracic apertures: (superior thoracic aperture or thoracic inlet, and inferior thoracic aperture).

Goals of the classes

 Identify and describe the bones of the thoracic cage.

 Identify and describe the joints of thoracic cage.

 Describe de thoracic cage.

 Describe the thoracic inlet and identify the structures passing through.

Vertebral Column or Spine

 7 cervical.  12 thoracic.  5 lumbar.  5 sacral  3-4 coccygeal Vertebrae

That bones are irregular, 33 in number, and received the names acording to the position which they occupy. The vertebrae in the upper 3 regions of spine are separate throughout the whole of life, but in sacral anda coccygeal regions are in the adult firmly united in 2 differents bones: and .

Thoracic vertebrae Each vertebrae consist of 2 essential parts:  An anterior solid segment: vertebral body.  The arch is posterior an formed of 2 pedicles, 2 laminae supporting 7 processes, and surrounding a . Thoracic vertebrae

The body is the largest part of the . Above and bellow, it is flattened. Its upper and lower surface are rough, for the attachment of the intervertebral fibro- . In front , it is convex from side to side, concave from above downwards. Thoracic vertebrae

The thoracic vertebrae may bee at once recognised by the presence on the sides of the body of 1 or more half-facets for the heads of the ribs. Thoracic vertebrae

The pedicles are 2 short, thick pieces of , which projet backwards. Thoracic vertebrae

The concavities above and below the pedicles are the intervertebral notches, they are 4 in number, 2 on each side. The inferior ones being generally the deeper. Thoracic vertebrae

When the vertebrae are articulated, the notches of each contigous pair of bones form the intervertebral foramina, which communicate with the and transmit the spinal nerves and blood- vessels. Thoracic vertebrae

 The laminae are 2 broad plates of bone which complete the neural arch by fusing together in the middle line behind. Thoracic vertebrae

 The laminae enclose a foramen, the vertebral or spinal foramen, which serves for the protection of the , and are connected to the body by means of the pedicles. Thoracic vertebrae

The spinous process projects backwards from the junction of the 2 laminae, and serve s for attachment of muscles and , Thoracic vertebrae

 The spinous processes are long, triangular on transverse section, directed obliquely downwards, and terminate in a tubercular extremity. Thoracic vertebrae

The , 4 in number, 2 on each side, spring from the junction of the pedicles with the laminae. Thoracic vertebrae

 The articular processes are flat, nearly vertical in direction, the superior being directed backwards and a little outwards and upwards. The inferior forwards and a little inwards and downwards. Thoracic vertebrae

 The transverse processes, 2 in number, project one at each side from the point where the lamina joints the pedicle, betwen the superior and inferior articular processes. Thoracic vertebrae

 The transverse processes are thick, strong, and considerable length, directed obliquely backwards and outwards, presenting a clubbed extremity, which is tipped on its anterior part by a small, concave surface, for the articulation with the tubercle of a . Thoracic vertebrae Peculiar thoracic vertebrae:  First dorsal vertebra.  Tenth dorsal vertebra.  Eleventh dorsal vertebra.  Twelfth dorsal vertebra. Thoracic vertebrae

Peculiar thoracic vertebrae: - TI bears a complete superior for the head of the first rib and an inferior costal demifacet for the head of the second rib. -TX only has a superior costal demifacet. -TXI-XII express complete costal facets for the ribs with the same number. They have no costal facets on their transverse processes.

Ribs.  There are 12th pair of ribs.  All 12 attach posteriorly to .  Pairs 1th-7th are true ribs (attach directly to the sternum by costal cartilages).  Pairs 8th-10th are false ribs ( attach undirectly to the sternum).  Pairs 11th and 12th are floating ribs. Ribs.

Each rib presents 2 extremities, a posterior or vertebral, an anterior or sternal, and an intervening portion (the body or shaft) Ribs.

The posterior or vertebral extremity presents for examination a head, neck, an tuberosity or tubercle. Ribs.

The shaft is thin and flat, so as to present 2 surfaces, an external and an internal. Ribs.

The anterior or sternal extremity is flattened, and presents a porous, oval, concave depression, into which the costal is received. Ribs. Ribs. Peculiar ribs:  The 1st rib.  The 2nd rib.  The 10th rib.  The 11th rib.  The 12tth rib. The sternum. Is a flat, narrow bone situated in the median line of the front of the chest, and consisting, in the adult of 3 portions.it has been likened to an ancient sword. The sternum.

The 1st portion of the sternum, or manubrium is somewhat triangular form The sternum.

The 2nd piece of the sternum, the body also called gladiolus, considerably longer than the 1st piece, is broader below than above. The sternum.

The 3rd piece of the sternum, xiphoid appendix, is the smallest of the3, it is thin and elongated in form. Sternum.

3 parts: Manubrium, Body * . Manubrium: Lies opposite T3,4. Body: T5 toT8 Xiphoid T9

Articulations betwen thoracic vertebrae

Joints of the vertebral Joints of the vertebral bodies. arches.  .  Zygap0physial joints.  The anterior  . longitudinal .  Interspinous ligaments.  The posterior  Supraspinous ligaments. longitudinal ligament.  Intertransverse ligaments. Articulations betwen thoracic vertebrae

 Zygapophysial .  IV disc. Articulations betwen thoracic vertebrae

 Ligamenta flava.  .  IV disc. Articulations betwen thoracic vertebrae

 Posterior longitudinal ligament.  Anterior longitudinal ligament.

Costovertebral joints

 Joints of head of ribs.  Costotransverse joints.

Sternocostal joints

Manubriosternal and xiphisternal joints: synchondroses, with age they become ossified.

Sternocostal joints: Rib I: Ribs II-VII: synovial joints

Intercostal joints: Ribs VI-X synovial joints

Movements of thoracic wall Thoracic cage.

Functions:  Protects vitals organs within the thorax.  Supports thorax during respiration.  Supports shoulder girdles and upper limbs.  Provides attachments points for back, chest, and shoulder muscles.

Lines of orientation.

 Midsternal line.  Midclavicular line.  Anterior axillary line.  Posterior axillary line.  Midaxillary line.  Scapular line. Surface lanmarks.

 Jugular notch  : Marks rib 2 Lies at level of T4-5 IV disc  Apex heart beat: Left IC space 5; midclavicular line  Aortic valve: Right IC space 2

Surface lanmarks.

 Infrasternal angle: Important in CPR. Depression between is the Infrasternal fossa.  :within the fossa is at the level of the body of T9. Surface lanmarks.

 Pulmonary valve Left IC space 2  Tricuspid valve Right IC space 5  Bicuspid valve Left IC space 5  Bifurcation of Vertebral level T4-5

Surface lanmarks.

 Posterior thorax: scapula: Scapular spine is at level of 3rd rib and T2 vertebra. Inferior scapular angle is at the level of the 7th rib, the spine of T7 or the body of T9.  : Superior part is marked by the 7th cartilage. Inferior part is marked by the 10th cartilage

Structure of thoracic cage.  Twelve thoracic vertebrae.  Twelve pairs of ribs and their costal cartilages.  Sternum.  Intercostal muscles.

Thoracic inlet (superior thoracic aperture)  First thoracic vertebra.  First pair of ribs and costal cartilages.  Manubrium.

Thoracic outlet (inferior thoracic aperture)  Twelfth thoracic vertebra.  Twelfth pair of ribs and costal cartilages.  Xiphisternal joint. Thorax RX.

Espacio Costillas. intercostal. Bibliography.  Grays anatomy: the anatomical basis of clinical practice.  Grays anatomy; anatomy descriptive and surgical.  Clinically oriented anatomy: Keith L. Moore.