1 A-THE THORACIC WALL A-THE THORACIC WALL Boundaries Boundaries Posteriorlyby the thoracic part of the vertebral columnPosteriorlyby the thoracic part of the vertebral columnAnteriorlyby the sternum and costal cartilagesAnteriorlyby the sternum and costal cartilagesLaterallyby the ribs and intercostal spacesLaterallyby the ribs and intercostal spacesSuperiorlyby the suprapleural membraneSuperiorlyby the suprapleural membraneInferiorlyby the diaphragm, which separatesthe thoracic cavity from the abdominal cavityInferiorlyby the diaphragm, which separatesthe thoracic cavity from the abdominal cavity
2 Divides into three parts: 1- STERNUMIt is a flat boneDivides into three parts:1-Manubrium sterni2-Body of the sternum3- Xiphoid process
3 second costal cartilage The sternal angle(angle of Louis)formed by the articulation of the manubrium with the body of the sternumLies at the level ofsecond costal cartilageThe point from which all costal cartilages and ribs are counted
4 2-RibsThere are 12 pairs of ribs, all of which are attached posteriorly to the thoracic vertebrae.The ribs are divided into three categories according to their relation to the sternum:True ribs: The upper seven pairs are attached anteriorly to the sternum by their costal cartilagesFalse ribs: The 8th, 9th, and 10th pairs of ribs are attached anteriorly to each other and to the 7th rib by means of their costal cartilages.Floating ribs: The 11th and 12th pairs have no anterior attachment
5 A rib has a head, neck, tubercle, shaft, and angle Typical RibA typical rib is a long, twisted, flat bonehaving a rounded, smooth superior borderanda sharp, thin inferior borderThe inferior border formsTHE COSTAL GROOVEwhich accommodates the intercostal vessels and nerve.intercostal veinintercostal arteryintercostal nerveVANimportantA rib has a head, neck, tubercle, shaft, and angle
6 (fused to form the sacrum) (the lower 3 are commonly fused) 3-The Vertebral Columnis composed of 33 vertebrae7 cervical12 thoracic5 lumbar5 sacral(fused to form the sacrum)4 coccygeal(the lower 3 are commonly fused)
7 2-a vertebral arch posteriorly. (protect the spinal cord) A typical thoracic vertebra consists of:1-a rounded body anteriorly (body bearing)2-a vertebral arch posteriorly.(protect the spinal cord)They enclose a space calledThe vertebral foramenthrough which run the spinal cord and its coveringsThe vertebral arch gives riseto seven processes:a-One spinousb-Two transversec- Four articular(2 superior 2 inferior)
8 Characteristics of a Typical Thoracic Vertebra The body is heart shapedThe vertebral foramen is small and circularThe spines are long and inclined downwardCostal facets are present on the sides of the bodies for articulation with the heads of the ribsCostal facets are present on the transverse processes for articulation with the tubercles of the ribs
9 The body and the vertebral arch are connected by means of pedicles
10 upper and lower borders the superior and inferior The pediclesare notched on theirupper and lower bordersFormingthe superior and inferiorvertebral notches.On each sidethe superior notch of one vertebra and the inferior notch of an adjacent vertebra together form an intervertebral foramen.These foramina, in an articulated skeleton, serve to transmit the spinal nerves and blood vessels.
11 4-The diaphragmThe diaphragm is a thin muscular and tendinous septum that separatesthe chest cavity abovefromthe abdominal cavity belowThe diaphragm is the most important muscle of respiration.It is dome shaped and consists of aperipheral muscular partand a centrally placed tendon
12 passes through the central tendon at approximately vertebral Main Openings in the diaphragmThe inferior vena cavapasses through the central tendon at approximately vertebrallevel T8The esophaguspasses through the muscular part of the diaphragm, approximately at vertebrallevel T10The aorta passes behind the posterior attachment of the diaphragm at vertebrallevel T12
13 Nerve supply of the diaphragm The phrenic nerves
14 INTERCOSTAL VEIN INTERCOSTAL ARTERY INTERCOSTAL NERVE (VAN) 5-Intercostal Spaces1-SKIN2-SUPERFISCIAL FASCIA3- THREE MUSCLES OF RESPIRATION:THE EXTERNAL INTERCOSTALTHE INTERNAL INTERCOSTALTHE INNERMOST INTERCOSTAL MUSCLE4-THE ENDOTHORACIC FASCIA5-THE PARIETAL PLEURA.The intercostal nerves and blood vessels run betweenthe intermediate (internal intercostal) and deepest layers (innermost intercostal) of musclesThey are arranged in the following order from above downward:INTERCOSTAL VEININTERCOSTAL ARTERYINTERCOSTAL NERVE(VAN)
15 Its fibers are directed The external intercostal musclethe most superficial layer.Its fibers are directeddownward and forwardThe Internal Intercostal Muscleforms the intermediate layer.Its fibers are directeddownward and backward
16 The innermost intercostal muscle Forms the deepest layerIt is an incomplete muscle layer and crosses more than one intercostal space within the ribs.
17 B-CHEST CAVITYThe chest cavity is bounded by the chest wall and below by the diaphragm
18 The chest cavity can be divided into MEDIAN PARTITIONCALLEDTHE MEDIASTINUMLATERALLY PLACED PLEURAE AND LUNGS
19 2-PleuraeThe pleurae and lungs lie on either side of the mediastinum within the chest cavityFORMATION OF THE LUNGSEach lung bud invaginates the wall of the cavity and then grows to fill a greater part of the cavitythe lung is covered with visceral pleura and the thoracic wall is lined with parietal pleuraThe original cavity is reduced to a slitlike space called the pleural cavity as a result of the growth of the lung.
20 1- Parietal layer, which lines Each pleura has two parts:1- Parietal layer, which linesA-The thoracic wall2- Visceral layer:completely covers the outer surfaces ofThe lungs
21 The Pleural Cavity The parietal and visceral layers of pleura are separated from one anotherby a slit like spaceThe Pleural Cavity
22 The trachea is a mobile cartilaginous and membranous tube It begins in the neck as a continuation of the larynx at the lower border of the cricoid cartilage at the level of the sixth cervical vertebraends at the carina by dividing into right and left principal (main) bronchi at the level of the sternal angle (opposite the disc between the fourth and fifth thoracic vertebrae).
23 The right principal (main) bronchus 3- more vertical than the left Principal BronchiThe right principal (main) bronchus1-wider2-shorter3- more vertical than the left4-is about 1 in. (2.5 cm) longThe left principal (main) bronchus is1-narrower2-longer3-more horizontal than the right4- is about 2 in. (5 cm) long.
24 INHALED FOREIGN BODIES the right instead of the left bronchus Inhalation of foreign bodies into the lower respiratory tract is common, especially in childrenBecause the right bronchus is the wider and more direct continuation of the trachea foreign bodies tend to enterthe right instead of the left bronchus
25 Each lung is conical, covered with visceral pleura LungsIn the child, they are pink, but with age, they become dark because of the inhalation of dust particles that become trapped in the phagocytes of the lung.The lungs are situated so that one lies on each side of the mediastinum.Each lung is conical, covered with visceral pleura
26 At about the middle of mediastinal surface is the hilum Each lung has a blunt apex, which projects upward into the neck for about 1 in. (2.5 cm) above the claviclea concave base that sits on the diaphragma convex costal surface, which corresponds to the concave chest walla concave mediastinal surface, which is molded to the pericardium and other mediastinal structuresAt about the middle of mediastinal surface is the hiluma depression in which the bronchi, vessels, and nerves that form the root enter and leave the lung.The anterior border is thin and overlaps the heartThe posterior border is thick and lies beside the vertebral column
27 the oblique and horizontal Right LungThe right lung isslightly larger than the leftis divided bythe oblique and horizontalfissures into three lobes:THE UPPERMIDDLELOWER LOBES
28 The left lung is divided by a similar oblique fissure into two lobes: the upper and lower lobes There is no horizontal fissure in the left lung
29 For the Practical sessions you do need to recognize the following superior1-Pulmonary arterySuperiorin positionFor the Practical sessions you do need to recognize the following(1, 2 & 3) according to their anatomical positions3-Main bronchusPosteriorin position2-Pulmonary veinsInferiorin positionposterioranteriorinferior