4. THORAX 3

5. Thoracic Wall 4

6. 5

7. Anterior View Clavicle Sternum Ribs 6

8. Posterior View Vertebrae Scapula 7

9. Surface Landmark Jugular notch Sternal angle Xiphoid process 8

10. Surface Landmark Clavicle Costal margin (costal arch) 9

11. Surface Landmark Sternal angle Nipple 10

12. 11

13. Lines Anterior median line Sternal line Midclavicular line Parasternal line 12

14. Lines 13 Anterior axillary line Midaxillary line Posterior axillary line

15. Lines Posterior median line Paravertebral line Scapular line 14

18. The skeleton of the chest wall is composed of thoracic vertebrae, ribs, and the sternum. The upper limb is attached to the chest wall through the clavicle and indirectly the scapula, which together comprise the shoulder girdle. These structural elements form the framework of the chest and upper limb and are involved in movements of the chest and upper limb as well. The skeleton Structure of the chest wall

19. The chest wall has many important functions. First, the articulations of the ribs, sternum, and vertebral column are central to respiration, because the movements of the ribs result in a cyclic increase and decrease in the volume of air in the lungs. Second, it serves as a protective shield for the thoracic organs. Third, abecause the diaphragm extends superiorly as far as the T5-T6 vertebral level, upper abdominal organs are also protected by the lower part of the ribcage.

20. Movements of the head, neck, upper limbs, and vertebral column all involve muscles with attachments to the chest wall. The chest wall is important for students of anatomy because it is the region where the segmental organization of the body is best illustrated. The T1 vertebra, the two first ribs, and the manubrium of the sternum surround an aperture, known to anatomists as the thoracic inlet (but, paradoxically, to clinicians as the thoracic outlet).

21. This aperture is roughly oval but is indented posteriorly by the body of the T1 vertebra. A similar but much larger aperture is located inferiorly, bounded by the T12 vertebra, ribs 11 and 12, the costal cartilages of ribs 7 to 10, and the xiphoid process. This, at least in anatomical terminology, is the thoracic outlet.

22. vertebrae A vertebra consists of a solid cylindrical body and a posterior semicircular arch of bone that encloses the vertebral canal. Adjacent vertebral bodies are separated by an intervertebral disc, which is strong yet flexible enough to allow considerable mobility of the vertebral column. The posterior arch of bone is composed of a pair of pedicles, a pair of laminae, and a posterior midline spinous process.

23. Thoracic vertebrae are characterized by their slender and downswept spinous processes. The bony transverse processes of thoracic vertebrae are short and protrude laterally and somewhat posteriorly (at about a 30° degree angle). On the transverse processes of thoracic vertebrae 1-10 is a roughly circular facet, a slightly depressed surface intended for articulation with the tubercle of the corresponding rib. This articulation is the costotransverse joint, and it is a typical synovial joint.

24. Ribs 11 and 12 lack costotransverse articulations; thus there are no articular facets on the tubercles of these two ribs nor on the transverse processes of vertebrae T11 and T12. The bodies of all 12 thoracic vertebrae have small articular facets, at which the heads of the ribs articulate with the vertebral bodies. The pattern of articulation, however, is not always a simple "one rib-one vertebra" arrangement. While the heads of ribs 1, 10, 11, and 12 do articulate solely with the body of the vertebra to which they correspond numerically, the heads of ribs 2 to 9 articulate with two adjacent vertebral bodies:

25. (1) the body of the vertebra with which the rib shares a numerical designation and (2) the vertebra just superior to it, in addition to the intervening intervertebral disc (e.g., rib 3 with the bodies of the T2 and T3 vertebrae and the intervening disc). The costovertebral articular surfaces are roughly circular, and the portion of the surface on an individual vertebra is known as a demifacet.

26. Ribs provide structural reinforcement of the thoracic cage so that the chest wall does not collapse as a result of the subatmospheric pressure within the trachea and airways. Most individuals have 12 pairs of ribs, though not uncommonly an extra rib is present or one is missing. Each rib is an elongated curved bone, extending from its vertebral attachments posteriorly around the chest wall to its attachment anteriorly to the costal cartilages. two adjacent vertebral bodies.

34. 33

35. Ribs 3 to 9 share common structural features and are called typical ribs; ribs 1, 2, 10, 11, and 12 have unique structural features and are called atypical ribs. A typical rib (ribs 3 to 9) is in the shape of a half-circle. The shaft of the rib is smoothly curved and contributes to the formation of the lateral thoracic wall. Posteriorly, the head of the rib has two articular facets, meant to articulate with the facets on the The Ribs

36. The tubercle of the rib lies about 3 to 4 cm lateral to the head. The tubercle forms a roughened posterior protrusion on the rib, and part of it is specialized as a facet for articulation with the vertebral transverse process (true for vertebrae T1 to T10; however, vertebrae T11 and T12 lack costo-transverse articulations). The remainder of the tubercle serves as a point of attachment for several ligaments connecting the adjacent ribs.

37. About 6 to 7 cm further lateral along the rib, the rib inclines more sharply in an anterior direction; the point at which this change in the angle of curvature occurs is the posterior angle of the rib. Beyond this, the rib curves much more sharply in an anterior direction. It then sweeps around the lateral body wall, in such a way that the anterior end of the rib lies lower (i.e., more inferior) than its head.

38. Supernumerary ribs are unusual because they occur on cervical or lumbar vertebrae not because their shape is always unusual for a rib. They are often incomplete, however, and may not extend all the way from the vertebral column to the anterior chest.

39. The anterior ends of all the ribs have a facet for articulation with a costal cartilage, a portion of the embryonic rib that fails to develop into bone, as does the rest of the rib primordium. There is no true joint at these costochondral junctions, which are reinforced by ligaments. These costochondral "joints" allow only minor flexibility.

40. Several muscles and ligaments of both the chest and the neck attach to the costal cartilages. Further, medially, the costal cartilages of ribs 1 to 7 (and sometimes 8) articulate with the sternum directly (the sternochondral joints). The first sternochondral joint is cartilaginous, lacking a synovial cavity. The others are usually synovial joints. The costal cartilages of ribs 8 to 10 sweep upward and attach to the costal cartilage of the rib immediately above; those of ribs 11 and 12 are very small and do not attach to the sternum or the adjacent costal cartilages.

47. The sternum The sternum is a composite flattened bone located in the anterior chest wall. Its three parts are the manubrium (composed of bone and located superiorly), the body (composed of bone and located centrally), and the xiphoid process (made up of cartilage and located inferiorly). The xiphoid process generally calcifies through the first several decades of life and appears dense on x-ray of the chest in older adults.

48. Along the superior margin of the manubrium is a midline jugular (sternal) notch, flanked on each side by a curved articular facet for the clavicle. The manubrium has a smooth clavicular articular facet facing directly lateral on each side, into which the medial end of each clavicle fits. While the other joints between the costal cartilages and the sternum are generally synovial, the first sternochondral joint is cartilaginous.

49. Just inferior to the first rib facet, the second costal cartilage articulates with a facet beginning on the inferior margin of the manubrium and extending across to the superolateral margin of the adjacent body of the sternum. The inferior margin of the manubrium is horizontal and smooth and has a thin layer of cartilage forming part of the joint between the manubrium and body of the sternum (known, somewhat confusingly, as the manubriosternal joint). The manubrium and body of the sternum meet each other at an angle, and, as a result, the manubriosternal joint is palpable through the skin as a raised horizontal ridge in the midline of the chest.

50. This is recognized as an important surface anatomy landmark (called the sternal angle or angle of Louis) because the second rib and its costal cartilage are invariably lateral to this ridge, enabling the physician examining a patient to identify all of the ribs by palpation, using the second rib as a starting point. It also lies in the horizontal plane of the lower border of the T4 vertebra, the plane that separates the superior from the inferior mediastinum.

51. The body of the sternum is an elongated plate, which actually forms from the fusion of four different segments or sternebrae. Some evidence of its segmentation may persist as horizontal ridges between the adjacent segments. Its superior margin is horizontal and smooth, forming part of the manubriosternal joint. At the junction of its lateral and superior edges is a small facet which, along with a similar structure on the manubrium, forms an articulation with the second costal cartilage.

52. Shallow facets for costal cartilages 3 to 6 are present along the margins of the body of the sternum. The xiphoid process articulates with the lower margin of the sternal body. The xiphoid is variable in shape. The seventh costal cartilage articulates with the sternum at the joint between the body and xiphoid. The linea Alba (a thickened vertical cord of connective tissue in the midline of the abdominal wall) attaches to the xiphoid process, as do small portions of many large and important muscles-the diaphragm, the rectus abdominis, and the external and internal oblique muscles.

58. Human Anatomy, Larry M. Frolich, Ph.D. THORAX SURFACE ANATOMY Student who cheated in anatomy lab: counted own ribs Males and Females have same number of ribs (no, Eve wasn’t formed from one of Adam’s)

59. Human Anatomy, Larry M. Frolich, Ph.D.

60. BONES BONES STERNUM ◦ manubrium ◦ xiphoid process SCAPULA ◦ spine ◦ medial border ◦ inferior angle RIBS Human Anatomy, Larry M. Frolich, Ph.D.

61. MUSCLES MUSCLES BACK “traps” (trapezius) “lats” (latissimus dorsi) erector spinae (cords in lumber region, great for massage) CHEST “pecs” (pectoralis major) serratus anterior

62. THORACIC WALL 61

63. Thoracic Wall Superficial layer  skin  superficial fascia  breast Deep layer  Deep fascia  Muscles  Intercostal spaces  Internal thoracic vessels and lymph nodes  endothoracic fascia 62

64. Superficial Fascia: ◦ Superficial blood vessels ◦ Lymphatic vessels ◦ Cutaneous nerves 63

65. 64 Anterior cutaneous branches of intercostal n. and perforating branches of internal thoracic a. lateral cutaneous branches of the intercostal n. and lateral cutaneous branches of the posterior intercostal a.

66. BREAST 65

67. The Breast Location: (female breast) ◦ Superior border: 2 nd rib ◦ Inferior border: 6 th rib ◦ Medial border: Sternum ◦ Lateral border: Midaxillary line Location: (male nipple) ◦ Fourth Intercostal Space, Midclavicular line Underlying muscle ◦ Pectoralis major and minor ◦ Part of serratus anterior, external obliques Lateral Thoracic Artery, branches of Internal Thoracic A., Post. Intercostals Intercostal, Internal Thoracic, Axillary Veins Branches of Intercostal Nerve Human Anatomy, Larry M. Frolich, Ph.D.

68. Mammary Glands Mammary Glands Lactiferous (modified sweat) Glands Breast made of 15-25 lobes (each a compound alveolar gland) Lobes made of lobules called acini, alveoli Acini/Alveoli lined w/milk-secreting simple epithelial cells Lactiferous Ducts of lobes open at nipple Areola-ring of pigmented skin around nipple ◦ Sebaceous gland produce sebum during nursing Lobes separated by adipose tissue and suspended by connective tissue = Suspensory Ligaments of the Breasts Human Anatomy, Larry M. Frolich, Ph.D.

69. Mammary Gland Human Anatomy, Larry M. Frolich, Ph.D.

70. BREAST Mammary glands Lactiferous ducts (15 to 20) Nipple 69

71. BREAST Suspensory ligament ( Cooper ligament) Retromammary space 70

72. 71

73. 72

74. Blood Vessels 73 Internal thoracic artery and its perforating branches Lateral thoracic artery Lateral cutaneous branches of the posterior intercostal artery

75. Lymphatic Drainage 74 Apical lymph nodes Pectoral nodes Parasternal lymph nodes Supraclavicular lymph nodes Pathway to the mediastinal lymph nodes

76. Deep Layer Deep fascia Muscles Intercostal spaces Internal thoracic vessels and lymph nodes Endothoracic fascia 75

77. superficial layer Deep fascia deep layer 76

78. 77 Pectoralis major Pectoralis minor Clavipectoral fascia

79. 78

80. Intercostal Spaces: Intercostal muscles Intercostal nerves Intercostal vessels 79

81. 80 External intercostal muscle Internal intercostal muscle Innermost intercostal muscles

82. 81

83. 82 Intercostal nerve Lateral cutaneous branch Anterior cutaneous branch Thoracic spinal nerve

84. Intercostal Nerve Block 1. Costal angle (mostly) 2. Posterior axillary line 3. Anterior axillary line 4. Fracture site 5. Parasternal line 83

85. Intercostal Nerve Block 84

86. 85

87. 86

88. 87

89. Deep Layer Deep fascia Muscles Intercostal spaces Internal thoracic vessels and lymph nodes Endothoracic fascia 88

90. Human Anatomy, Larry M. Frolich, Ph.D. INTERCOSTAL MUSCLES Function in posture, respiration “COSTAL” = ribs “intercostal” = between the ribs

91. Thorax 山东大学医学院 解剖教研室 李振华

92. The muscles of thorax Extrinsic muscles  Pectoralis major  Pectoralis minor  Serratus anterior Intrinsic muscles  Intercostales externi 肋间外肌  Intercostales interni 肋间内肌  Intercostales intimi 肋间最内肌  Transverses thoracis 胸横肌

93. Intercostals external  Origin: lower border of rib above the space)  Insertion: upper border of rib below the space  Action: elevate ribs adding in forced inspiration  Replaced anteriorly by external intercostals membrane. Intercostals interne  Origin: upper border of rib  Insertion: lower border of rib above origin  Action: depress ribs for forced expiration  Replaced posteriorly by internal intercostals membrane.

94. Diaphragm Shape and position : dome-shaped between thorax and abdomen, consists of a peripheral muscular part and a central tendon Origin  Sternal part: xiphoid process  Costal part: lower six and costal cartilages  Lumbar part: arises by two crura from upper 2-3 lumbar vertebrae  Insertion: central tendon Weak areas : triangular spaces without muscular tissue  Lumbocostal triangle: between costal and lumbar parts.  Sternocostal triangle: between costal and sternal parts.

95. Openings in the diaphragm  Aortic hiatus 主动脉裂孔 － lies anterior to the body of the 12th thoracic vertebra between the crura. It transmits the aorta, thoracic duct  Esophageal hiatus 食管裂孔 － for esophagus and vagus nerves at level of T10.  Vena cava foramen 腔静脉孔 － for inferior vena cava, through central tendon at T8 level T8 T10 T12

96. Action :  Contraction: the dome moving downward, increases the volume of thoracic cavity which results in inspiration, at the same time the intra- abdominal pressure is increased assists in defecation, vomiting or child birth.  Relaxation: the dome returns to the former position, reduces the volume to the thoracic cavity, resulting in expiration.

97. Arteries of thorax Pulmonary trunk  Arises from right ventricle  Runs up, back,and to the left  Bifurcates inferior to aortic arch into right and left pulmonary arteries, one for each lung Pulmonary arteries  Right pulmonary artery － passes posterior to ascending aorta and superior vena cava to hilum of right lung  Left pulmonary artery － passes anterior to descending aorta and left main bronchus to hilum of left lung