Heart and Thorax Condensed PDF

Learning Objectives After this lecture students should be able to: 1. Describe the anatomy of the thoracic cage and structures it contains 2. Describe the structures contained within the intercostal spaces 3. Describe the functional anatomy of the pleura 4. Describe the anatomy of the lungs 5. Descr...

Learning Objectives After this lecture students should be able to: 1. Describe the anatomy of the thoracic cage and structures it contains 2. Describe the structures contained within the intercostal spaces 3. Describe the functional anatomy of the pleura 4. Describe the anatomy of the lungs 5. Describe the functional anatomy of respiration Thorax – introduction Dr. Ernie Jennings 1 2 Articulations Organisation Skeletal protection Muscular movement 3 4 Overview Overview • 3 internal compartments • Central mediastinum (+ heart)- next lecture • Left pleural cavity (+ lung) • Right pleural cavity (+ lung) Fig 3.100 Gray’s Anatomy for students 2nd Ed 5 6 Relationship to other Regions: Neck Internal Orientation • Diaphragm movement changes thoracic volume • Creates basis for inspiration / expiration 7 8 Diaphragm Diaphragm Fig 3.15 Gray’s Anatomy for students 2nd Ed 9 10 Diaphragm Phrenic n Muscles of the thoracic wall and pleurae Int thoracic a Central tendon IVC-T8 Dr. Ernie Jennings oesophagus-T10 +vagus (X) Aortic hiatus-T12 Phren (Gk) = diaphragm or mind Fig 3.33 Gray’s Anatomy for students 2nd Ed 11 12 Muscles- thoracic cage Pleura Similar to muscle layers in superficial abdominal wall Two pleural cavities surround the lungs- one either side of the mediastinum Parietal- innervated by branches of costal nerves. VisceralNormally separately by a thin layer of serous fluid Fig 3.35 Gray’s Anatomy for students 2nd Ed 13 Pleura Pleura Parietal pleura (on thoracic wall - line pleural cavities) Pleural space 14 • Pleurae line the lung (visceral) and the pulmonary cavities (where the lungs sit) and is one continuous serous sac. • The pleura are separated by a Continuous at lung “potential” space which contains root (hilum of lung) serous fluid. Visceral pleura (on lung) • Fluid aids movement and helps creates surface tension which keeps the lung inflated.*there are also internal negative pressures which aid this that you will cover in later weeks* Lungs Lungs Fig 3.38 Gray’s Anatomy for students 2nd Ed Contents Ligament Nerves – relations 17 Right Lung Fig 3.40 Gray’s Anatomy for students 2nd Ed 18 Left Lung Fig 3.41 Gray’s Anatomy for students 2nd Ed 19 Fig 3.42 Gray’s Anatomy for students 2nd Ed 20 Bronchial tree Functional anatomy of respiration Dr. Ernie Jennings Fig 3.43 Gray’s Anatomy for students 2nd Ed 21 22 Function Structure of a Typical True Rib • • • • The heads of most ribs articulate through two facets – one joins with the body of the same-numbered thoracic veretebra, whilst the other articulates with the superior vertebra The shaft of the rib extends to the costal cartilages – secure but flexible attachment to the sternum The first pair of ribs are atypical – are flattened (superior to inferior) and are quite broad – support the blood vessels that serve the upper limbs Ribs 1 and 10-12 articulate with only one vertebral body Fig 3.24 Gray’s Anatomy for students 2nd Ed 23 24 Movements: Bucket Handle Movements: Pump Handle 25 Accessory Muscles: Inspiration • Diaphragm 26 Accessory Muscles: Expiration • Abdominal wall muscles (primary) • Scalene muscles • Sternocleidomastoid • Internal intercostals • External Intercostals • Passive recoil of lungs 27 28 Muscles- thoracic cage Similar to muscle layers in superficial abdominal wall Thorax – neurovascular supply Dr. Ernie Jennings 29 Segmental Supply 30 Segmental Supply Fig 3.29 Gray’s Anatomy for students 2nd Ed 31 Fig 3.30 Gray’s Anatomy for students 2nd Ed 32 Segmental Supply Lymphatics Fig 1.29 Gray’s Anatomy for students 2nd Ed Fig 3.94 Gray’s Anatomy for students 2nd Ed 33 Lymphatics 34 Lymphatics Fig 3.31 Gray’s Anatomy for students 2nd Ed Fig 1.30/31 Gray’s Anatomy for students 2nd Ed 35 36 Segmental Supply Lymphatic filariasis https://www.amnh.org/explore/science-topics/science-topicdisease-eradication/countdown-to-zero/lymphatic-filariasis http://focal-ntds.org/wp-content/uploads/2016/06/LF_slider.png 37 Thoracic Nerves / Intercostal nerves 38 Q1. In the post COVID era you are invited to a family birthday party and are asked to blow up balloon. Briefly describe which muscle are necessary for forced exhalation. (2 marks) 39 40 Q2. Henry Dangerfield is 78 year regular patient. He says that since his last check up he has an angioplasty and stent inserted into his anterior interventricular artery. Cardiovascular system Describe the passage of blood from the left ventricle into the anterior interventricular artery. (2 marks) Dr. Ernie Jennings 41 Organisation Learning Objectives • • • • • 42 Understand the gross anatomy of the heart, direction of blood flow and names of the major structures. Describe the structure of the structure and function of valves Understand where the heart sits in the thorax and what its relations are. Recall the major veins draining into the heart and major arteries originating from the aorta. Describe the arterial supply and venous drainage of the heart. Pulmonary circulation NB: -Arteries take blood away from heart. -Veins bring blood towards heart 43 Systemic circulation 44 Organisation Location of Heart • 2 Halves (Left & Right) • 4 Chambers • 2 Atria (atrium) - collecting chambers • 2 Ventricles - pumping chambers 45 46 Formation of Heart Formation of Heart • Final orientation of muscle is important for contractions to be able to control direction of flow. • Heart folds & twists in development. 47 48 Intrinsic conducting system Structure of the heart Dr. Ernie Jennings 49 Pericardium: Serous 50 Pericardium: Fibrous Attached to outer surface of serous. Tough and fibrous: fibrous pericardium • Covers heart (visceral) and lines fibrous pericardial sac (parietal): pericardial cavity contains serous fluid 51 52 Heart Wall Adult Orientation 53 Atria 54 Adult Orientation Thin walled collecting chambres. Smooth walled area Ridged muscular area Septal area 55 56 Ventricles- & valves Adult Orientation Right border = right atrium Base = left and right atria semilunar Left border = left ventricle Apex = left ventricle 57 58 Heart Fibrous Skeleton Heart valves Dr. Ernie Jennings 59 60 Heart Valves Heart Valves and Sounds • Valves all lie behind body of sternum 61 62 Cuspid valves Valve Arrangement • Cusps attach to chordae tendineae → papillary muscles 63 64 Semilunar Valve Action - Open Cuspid valve action 65 66 Semilunar Valve Action - Closed Heart- neurovascular supply Dr. Ernie Jennings 67 68 Coronary Arteries Fig 3.71 Gray’s Anatomy for Students (2nd Ed) Coronary Arteries 69 Coronary Vessels Fig 3.74 Gray’s Anatomy for Students (2nd Ed) 70 Great Vessel- embryology 71 72 Great Vessel- embryology Superior mediastinum 73 Relations 74 Summary • Right and left phrenic nerves (C3, 4,5) pass anterior to lung root • Right and left vagus (X) pass posterior to lung root • Note relationship of nerves to the heart chambers 75 78