Thorax and Contents Part 2 Flashcards
What are sternal ribs?
Ribs that attach to the strernum (ribs 1-9)
What are asternal ribs?
caudal to the sternum, (ribs 10-13)
Costal arch
united costal cartilages of ribs 10-12
What is the floating rib?
13th rib, fails to make contact with costal arch, instead ends freely in flank
Boundaries of Thoracic Cavity
Cranial - Thoracic Inlet Dorsal - Thoracic Vertebral bodies Ventral - sternum Caudal - diaphragm Lateral - ribs, costal cartilages, & intercostal muscles
Boundaries of Thoracic Inlet
Dorsal - body of 1st thoracic vertebra
Lateral - 1st pair of ribs and their costal cartilages
Ventral - 1st sternebra (manubrium)
Contents found in Thoracic Cavity
Trachea Lungs Heart Thymus Esophagus Lymph Nodes Vessels Nerves Pleural Cavities Pericardial Caivty
Contents of Thoracic Inlet
Trachea Esophagus Vagosympathetic nerve trunk Recuurent laryngeal nerves Phrenic nerves Ventral branches of 1st and 2nd thoracic spinal nerves Several blood vessels Pleural Cupulae
Thoracic Outlet (Diaphragm)
Lumbocostal Arch
Aortic Hiatus
Esophageal Hiatus
Caval Foramen
What is pleura?
Mesothelial membrane which lines the thoracic cavity, encloses the mediastinum, and covers the lungs
Mediastinum
- Midline partition of thorax
- includes 2 mediastinal pleura and the space between them
- encloses thymus, lymph nodes, heart, aorta, trachea, esophagus, nerves, & vessels
Pleural Cavities
- surround lungs (balloon analogy)
- contain only a small amount of serous fluid in healthy individuals
Visceral Pleura
pulmonary pleura
Parietal Pleura
- costal pleura
- mediastinal pleura
- diaphragmatic pleura
Connecting Pleura
ligaments and folds
T/F: The canine mediastinum is not easily ruptured.
False. The canine mediastinum is easily ruptured, often allowing communication between both pleural cavities.
Parts of Left Lung
Cranial & Caudal Lobes
Cranial Lobe has cranial and caudal parts
Parts of Right Lung
4 Lobes
- Cranial
- Caudal
- Middle
- Accessory
Where is the cardiac notch?
What is its significance?
Location: right 4th-5th intercostal space
Significance: Can access heart w/o hitting the lung
Order of bronchi as drawing in a breath
primary (principal) -> secondary (lobar) -> tertiary (segmental)
What is the carina?
Midline cartilaginous crest where trachea divides into right & left bronchi
Which blood supply feeds the lungs?
Nutritional Blood Supply
- Bronchoesophageal artery (from the right 5th intercostal artery)
Which blood supply takes blood to the lungs for gas exchange?
Functional Blood Supply
- Pulmonary Arteries (from pulmonary trunk)
- cary nonaerated blood from the right ventricle of heart to lungs for gas exchange
Define the auscultation triangle for the lungs
- Caudal border of triceps brachii
- Lateral edge of epaxial muscles (horizontal line from caudal angle of scapula to tuber coxae)
- Line paralleling basal border of lungs (sternal end of 6th rib to 11th intercostal space)
What is the potential space where the diaphragmatic and costal parietal pleura are in contact with one another?
Costodiaphragmatic recess
What is the pericardium?
fibroserous covering of the heart
- Serous pericardium
- Fibrous pericardium
Serous pericardium
- mesothelial sac enclosing the pericardial cavity
- divided into parietal and visceral layers
Fibrous pericardium
fibrous CT covering the parietal layer of the serous pericardium
Pericardial Sac
composite structure consisting of 3 layers which surrounds the pericardial cavity
What happens when excessive fluid builds up in the pericardial sac?
compression of the heart
Lumbocostal Arch
Sympathetic Trunk & Major Splanchnic Nerve
Aortic Hiatus
Aorta, Azygos Vein, & Thoracic Duct
Esophageal Hiatus
Esophagus, Dorsal & Ventral Vagal Trunks
Caval Foramen
Caudal Vena Cava
