Thorax Flashcards
What are the origins of the dorsal and ventral intercostal arteries?
- dorsal: first 3 come from branch of costocervical trunk, remaining 9 come from aorta
- ventral: come from internal thoracic artery, and join with the dorsal intercostal arteries
What are the muscular parts of the diaphragm?
- right and left costal parts: attaches to ribs
- sternal part: attaches to sternum
- lumbar part: left and right crura attach to vertebral bodies of L3 and L4
Name the openings in the diaphragm and the structures that pass through them
- aortic hiatus: (between crura) aorta, azygos vein, and thoracic duct
- esophogeal hiatus: (muscular part of right crus) esophagus, vagal nerve trunks, and esophageal vessels
- caval foramen: (right side) caudal vena cava
What is the Endothoracic fascia?
underlying connective tissue that attaches the pleura to the thoracic walls
What is the parietal and visceral pleura?
- parietal: where the two pleural sacs are adherent to the walls of the thoracic cavity and mediastinum
- visceral: adherent to the surface of the lungs, continuous with parietal
What is the pulmonary ligament and the phrenicopericardial ligament?
- pulmonary: a fold of pleura that connects the caudal lobe of the lung to the mediastinum
- phrenicopericardial: formed by the continuation of the fibrous pericardium to the sternum and diaphragm
Name the recesses within the pleural cavity
- pleural cupula
- costomediastinal recess
- costodiaphragmatic recess
- mediastinal recess
What is the diaphragmatic line of pleural reflection?
junction between the costal pleura and diaphragmatic pleura
- caudal to this line, the diaphragm is directly attached to the thoracic wall, and the abdominal cavity may be approached without risk to the pleural cavity
What is the plica vena cavae?
a loose fold of pleura derived from the right caudal mediastinal portion of the pleural sac that surrounds the caudal vena cava and right phrenic nerve
Describe the course of the thoracic duct
- arises from cisterna chyli
- enters mediastinum via aortic hiatus
- runs cranially on dorsal border of aorta
- crosses ventral surface of fifth thoracic vertebra
- terminates on left brachiocephalic vein
Describe the course of the vagus nerves
- left and right vagus nerves leave the vagosympathetic trunk
- left and right recurrent laryngeal nerves branch off
- vagus nerves split into dorsal and ventral branches past the base of the heart
- the ventral branches unite to form the ventral vagal trunk, and the dorsal branches unite to form the dorsal vagal trunk
- travel with esophagus to the abdominal cavity
Describe the course of the left and right phrenic nerves
- arise from the ventral branches of cervical nerves 5-7
- pass through thoracic inlet, then mediastinum, and innervate the diaphragm
- right phrenic utilizes the plica vena cavae
- left phrenic occupies ventral part of caudal mediastinum
What are the branches of the ascending, arch, and descending aorta?
- ascending: right and left coronary arteries supply the heart
- arch: brachiocephalic trunk (gives rise to right and left carotid aa., and right subclavian a.) and left subclavian a.
- descending: dorsal intercostal aa., esophageal and bronchial aa., and bronchoesophageal a.
What are the branches of the subclavian artery?
- vertebral artery
- costocervical trunk
- superficial cervical artery
- internal thoracic artery
Describe the veins that lead into the cranial vena cava (what forms it?)
the external jugular veins join with the subclavian veins to form the brachiocephalic veins, which join together and form the cranial vena cava
