Anatomy: Thorax, Mediastinum, and Body Cavities Flashcards
What are the subdivisions of the Ventral Body Cavity?
Cranial Cavity, Dorsal body cavity, vertebral cavity, thoracic cavity, abdominal cavity, and pelvic cavity
Viscera is covered with what?
Serous membrane
What are the two parts to the serous membrane?
Parietal layer and Visceral layer
What does the Parietal layer do?
line the walls of the cavity
What does the Visceral layer do?
Adheres to the surface of the organ
What does the small layer of serous fluid between parietal and visceral layer do?
Reduces friction
What are the serous membranes based on location?
Parietal pleura/visceral pleura, parietal pericardium/visceral pericardium, parietal peritoneum/visceral peritoneum
Where does the thorax span from?
From the neck to the diaphragm
What does the thorax consist of?
A wall, two pleural cavities, lungs, and mediastinum
The thorax houses and protects what?
The heart, lungs, and great vessels
What are the thorax functions?
Conduit for structures passing from neck to abdomen. Principle role in breathing, support for upper limbs
What are the three flat muscles found in each intercostal space that pass between ribs?
External intercostal muscle, internal intercostal muscle, innermost intercostal muscle
What do the intercostal muscles of the thorax do?
All assist in respiration
What is the diaphragm?
Major respiratory muscle that separates thoracic and abdominal cavity and is innervated by the phrenic nerve (C3-5)
What structures pass through the diaphragm?
Inferior vena cava (T8), Esophagus (T10), Aorta (T12)
What are the arteries of the Thoracic wall?
Internal thoracic artery, anterior intercostal artery, posterior intercostal artery, musculophrenic artery
What artery does the internal thoracic artery branch off of?
subclavian artery
Where does the posterior intercostal artery branch off of?
aorta
Both the anterior intercostal artery and the musculophrenic artery branch off of what?
Internal thoracic artery
Most veins of the thorax drain into what?
Azygos vein
Where is the azygos vein located?
right side of the posterior thoracic wall and drains into superior vena cava
What is the Mediastinum?
Broad, central partition separating the two pleural cavities
Where does the Mediastinum extend from?
Sternum to bodies of vertebrae and superior aperture to diaphragm
What is the Mediastinum divided into?
Superior mediastinum, anterior mediastinum, middle mediastinum, and posterior mediastinum
What are the contents of the mediastinum?
Thymus gland, brachiocephalic vein, superior vena cava, aortic arch & 3 branches, trachea, espohagus, phrenic nerve, thoracic duct & lymphatics, pericardium & heart, nerve plexus, azygos vein, sympathetic chain, vagus nerve, fat
