Lecture 9 (mediastinum) pt 1 Flashcards
Including heart; 10.24 lecture
How does blood enter and exit the left side of the heart?
Enter: Pulmonary veins
Exit: Aorta
How does blood enter and exit the right side of the heart?
Enters: SVC and IVC
Exits: Pulmonary artery
Thoracic cavity surrounded by the thoracic wall, diaphragm to superior thoracic aperture. What are the two cavities within it?
1) Central mediastinal cavity
2) Right and left pulmonary cavities
What is within the central mediastinal cavity?
Pericardium, pericardial cavity, heart & great vessels, trachea, esophagus
What two things are within the right & left pulmonary cavities?
Lungs and the pleural cavities
What two things make up the pleural cavities? Describe what each covers and reflects
1) Parietal pleura: covers walls, diaphragm & reflects onto the root of the lungs and mediastina
2) Visceral pleura: covers viscera and reflects into the fissures
1) What is the central compartment of the thoracic cavity?
2) What pleura are found here?
3) What thoracic viscera does this compartment contain?
1) Mediastinum
2) Mediastinal pleura
3) All the viscera in thorax except lungs
What are the inferior and superior borders of the mediastinum called? What makes up the inferior part?
1) Superior thoracic aperture
2) Inferior thoracic aperture: diaphragm
The sternum/costal cartilage of the mediastinum are found ____________________ to thoracic vertebral bodies
anteriorly
1) Where are the anterior and posterior boundaries of the superior mediastinum?
2) Where is the transverse thoracic plane?
1) Superior thoracic aperture (first rib, clavicle, & jugular notch) to sternal angle anteriorly; to T5 posteriorly.
2) Runs anterior-posterior horizontally, from sternal angle anteriorly to superior endplate of T5 posteriorly
1) What are the boundaries of the inferior mediastinum?
2) What further divides the inferior mediastinum?
1) Transverse thoracic plane superiorly, to diaphragm
2) Pericardium
What are the 3 divisions of the inferior mediastinum, and what do they contain?
1) Anterior mediastinum: clear space
2) Middle mediastinum: heart
3) Posterior mediastinum: esophagus and descending thoracic aorta
True or false: apex of lungs extends above clavicles
True
Why is the diaphragm higher on the right side?
To make room for the liver
Describe the esophageal plexus of nerves:
1) What is it made up of?
2) What does it modulate?
1) Made up of postsynaptic sympathetic and presynaptic parasympathetic fibers
2) Gives branches to the esophagus to modulate the enteric nervous system (smooth muscles of GI viscera)
What does the cardiopulmonary plexus supply?
Where does it go?
1) To the heart itself and smooth muscles of airways
2) Follow vessels through the hilum as part of the root of the lung
What does the vagus nerve do once it gives off the left and right recurrent laryngeal nerves? (3 things)
1) Forms net around trachea as a part of pulmonary plexus and around esophagus as part of esophageal plexus
2) Then anterior and posterior vagus nerves form vagal trunk at the esophageal hiatus (along with sympathetic fibers)
3) Goes into esophagus, bronchial smooth tissue, and cardiac muscle
What does the pericardium fuse with?
Tunic adventitia
What is the pericardium (pericardial sac)?
What does it enclose? (2 things)
Double walled fibro-serous membrane that encloses:
1) Heart
2) Roots of the Great vessels (fuses with tunica adventitia)
(similar to pleura enclosing the lungs)
1) What is the outside layer of the pericardial sac? What does it blend with?
2) What is the internal surface of the external layer made of? What is it also called?
3) What is it reflected on the heart and great vessels as?
1) Fibrous (external layer) pericardium; blends with central tendon.
2) Serous membrane; parietal layer of serous pericardium
3) Visceral layer of serous pericardium
What are the two layers of the serous (inner) layer of the pericardial sac, and what are they attached to?
What is between them?
1) Outer parietal layer: adhered to the fibrous layer
2) Inner visceral layer: adhered to the heart, aka epicardium
Pericardial cavity is between them
What is the visceral layer of the pericardium also called?
Epicardium (outer layer of the myocardium)
1) What is the pericardial cavity?
2) What is the transverse pericardial sinus?
3) What is the other pericardial sinus?
1) Potential space with thin film of serous fluid
2) Reflection of pericardium
3) Oblique pericardial sinus
What structure of the heart is similar to the pleura of the lungs?
The pericardium
What would fluid in the pericardial cavity cause?
The heart wouldn’t be able to move to fully fill; CO would drop and so would venous return
Why does cardiac tamponade (fluid in pericardium) affect diastole?
Fibrous pericardium doesn’t stretch
What are the 3 layers of the pericardium?
1) Fibrous (gray)
2) Parietal serous
3) Visceral serous (aka epicardium)
What is the epicardium also called?
Visceral pericardium
