Intro Heart/Lungs Anatomy Flashcards
Divisions of the thorax
Superior and inferior thoracic aperture
Superior, anterior, middle, and posterior mediastinum
What is this structure?
Pericardial cavity
Surrounded by visceral and parietal pericardium
What heart condition is shown on this CT?
Cardiac tamponade: heart is surrounded by fluid that is not compressible, making it difficult for the heart to expand and contract to pump blood
Layers of the pericardium?
- Endocardium
- Myocardium
- Visceral serous pericardium
- Space with pericardial fluid
- Parietal serous pericardium
- Fibrous pericardium
How thick are the walls of the ventricles?
LV –> 15-30 mm thick
RV –> 5-10 mm thick
What does this heart demonstrate?
Ventricular hypertrophy
If the heart muscle has to work harder than normal, the muscle hypertrophies into the ventricle, decreasing the SV by taking up space from the blood.
Name the structures visible on this heart
Name the structures shown
Name the structures shown in the RA
The sinus venarum is smooth because it is an embryonic vessel wall
Name the structures shown in the right ventricle
Name the structures of the left atrium and ventricle shown
Name the two valves shown and their structures
What chambers of the heart do they separate?
Chordae tendinae attach to the papillary muscles
When the ventricle contracts, the papillary muscles are pulled tight, keeping the valve tightly shut
Right hand side is inherently weaker because it has three valves, rather than the two on the left - stronger valve on stronger side
Name the valves shown and their structures
What compartments do they separate?
Semi lunar valves have stiffened edges, so when the backflow comes into the parachutes, it expands them, pushing the hard edges together to close the valve tightly.
The gentle backflow in the semilunar valve is what fills the coronary ostia, providing the coronary blood flow.
We can hear the opening and closing of these valves in the heart
What structure is shown here?
What two main functions does it provide for the heart?
The heart has a very important fibrous skeleton, that provides structure for the valves to hang off. Maintains the integrity of the valves despite the pressure in the heart.
Also, the only place where electrical impulse can pass from atria to ventricles is through the trigone of the fibrous skeleton. The rest of it acts as an electrical insulator.
What is demonstrated in the heart pictured?
What physical finding does it produce?
Aortic stenosis, where the edges of the valves develop plaques, become stiff, and no longer close tightly together.
Leads to an audible heart murmur.
List the major arteries of the coronary circulation
What portions of the heart are supplied by each?
Both come off aortic arch just after the valves.
Whichever artery supplies the interventricular branch is the dominant coronary artery; in 2/3 of people it is the right artery.
Components of the right coronary circulation
The marginal branch is the first large branch off the RCA; it goes around to the back of the heart
Components of the right coronary blood supply, posteriorly
Components of the left coronary circulation, anteriorly
Components of the left coronary circulation, posteriorly
Components of coronary venous drainage
Components of the cardiac conduction system
The heart has an intrinsic rhythm of its own, and the base contraction rate comes from the SA node. Changes in heart rate come from the autonomic nervous system, and modify the base rate.
The AV Bundle is the only place in a healthy heart where impulses should pass between atria and ventricles.
The electrical impulse then travels down through the IV septum in the right and left bundles, and then back up through the Purkinje fibers.
As the heart contracts, it starts in the atria. This fills the ventricles completely. As it tracks down, then the ventricle contracts. Both sides happen at the same time.
If there is cross talk between the ventricles and atria, the pump loses it’s order and thus becomes inefficient.
What is the sympathetic and parasympathetic innervation of the heart?
T1 to T4-5 contributes to the CARDIAC PLEXUS, which provide sympathetic innervation –> fight or flight response
Vagus nerve (CN10) provides the parasympathetic innervation, which slows the heart for rest and digest.
Innervation of the heart and diaphragm
C3, 4, 5 keep the diaphragm alive!
