Slide Set 4 Flashcards
The mediastinum is located
Between the lungs
The mediastinum contains
the heart, trachea, esophagus, and great vessels
The heart is located in
the middle inferior mediastinum
Which nerves drive the diaphragm
The phrenic nerves
The right vagus nerve innervates
the SA node
The left vagus nerve innervates
the AV node
SA node would fire at ____ with no PNS stimulation
110
How many serous layers of the pericardium? What are their names
2; inner or visceral serous pericardium and parietal serous pericardium
What is the outermost layer of the pericardium
the fibrous pericardium
Where does the heart sit
In the middle of the diaphragm on the central tendon
What vessel causes patent ductus arteriosus and what is it’s purpose during fetal development
Ligamentum arteriosum; it helps circulate blood around the body without using the lungs for gas exchange
Which valve only has two cusps
Mitral
What connects directly to the AV valves
The chordae tendineae
The valves are anchored to the heart wall by
the chordae tendineae and papillary muscle
NCC is
non coronary cusp; the posterior cusp of the aorta
Name the cusps of the mitral valve
Anterior and posterior cusps; attached to the posterior cusp is a the commissural cusp
Name the cusps of the tricuspid valve
Anterior, posterior, septal cusps
Name the cusps of the pulmonic valve
Right, left, and anterior cusps
Name the cusps of the aortic valve
Right, left, and posterior (NCC) cusps
What drives coronary perfusion
Aortic pressure
What opposes coronary perfusion
Wall pressures
Calcified or poor fitting aortic valves cause
decreased coronary perfusion
What is the purpose of the cardiac cartilaginous ring
Electric insulation between the atria and ventricles
The cardiac cartilage has a tendency to rattle during
Filling/diastole
Pedi hearts are more resistant to? How do they compensate?
Increases in volume; compensate through increasing HR
Why do we have more mitral valve problems than tricuspid valve issues?
Higher intraventricular pressures on left side
The LCA splits into
The left anterior descending artery and circumflex artery
The RCA feeds into the
posterior descending artery in 85% of people
15% of people have a posterior descending artery that comes off the
LCA
Codominance of the coronary arteries occurs when
There is an anastomosis or connection between the RCA and LCA (circumflex)
Where do you listen to the aortic valve
2nd ICS on the right side of the sternum
Where do you listen to the pulmonic valve
2nd ICS on left side of the sternum
Where do you listen to the tricuspid valve
5th ICS on the left side of the sternum
Where do you listen to the mitral valve
5th ICS left side of the sternum, midclavicular
Longest heart sound? How long is it?
1st heart sound; 0.14s
The first heart sound is
the closure of AV valves; low pitched
The second heart sound is
the closure of the aortic valve; high pitched
What is physiologic splitting of heart sounds
Occurs when the aortic valve shuts first and then the pulmonic valve; may be loudest during inspiration - inspiration causes a drop in afterload and pulmonary arterial pressures, causing the pulmonic valve to close slower
Frequency is measure in ___? How can we calculate it?
Hz or kHz; Freq = number of oscillations over 1s
What is the normal range of hearing in Hz?
20-20000
The third heart sound is
The rattling of cartilage during filling (end of rapid filling typically)
If we could hear it, the fourth heart sound may be
atrial kick due to the pushing of extra blood into the ventricle
Aortic stenosis would present as what type of murmur? Why?
Systolic; Ejection of blood against a noncompliant valve in the aorta
Mitral stenosis would present as what type of murmur? Why?
Diastolic; heard at the end of diastole d/t poor filling of the left ventricle
Mitral regurgitation would present as what type of murmur? Why?
Systolic; during ejection, blood is moving backwards d/t high ventricular pressures
Aortic regurgitation would present as what type of murmur? Why?
Diastolic; during filling, aortic pressure is higher than ventricular filling and leads to increased filling of LV during diastole
What is the loudest murmur?
Aortic stenosis
Patent ductus arteriosus has a murmur that lasts the whole cardiac cycle. When is it the loudest? Why?
During systole d/t shunting of blood from aorta to pulmonary artery
A high delta P of aortic and ventricular pressures indicates
Higher amount of coronary artery perfusion
When does retrograde perfusion of the coronary arteries occur? Why?
During the beginning of systole; intraventricular pressures exceed aortic pressure
In aortic stenosis, the body may compensate for decreased SV by raising heart rate. What ways does this hurt the coronary arteries?
Decreased time spend in diastole when we already have increased wall pressures
