1.1.3 Heart Structures Flashcards
What causes the “dub” sound in the cardiac cycle?
Beginning of diastole, the closing of the aortic and pulmonary valves
Ischemic cardiac pain due to inadequate blood flow is carried back to the CNS by afferent nerves that enter the spinal cord where?
C4 to T5
Which layer of the serous pericardium is “on the wall”?
The parietal layer
What is a coronary artery bypass surgery?
An artery is attached to the distal end of the coronary artery, thus bypassing the blockage. This usually requires multiple grafts
What is the purpose of the tricuspid valve?
Allows blood to flow from RA to RV during diastole
What innervates the pericardium?
The phrenic nerve (C3, 4, and 5) - both motor (stimulates contraction of the diaphragm) and carries afferents from the pericardium and diaphragm
In this anterior view of the heart what does each number represent? Numbers 2 and 3 combined make up what?
1 - Fibrous pericardium
2 - Parietal Layer
3 - Visceral Layer
The Parietal and Visceral Layer make up the serous pericardium
In this picture, what do the numbers 1 and 2 represent?
1 - Transverse pericardial sinus
2 - Oblique pericardial sinus
What are the main components of the venous system in the heart?
Return to the venous circulatory system occurs at the RA through either the Coronary sinus or the anterior cardiac veins. Blood reenters the heart at the RA.
What do each of the numbers in this picture of the right atrium mark?
- Sinus Venarum
- Pectinate muscles (righ atrial appendage)
- Crista Terminalis - Superior end marks SA node
- Fossa Ovalis
- Opening of coronary sinus
- Inferior vena cava and valve
- Superior vena cava
- Right AV orifice
SA node lies where?
In the right atrial wall
When does the mitral valve close?
The beginning of systole
What would be the classical presentation of pericarditis in regards to the quality and location of the associated pain?
The pain tends to be substernal and can sometimes go to the back and shoulders. It often becomes worse upon lying down (opposite of heart attack) or when inhaling deeply (pericardial sac is attached to diaphragm)
What would the classic presentation of a cardiac tamponade be in a clinic?
Jugular venous distention (due to elevated venous pressure) , distant heart sounds, and hypotension with dyspnea
What are the two arteries and one vein that tend to be harvested for bypass surgery?
Internal thoracic and radial artery
The great saphenous vein
What are some causes of left ventricular hypertrophy and chamber dilation?
Volume overloading, as a consequence of aortic or mitral valve regurgitation
What is a cardiac tamponade?
It is the compression of the heart due to rapid accumulation of fluid in the pericardial sac, preventing the chambers from fully expanding, and limiting the stroke volume.
What is the pericardial fluid?
It is thought to be produced by the visceral pericardium and thought to be an ultrafiltrate of plasma
What is the pericardial cavity?
It is a space that is normally filled with 15-50ml of lubricating fluid that allows the heart to move freely as it beats in a low friction environment.
What can be a result of a mitral valve prolapse?
It may develop into a mitral valve regurgitation which can lead to pain, arrhythmias and shortness of breathe
What is a mitral valve prolapse?
The mitral valve will evert into the left atrium when the LV contracts
When do the pulmonary valves close?
These are part of S2 beginnign of diastole
What is the base of the heart?
Posterior aspect of the heart formed largely by left atrium along with a narrow portion of the right atrium
What is the obtuse margin (left margin)?
The rounded left side of the heart formed be the left ventricle and to a small extent the left auricle
Where are the most common locations for heart attack pain in males?
Left arm and chest
Shoulder and neck
Sometimes in center of back
What is the role of the SA node?
It initiates heartbeats
Why would a mitral valve prolapse be more common than a tricuspid valve prolapse?
It is more common becasue the left ventricle contracts at higher pressure to pump blood though out the body