Intro to CV Flashcards
How much blood resides in the venous system?
2/3
How much blood resides in the heart?
7%
How much blood resides in the pulmonary circulation?
10%
How much blood resides in the arteries?
13%
Define pericardium
avascular, fibrous sac surround heart
Function of the pericardium?
confines heart to position in mediastinum with sufficient freedom of movement while preventing over-stretching
Describe composition of the parietal pericardium.
aka fibrous pericardium
– touch, inelastic, fibrous CT of collagen + elastin
Where does the fibrous pericardium attach?
sternum, diaphragm, anterior mediastinum, great vessels
Describe composition of visceral pericardium?
single layer of mesothelial cells attached to the epicardium
Function of the visceral pericardium?
Vagal reflexes (it is innervated) secretion of prostanoids for cardiac reflexes & tone
Function of the serous fluid in the pericardial cavity? How much fluid?
reduce friction, 15-50mL
What is pericarditis?
inflammation of the pericardium with an increase in pericardial fluid, caused by infection, surgery, & trauma
What is cardiac tamponade?
the effusion of pericardial fluid such that the heart cannot stretch…decreased filling –> shock?
What are the 3 layers of the heart?
1) epicardium
2) myocardium
3) endocardium
composition of the epicardium
thin, transparent, delicate CT
composition of the myocardium
thickest layer consisting of cardiac myocytes
composition of the endocardium
endothelial cells continuous with lining of the great vessels
What is the bicuspid valve?
the mitral valve – left AV
What is the function of chordae tendinae?
connect AV valves to papillary muscles to help withstand high pressure during contraction
What valves are supported?
AV only
What are the semilunar valves?
Aortic & pulmonary
How much does the heart pump per minute?
5L (30*weight!)
