C2: Cardiovascular: Physiology & Assessment Flashcards
Where is the base of the heart?
- Superior, posterior, right
2. 2nd ICS
Where is the apex of the heart?
- Inferior, anterior, left
2. 5th ICS, MCL
List the layers and sub layers of the cardiac wall.
Pericardium
Serous
-parietal
(Pericardial space)
-visceral aka epicardium
Epicardium
Fatty CT
Myocardium
Endocardium
Fxn of pericardium?
Keep heart stationary
Layers of the pericardium?
- Fibrous: protects against infection and neoplasm
2. Serous: parietal, (pericardial space),visceral aka epicardium
Normal amt of fluid in pericardial space?
10-30cc
Constituents of myocardium.
- Specialized conduction fibers
2. Interlacing cardiac muscle fibers
Constituents of endocardium.
- CT
- Elastic fibers
- Endothelial cells
Fxn of endothelial cells.
Form smooth surface for blood contact .:. Deters clot formation
Lines chambers and valves
Type of tissue and Location of cardiac skeleton?
CT at base of the heart and interventricular septum
Describe the atria
Thin-walled, LOW pressure chambers
P in R atrium?
2-6mm Hg
P in L atrium?
8-12 mm Hg
What % of blood fills by passive ventricular filling?
70-75%
What % of blood fills by active ventricular filling and what is the mechanism?
25-30%
Atrial contraction at the end of ventricular diastole
4 inflow tracts to R atrium?
- SVC
- IVC
- Coronary sinus
- Thebesian veins
Outflow tract of R atrium?
Tricuspid
4 inflow tracts of L atrium?
4 OXYGENATED pulmonary veins
Outflow tract of L atrium?
Mitral
Which chambers contain trabeculae?
Ventricles
Describe the thickness of the RV and LV
RV: thin walled
LV: thick walled
RV Pressure
Low 25/5
Outflow tract of RV?
Pulmonary artery (DEOXYGENATED)
Describe LV position
Posterior
Pressure in LV?
LV 120/5
Outflow tract of LV
Aorta
Purpose of cardiac valves
Maintain unidirectional flow
Define stenosis
Narrowing of the valvular orifice preventing normal antegrade flow
3 definitions for the inadequate closure of the valvular orifice allowing retrograde flow
- Regurgitant
- Incompetent
- Insufficient
Position of AV valves during diastole? Is this active or passive?
Open, passive
Position of AV valves during systole? Mechanism?
Closed
Active process by contraction of papillary muscles
Which heart sound accounts for the closure of the AV valves?
S1
Components: M1 and T1
Describe the location of the semi lunar valves
Between the ventricles and the great vessels
What are the components of the semi lunar valves
An annulus and three cusps
How do the semi lunar valves operate?
Pressure gradients
Which heart sound are the semi lunar valves are responsible for?
S2
Components A2 and P2
Where are the coronary arteries located?
The first branch off the aorta, immediately after the aortic valve
What percentage of cardiac output does the myocardium receive
5% also, it extracts 65 to 80% of oxygen in the blood even at a basal rate
How is bloodflow in the coronary artery is regulated
Almost entirely by local auto regulation based on the myocardium’s metabolic demands
When is the left ventricle perfused
Primarily during diastole due to compression of the musculature (and therefore intramuscular vessels) during systole
When is the right ventricle perfused during the cardiac cycle
greater in diastole but throughout the cardiac cycle
Define aortic root pressure
The pressure in the aorta immediately outside the aortic valve. This is a significant part of coronary artery filling pressure
What is the equation for coronary artery perfusion pressure (CAPP)?
CAPP= DBP - PAOP
*PAOP aka PA wedge pressure or pulmonary capillary pressure
List the four determinants of myocardial oxygen demand
- heart rate
- Preload
- After load
- Contractility
What are the four determinants of oxygen supply
- Patent arteries
- Diastolic pressure
- Diastolic time
- Oxygen extraction
What parameters affect oxygen extraction
- hemoglobin
2. Arterial oxygen saturation (sao2)
What are the two main coronary arteries?
The left main coronary artery and the right coronary artery
The left main coronary artery bifurcates into which two vessels
- LAD left anterior descending
2. LCA Left circumflex artery
Which areas of the heart does the LAD supply
- Anterior LV
- Anterior 2/3 of IVS
- Apex of LV
- Bundle of his and bundle branches
Which areas of the heart does the LCA supply
- LA
- SA node 45% of hearts
- AV node 10% of hearts
- Marginal (obtuse marginal) branch supplies Lateral LV and posterior LV
Which areas of the heart do the RCA supply
- Right atrium
- SA node (55% of hearts)
- L posterior hemibundle (dual blood supply from RCA and LAD)
- Marginal branch
Which areas do the marginal branch of the RCA supply
- Lateral RV
2. Inferior RV
What percentage of hearts are dominated by the RCA
80%
In RCA dominant hearts, a branch of RCA referred to as the posterior descending artery PDA supplies what parts of the heart
- Anterior RV
- Inferior wall of LV
- Posterior LV
- Posterior 1/3 of septum
What is collateral circulation
Dear arterial vessels that connects a.k.a. anastomose with each other
What factors foster the development of collateral circulation
Anemia, hypoxia, and arteriosclerosis
Where do most coronary veins empty
Right atrium
The Thebesian veins drain some of the venous blood from the myocardium directly into where
Right atrium, right ventricle, and left ventricle rather then the coronary sinus
What is the physiological effect of venous blood emptying directly into the left ventricle
It creates a normal physiologic shunt because it slightly decreases the oxygen saturation
Describe the pathway of cardiac lymphatic drainage
Main cardiac channel>pre tracheal node>lymphatic duct
What facilitates cardiac lymphatic drainage
Contraction
