Lecture 1-30 (Anatomy) Flashcards
Cardiac
The R vagus nerve handles the ______ node, and the L vagus nerve handles the_______ node
SA
AV
What happens to HR if you lose vagal stimulation?
Increases
Which is more active in the heart, vagal or sympathetic stimulation?
vagal
What is your heart rate without sympathetic stimulation?
60
Where is sympathetic stimulation more prominent?
Ventricles
Where is vagus stimulation more prominent?
SA/AV node
What are the three pericardial layers?
- Fibrous pericardium.
- Serous pericardium, parietal layer.
- Serous pericardium, visceral layer.
Describe the fibrous pericardium
-most outer layer
-rigid (not a lot of give)
-glued to the serous pericardium, parietal layer
Describe the serous pericardium, visceral layer
-Innermost layer
-transparent and very thin
-very stretchy (a lot of give)
-helps the heart move around w/o a lot of friction w/ filling and ejection
Which pair cardio layer covers the outside of the heart?
Serous pericardium, visceral layer
Describe the serous pericardium, parietal layer
-a part of the outer layer, but glued to the inside of the fibrous pericardium (between the fibrous pericardium and the serous pericardium, visceral layer)
-slippery
-also helps the heart move around
-doesn’t have a lot of give
T/F: The Serous pericardium, parietal layer has a lot of stretch and give
F
Glued to the fibrous pericardium, doesn’t have a lot of give, but it’s slippery
Electrical signal through cardiac cell is done via _____
Gap junctions
What are the two ions for AP cell conduction in cardiac cell? Most important?
Na (most important)
Ca (move slower because it’s bigger)
Describe the 2 layers in the ventricle
- Endocardial fibers.
- Epicardial fibers.
They are oriented at perpendicular angles
When the heart squeezes/ contracts they move in different directions. It’s similar to the motion of ringing out a towel. It is an efficient way to plant blood into a high-pressure system.
AV valves are between what?
Atria & ventricle
What is another name for cusps?
Leaflets
The actual parts of the valves, not the valves themselves, are called?
Cusps
Where are cusps attached?
The inside of the ventricle to Chordae tendineae
What are papillary muscles continuous with?
Ventricle muscle cells
What is Chordae tendineae attached to?
Cusps –> Chordae tendineae –> papillary muscles
The Chordae tendineae is what type of tissue?
connective tissue
When the ventricle contracts, the ________ contracts
papillary muscles
What are the supporting structures for the AV valves? What do they do?
Papillary muscles
When the pressure is high in the ventricle, they prevent the AV valves from getting blown back into the atria
What problems should we expect to see with an MI? why?
MI = vent wall infarct –> papillary muscle in continuous w/ vent muscle cells
Initially you’ll see a problem with pumping but bc the papillary muscle is damaged as well, you’re going to see valve problems bc there’s damage to the supporting structure
When are the AV valves open?
Filling (diastole)
When do the AV valves close?
When the heart starts to contract
What is the normal EF in L ventricle?
70 ml / 120 ml = 58.33%
(ejected) / (starting volume)
What are the names of the AV valves? Where are they located?
Tricuspid valve: R heart
Bicuspid valve: L heart
How many leaflets does the bicuspid valve have? What are their names?
2
Anterior cusp
Posterior cusp
How many leaflets does the tricuspid valve have? What are their names?
3
Anterior cusp
Posterior cusp
Septal cusp
Where is the septal cusp in the tricuspid valve located?
-medial (more to the L)
-fastened into the wall of the intraventricular septum
How many semilunar valves do we have? what are their names and locations?
2
Pulmonary valve: L heart
Aortic valve: R heart
How many leaflets does a pulmonary valve have? What are their names?
3
Anterior cusp
Right cusp
Left cusp
How many leaflets does the aortic valve have? What are their names?
3
Posterior cusp
Right cusp
Left cusp
What color is the pulmonary valve?
P = purple
What color is the aortic valve?
The R in aortic = red
From a superior view, the pulmonary valve sits ________ to the aortic valve
Anterior
What are things that can prevent the valves from closing properly? What is the result from this?
Infection, which causes the immune system to attack the valve
Increase cholesterol which causes calcification
These things can cause leaky valves
What happens if the semilunar valves get leaky?
You get backflow into the ventricles –> ventricles stretch out –> further exacerbation of valve problem
Where are the openings to the coronary arteries located?
The very early part of the aorta
L coronary art: L cusp of the aortic valve area
R coronary art: R cusp of the aortic valve area
The ________ assist with coronary artery perfusion during ___________ because it acts as a___________ that helps direct blood flow
Aortic valve
Diastole
Bowl
What are the coronary arteries most perfused?
Diastole
After L ventricle ejection, aorta pressure is __________. What does this help with?
High
Helps to direct blood into the coronary arteries
The aorta gets ________ during systole. Why?
Bigger
To accommodate more blood
When does retrograde blood flow happen in the aorta? What does this help with?
During diastole
Helps with coronary artery perfusion
What happens if you get aortic valve damage?
Blood will not only start flowing back into the ventricle, but you’ll also have decreased coronary artery perfusion due to the cusp not being able to act as bowls anymore
T/F: you don’t lose aortic valve functionality with age if you’re healthy
F
With age, you lose some degree of functionality of the aortic valve
describe the pathology for aortic stenosis
Valve narrowed & stiff –> harder for blood to pass through –> heart works harder against increase resistance –> L vent pressure increased —> metabolic demands increased for heart
While also decrease coronary artery blood perfusion/flow –> which worsen the conditions because the metabolic demands for the heart have increased
What structure acts as insulation and separates the atrial and ventricle electrical activity? Why? Where is this located?
Cardiac cartilaginous ring
Cartlidge doesn’t conduct electricity well
This structure is formed early in development. It expands as we grow and the heart is built on top of it.
What is the only place in a healthy heart that should allow for electrical communication between the atria and ventricles?
The bundle of His
T/F: the bundle of His is the only place that allows for the AV note to fire in AP into the ventricles
F
Some genetic abnormalities have extra electrical pathways that are treated with ablations if problematic
The mitral valve has a 3rd small, unofficial cusp. What is it called? What other cusps is it a part of?
Commissural cusp
Posterior cusps
What are the two main arteries that branch off of the L coronary artery? Where are they located?
Left anterior descending artery (LAD): large branch that runs in the front/middle of heart
Circumflex artery: goes around the side and then back of heart
What artery branches off of the R coronary artery? Where is it located? What does it do?
Posterior descending artery (PDA)
Posterior/base of heart
Major vessel supplying blood to the posterior of the heart
What is special about the posterior descending artery?
It can branch off either the R coronary artery or the circumflex artery which branches off the L coronary artery.
Where is the great cardiac vein? What does it feed into?
Posterior/inferior part of heart
Coronary sinus
What is the tail end of the great cardiac vein called? What is it continuous with? What is its relevance?
Coronary sinus
R atrium
It is where deoxygenated coronary blood is sent through the lungs on the next heartbeat (coronary sinus –> R artia –> R vent –> pulm circuit)
Where is the deoxygenated coronary blood sent from through the lungs?
Coronary sinus
What is a normal coronary blood flow value to satisfy the metabolic demands of the heart? What can increase or decrease this number?
70ml/min/100 grams or
225ml/min
Increasing or decreasing the metabolic demands of the heart
The smaller blood vessels branching off from the coronary artery are embedded within the heart muscle, therefore their vascular resistance depends on what?
Surrounding tissues, pressure = pressure of the atria/ventricle that it’s around
The coronary arteries and superficial veins that are visible are called __________, and veins embedded into the heart muscle law are called ________
Epicardial blood vessels
Endocardial blood vessels (deep) or
Sub endocardial blood vessels (deepest)
When do you see a drop in coronary perfusion? What is this due to?
Systole
High pressures in certain regions of the heart
What areas of the heart experience very high-pressure during systole, therefore dropping coronary perfusion in that area?
L ventricle
Intraventricular septum
What areas have less effect on coronary blood flow during systole? Why?
The right ventricle and the atria
Even during systole the R vent has a low pressure. The atrias have a low pressure overall.
________ is critical for perfusion to the L ventricle and interventricular septum due to ________ pressures
Diastole
high
When is right coronary flow highest? Left coronary flow?
Right: during systole
Left: during diastole
Right coronary perfusion is _________ through the cardiac cycle
Continuous
Generally, the left coronary artery provides blood to the ______ pressure side of the heart, and the right coronary artery provides blood to the ________ pressure side of the heart.
high
low
there is crossover
T/F: left coronary blood flow can go negative. Why?
T
This is due to retrograde blood flow in the veins embredded in the heart walls during early systole
What is ΔP for coronary blood flow?
Aortic pressure - wall pressure
Anytime the aortic pressure is _________ than wall pressure, we have coronary blood flow.
higher
** ΔP will be positive**
what happens when wall pressure is higher than aortic pressure?
We can have reverse coronary blood flow
** ΔP will be negative**
When we ________ aortic pressure and/or _______ wall pressure, we decrease coronary blood flow
decrease
increase
Increase HR –> _________ –> __________ heart metabolic demand –> ____ filling time –> ________ coronary perfusion time
decreased
increased
decreased
If fairly young/healthy can tolerate slight tachy for awhile
How is the cardiac cycle affected when HR is increased? How does this affect coronary perfusion time?
Phase 2 of diastole is removed because a lot of filling doesn’t happen here
Decrease his coronary perfusion time
T/F: if patients have bad coronary arteries it’s OK to take away phase 2 of diastole
F
Increasing heart rate and taking away phase 2 of diastole is going to decrease coronary perfusion time. These type of patients are depending on phase 2 for coronary blood flow.
What is aortic stenosis?
Narrowing of the aortic valve –> causing obstruction flow from the left ventricle –> causing the pressure in the L vent to increase
Aortic stenosis ________ left ventricle pressure
Increases
Describe the pathology of mitral valve stenosis
Filling problem
Atria pressure increases to be able to fill the vent
CO decrease –> BP decreases –> kidney expands blood volume
T/F: atria pressure decreases after compensation in mitral valve stenosis
F
It stays elevated
Aortic stenosis ________ PP
Narrows
Describe the pathology of aortic regurgitation
Leaky aortic valve –> when valve closes blood leaks backwards into L vent –> increases L vent volume -> stretches vent –> worsens valve –> L vent hypertropy
Aortic regurgitation ________ diastolic pressure
Decreases
Aortic pressure _________ during diastole in aortic regurgitation
Decreases
What happens to the PP in aortic regurgitation? Why?
Widens
Because the aortic pressure drops during diastole –> ** which causes the diastolic pressure to be low**
The atria fills during ______
systole
Describe the pathology of mitral valve insufficiency
During systole –> mitral valve supposed to be closed but leaky –> blood being ejected into aorta AND back into atria through leaky valve –> Pressure increases in atria bc being filled from 2 places
Pressure in the atria ______ during mitral insufficiency. Why?
Increases
During systole, the atria is being filled from the pulmonary veins and the left ventricle at the same time
Spinal anesthesia decreases _______. How do we fix this?
-Psf (systemic filling) <– mainly
-Sympathetic influence at the heart
volume
tighten veins
Describe the A wave on the CVP waveform
Increase in atrial/CVP pressure dt atrial contraction
Appears at the end of diastole
Since there is no valve at the rear of the atria during a contraction, some blood is pushed forward and some is pushed back. This causes a spike in CVP wave form.
Describe the C wave in CVP waveform
dt AV valves bulging back towards atria when the ventricles contract
Appears in the beginning of systole
Describe the V wave in the CVP waveform
Result of the atria filling wall AV valves closed
Appears in late systole
T/F: blood is returning from circulation continuously in the atria
T
Blood is flowing continuously in both atria into pressure builds up high enough to open the AV valve
Describe the X descent on the CVP waveform
Product of decrease in atrial pressure dt atria being really empty
After C wave
Mid systole
Describe the Y descent on the CVP waveform
AV valve opens in atrium pressure decreases dt rapid filling in vent
Appears after the V wave
Early diastole
What is PVR values?
40 - 180 cgs
What are the units for SVR/PVR?
Dynes ·sec/cm5
SVR =
((MAP - RAP) / CO) x 80
units: cgs
** use CVP if you don’t have R atrial pressure**
PVR =
((MPAP - PAWP) / CO) X 80
units: cgs
What is PAWP?
Pulmonary artery wedge pressure
Measured by Swan-Ganz in the pulmonary artery
Balloon is inflated to create a column of blood that reflects L atria pressure
Slightly higher
What is an acceptable value for PAWP in a healthy person?
8 mmHg
PRU =
((MAP - RAP) / CO)
CO is rounded to 100 ml/sec
What is a normal peripheral resistant units value for the systemic circulation?
1 PRU
How do you convert PRU to cgs in the systemic circulation?
Multiply by 1333
Sicker patients are mostly likely on the _______ end of the SVR/PVR range
lower
Making intrapleural pressure more negative causes cardiac output to _________, making it more positive causes it to ________ dt ______
Increase
Decrease
Decreased venous return causing decrease CO
How does inspiration affect CVP/PAP?
Decreases
During inspiration pressure and chest decreases dt contracting diaphragm to fill lungs.
Pressure in veins in chest decrease dt being pulled on from surrounding negative pressure in the chest
This pulls more blood into the thorax instead of the heart
T/F: blood can be pulled out of the right atria during inspiration
T
What are the effects of the right heart and the left heart during inspiration?
RH: CO decreases
-preload decreases
-afterload decreases
LH: CO decreases alot
-Preload decreases alot
-afterload stays the same
During inspiration, what happens to the pressure in the pulmonary artery and vein?
Decreases
Why does afterload of the left heart stay the same during in inspiration?
Because blood is being pumped into the aorta, which has a low compliance because it is rigid and stiff, so it’s not really affected by these negative pressures in the thorax from inspiration
