Heart & Vessels Flashcards
Heart Anatomy & Structures
Aortic valve
The valve between the left ventricle (bottom chamber of the heart) and the aorta (big artery carrying blood to the body).
- Semilunar (SL) valve
Heart Location and Structure:
where is the heart located?
The heart is situated in the mediastinum, spanning from the 2nd to the 5th intercostal space.
- It stretches from the right edge of the sternum to the left midclavicular line.
Heart Location and Structure:
Can you describe the shape of the heart?
It’s often likened to an upside-down triangle.
- The base is at the top and
- the apex points downward and to the left.
Heart Location and Structure:
how many chambers does the heart have, & what are they called?
The heart has four chambers:
1. the right atrium (RA)
2. right ventricle (RV)
3. left atrium (LA)
4. and left ventricle (LV).
Heart Location and Structure:
what is the function of the heart valves?
The heart has four valves that prevent the backflow of blood. These valves are the
1. tricuspid (right AV valve): prevents backflow into the R atrium
2. mitral (left AV valve): prevents backflow into the L atrium
3. pulmonic (right SL valve): prevents backflow into the R ventricle
4. and aortic (left SL valve): prevents backflow into the L ventricle
Tricuspid valve:
- when the R ventricle contracts, the tricuspid valve closes to prevent backflow into the R atrium
- Instead, blood is pushed forward into the pulmonary artery
Pulmonary valve:
- after the R ventricle contracts & pumps blood into the pulmonary artery, the pulmonary valve clsoes to prevent backflow into the R ventricle
Mitral (biscuspid) valve:
- when the L ventricle contracts, the mitral valve closes to prevent backflow into the L atrium.
- this ensures that blood is pumped forward into the aorta
Aortic Valve:
- after the L ventricle contracts & sends blood into the aorta, the aortic valve closes to prevent backflow into the L ventricle
Heart Location & Structure
What are the three layers of the heart wall?
- Pericardium: The outer layer, a double-walled sac that encases and safeguards the heart.
- Myocardium: The middle layer, the muscular wall responsible for the heart’s pumping action.
- Endocardium: The inner layer, lining the heart chambers and valves.
Blood flow
Describe the path of blood flow through the heart, distinguishing between pulmonary and systemic circulation.
Pulmonary Circulation:
1. Deoxygenated blood travels from the body into the right atrium (RA), then to the right ventricle (RV).
2. It’s pumped from the RV to the lungs via the pulmonary artery to receive oxygen
Systemic Circulation:
1. Oxygen-rich blood returns from the lungs to the left atrium (LA), then goes to the left ventricle (LV).
2. The LV pumps this oxygenated blood out to the body through the aorta
“VC, RA, RV, PA,
Lungs give air, send it LA,
LV, AO, body all day!”
Blood flow
Explain how the heart valves ensure one-way blood flow.
Heart valves open and close passively in response to pressure changes within the heart chambers, ensuring that blood flows in a single direction
Cardiac Conduction
What does the term “automaticity” refer to in the context of the heart?
Automaticity means the heart has the inherent capacity to contract independently, without external signals, thanks to its electrical conduction system
- means the heart can contract on its own without needing external signals from the brain or nerves.
- This happens because of the heart’s electrical conduction system, which controls the heart’s rhythm.
Cardiac Conduction
What is the role of the SA node in the heart?
The SA node, often called the “pacemaker” of the heart, initiates the electrical impulse that triggers the heartbeat.
Cardiac Conduction
Outline the pathway of electrical impulse conduction in the heart.
- The electrical impulse originates in the SA node.
- It then travels through the atria to the AV node, continuing down the Bundle of His.
- The impulse then spreads through the bundle branches to the ventricles, causing them to contract.
SA Node → “SAy Aye” (It’s the pacemaker, starting the signal)
AV Node → “AVengers” (The AV node pauses, like superheroes planning the next move)
Bundle of His → “Bundle Up” (Like preparing for the next step)
Right and Left Bundle Branches → “Let’s Branch Out” (The signal branches into two paths)
Purkinje Fibers → “Purk the Party!” (Purkinje fibers fire, and the ventricles contract, finishing the job)
What does an electrocardiogram (ECG) record?
An ECG records the electrical activity of the heart.
- The characteristic PQRST waves seen on an ECG represent the different phases of the cardiac cycle.
P → Atria Push
(P wave: Atrial depolarization, atria contract to push blood into ventricles)
QRS → Quick Response
(Ventricular depolarization, ventricles rapidly contract to pump blood out)
T → Then Reset
(Ventricular repolarization, ventricles reset to get ready for the next beat)
Define cardiac output.
Cardiac output is the volume of blood the heart pumps out (ejects) every minute.
* It is calculated by multiplying stroke volume (the amount of blood ejected with each beat) by heart rate (the number of beats per minute)
what is preload
Preload refers to the amount of blood in the ventricles at the end of the diastole phase, which is when the ventricles are relaxed and filling with blood.
- It’s also a measure of the stretching of the ventricular walls.
explain afterload
Afterload is the amount of resistance the left ventricle has to overcome to pump blood out into the aorta.
What are the primary factors influencing cardiac output?
Four key factors influence cardiac output:
1. preload
2. afterload
2. heart rate,
3. and the heart’s ability to contract effectively (contractility).
Pump → Preload (How much blood fills the heart before it pumps)
Push → Afterload (The pressure the heart must push against to pump blood out)
Pace → Heart Rate (The speed or pace at which the heart beats)
Power → Contractility (The strength or power of the heart’s contraction)
What are the main types of blood vessels?
The main types of blood vessels are:
1. Arteries: These vessels carry oxygenated blood away from the heart (with the exception of the pulmonary artery).
- Veins: These vessels carry deoxygenated blood back to the heart (except for the pulmonary veins).
Describe the two main phases of the cardiac cycle.
- Diastole: This is the period of ventricular relaxation when the ventricles are filling with blood.
- Systole: This is the period of ventricular contraction when blood is ejected from the heart.
What creates heart sounds?
The sounds we hear as the heartbeat are primarily created by the closing of the heart valves and the flow of blood through the heart.
Heart Anatomy & Structures
apex of the heart
The tip of the heart, pointing down, located around the 5th space between the ribs on the left side.
Heart Anatomy & Structures
base of the heart
The wider top part of the heart, located at the 3rd space between the ribs, both on the right and left sides.
Heart Anatomy & Structures
Mitral valve
The valve between the left atrium (upper chamber) and left ventricle.
- AV valve
Heart Anatomy & Structures
tricuspid valve
The “web-y” valve between the right atrium and right ventricle.
- AV valves
Heart Anatomy & Structures
pulmonic valve
The valve between the right ventricle and the pulmonary artery (which carries blood to the lungs).
- Semilunar (SL) valve
Heart Anatomy & Structures
precordium
The area of the chest over the heart.
Heart Anatomy & Structures
midclavicular line (MCL)
An imaginary line down from the middle of the collarbone on each side of the chest.
Heart sounds
S1
the “lub” sound that happens when the mitral and tricuspid valves close at the beginning of the systole phase (ventricular contraction).
- the 1st heart sound
Heart sounds
S2
The “dub” sound that occurs due to the closing of the aortic and pulmonic valves, marking the end of systole.
- the 2nd heart sound
Heart sounds
S3
A soft, extra sound heard early in the heart’s filling phase, possibly indicating heart failure.
- 3rd heart sound
Heart sounds
S4
A low-pitched sound heard late in the filling phase, also associated with heart conditions.
- 4th heart sound
Heart sounds
Gallop rhythm
When you hear an extra (3rd or 4th) heart sound, it resembles the sound of a galloping horse.
Heart sounds:
Summation gallop
When both S3 and S4 sounds are present, which can suggest severe heart issues.
Heart sounds
Paradoxical splitting
- During expiration (breathing out), the pulmonary valve closes first and the aortic valve closes later, creating the split.
- This is abnormal and can happen with conditions like left bundle branch block or aortic stenosis, where the left side of the heart takes longer to contract, delaying the closure of the aortic valve.
L bundle branch block:
- In left bundle branch block, the delay in the electrical signal causes the left side of the heart (and the aortic valve) to work more slowly, making the aortic valve close after the pulmonary valve.
Aortic stenosis:
- In aortic stenosis, the narrowed aortic valve causes a delay in closure, so the aortic valve closes later than the pulmonary valve.
Heart sounds
physiologic splitting
- In physiologic splitting, during inspiration (when you breathe in), you hear two distinct sounds within S2 because the aortic valve closes first, followed by the pulmonary valve.
- This splitting is normal and happens because more blood flows into the lungs during inspiration, delaying the closure of the pulmonary valve slightly.
valvular disorders
aortic regurgitation
the leakage of blood going back into the left ventricle from the aorta (instead of going to the rest of body)
Effects:
1. the L ventricle has to handle a larger volume of blood d/t backflow, leading to L ventricular dilation (enlargement of L ventricles)
2. L ventricle weaken & can fail over time = HF
S/S:
* may be asymptomatic in early stages
* as the condition progresses, symptoms can include:
1. SOB
2. fatigue
3. palpitations
4. swelling in legs & ankles
SOB
- as the heart weakens, fluid builds up in the lungs (pulmonary congestion), making it harder to breathe
Fatigue
- u feel tired bc the heart is not pumping blood efficiently, meaning less O2 is getting to ur muscles & tissues
Palpitations
- the extra amt of blood in the L ventricle makes the heart work harder & faster
- this increased workload can = irregular HB (palpitations) that are more noticeable when lying down/at night
Swelling in legs & ankles
- when the L side of the heart weakens, it can lead to fluid buildup thruout the body bc BF slows down, esp in the lower extremitites
what are the causes of aortic regurgitation?
- rheumatic fever
- infective endocarditis
- connective tissue disorders (marfan syndrome)
- aortic dissection
- trauma
valvular disorders
aortic stenosis
calcification narrows the aortic valve, restrictsing blood flow from the L ventricle to the aorta.
Effects:
* the L ventricle has to work harder to pump blood thru the narrowed aortic valve (to the body) = L ventricular hypertrophy (thickening of heart muscle)
* L ventricle eventually weakens = HF
S/S:
1. chest pain
2. SOB
3. fatigue
4. dizziness
5. fainting
Chest pain (angina):
- the narrowed aortic vave & the reduced BF to the coronary arteries (which supply the heart) deprives the heart of O2 = chest pain esp during exertion
SOB:
- as the L ventricle becomes thicker from working harder to pump thru the narrows valve, it becomes weaker and causes blood to back up into the lungs & making it diff to breathe
Fatigue:
- less O2 rich blood reaches the muscle & organs d/t narrowed aortic valves
Dizziness:
- the brain not getting enough o2 d/t restricted BF out of the heart
Fainting (Syncope):
- drop in BF to the brain = fainting d/t the heart not being able to pump enough blood to maintain enough BP
what are the causes of aortic stenosis
- congenital (present at birth)
- acquired later in life d/t:
* rheumatic fever
* calcium buildup on the valve
* wear & tear with age
valvular disorders
mitral regurgitation
Mitral regurgitation involves leakage of blood back into the left atrium.
- It can cause fatigue, shortness of breath, and heart failure.
valvular disorders
mitral stenosis
The mitral valve becomes stiff or narrowed, blocking blood flow into the left ventricle during relaxation.
* Common symptoms include fatigue, shortness of breath, and atrial fibrillation.
valvular disorder
pulmonic regurgitation
The pulmonic valve doesn’t close properly, allowing blood to flow back into the right ventricle.
valvular disorders
pulmonic stenosis
Pulmonic stenosis involves calcification restricting blood flow through the pulmonic valve, making it harder for blood to flow to the lungs.
What happens in tricuspid regurgitation?
Tricuspid regurgitation involves leakage of blood back into the right atrium.
What is a patent ductus arteriosus (PDA), and what type of murmur does it produce?
A PDA is a continuous “machinery murmur” heard in both systole and diastole.
- It often resolves spontaneously in newborns.
What causes a venous hum, and in whom is it commonly found?
A venous hum is caused by turbulent blood flow in the jugular veins.
- It is common in healthy children.
cardiac physiology
diastole
The phase when the heart relaxes and fills with blood.
cardiac physiology
systole
the phase when the heart contracts and pumps blood out.
cardiac physiology
apical impulse
The strongest heartbeat felt near the 5th space between the ribs, usually where you listen for the heart’s activity.
cardiac physiology
inching
Moving the stethoscope a little at a time across the chest to listen carefully to different heart sounds.
cardiac physiology
palpitation
The feeling of a rapid or irregular heartbeat that you can feel in your chest.
cardiac physiology
thrill
A vibration you can feel on the chest, which is caused by a strong heart murmur.
heart conditions
angina pectoris
Chest pain caused by the heart not getting enough oxygen.