Cardiac - General Knowledge

Who was considered the Father of circulation by showing how the system works with his anatomical studies in animals?

William Harvey (1578-1657)

Who believed that the liver made blood from ingested food and that the starting point of the circulatory system begins in the guts?

Galen (130-200 AD)

What two parts make up the circulatory system?

- Pulmonary (central) circulation = Heart and Lungs- Systemic (peripheral) circulation = Rest of body outside the heart and lungs

What is the circulation that supply blood to the heart?

Coronary (central) circulation

What artery carries deoxygenated blood?What vein carries oxygenated blood?

- Pulmonary artery- Pulmonary veins

At any given time, how much blood (%) would be found in:1) Left ventricle?2) Arteries (including Aorta)?3) Capillaries?4) Veins?5) Right ventricle + Pulmonary arteries?

1) 4%2) 16% (~1/6 of the blood)3) 4%4) 64% (~2/3 of the blood)5) 4%<There's 7x amount of blood in the systemic circulation than the pulmonary circulation & the Venous system carries about 2/3 of the blood supply>

What is the driving force for the flow of blood in the systemic circulation?

The pressure difference between arterial and venous sides of circulation; ~84 mm Hg mean arterial difference. Same with pulmonary circulation, but at a much lesser magnitude.

What's the average amount of times the heart beats; be more specific than 60-100 bpm?

70 times a min for ~90 years

How much blood does the heart pump in one day?

1800 gallons

How much work can a heart do over a lifetime?

Enough work to lift 30 tons to over 30,000 ft in the air.

What describes:- A loose-fitting enclosed sac located between the lungs in the mediastinal space of the intrathoracic cavity- Contains two layers:1) Visceral = Epicardium2) Parietal- Between the two layers contains a cavity with 30-50 mL of serious fluid to minimize friction between the two layers?

Pericardium

What describes:- The visceral layer of the pericardium- Covers the entire heart and great vessels?

Epicardium

What describes:- The space between the two layers of the Pericardium- Contains 30-50 mL of serious fluid (chance for Third spacing = misplaced fluids)- Minimize friction between the two layers?

Pericardial cavity

Which part of the heart is the most:- Superior?- Inferior?

- Base- Apex

Which part of the heart has the thickest walls?

Left ventricle (for the amount of work needed to pump to the entire body)

What describes:- The muscle of the heart- Striated with fibers separated with INTERCALATED DISKS (Unique to heart muscles)- Cells dividing, recombining, and dividing again - Composed of sarcomeres that contain actin and myosin filaments- Smaller than skeletal muscles and has longer contraction- Contains many large mitochondria, reflecting their energy needs?

Myocardium

What minerals is needed for Contraction (Think Action potential)?

- Calcium- Potassium- Sodium

What is the purpose of the Intercalated disks that is unique to heart muscles?

Contains gap junctions that serve as low-resistance pathways for passage of ions and electrical impulses from one cardiac cell to another.MEANING, that the myocardium acts as a single unit = Syncytium.

What describes:- A thin, 3-layered membrane- Lines the heart and covers the valves1) Innermost layer = Lines the heart chambers, smooth endothelial cells2) Middle layer = Dense connective tissue with elastic fiber3) Outermost layer = Irregularly arranged connective tissue cells, contains blood vessels and branches of the conduction system?

Endocardium

What describes:- A bacteria that targets the Endocardium, leading to valve damage- Look for throat infection or rheumatic fever in children?

Streptococcus

What describes:- A bacteria infection that targets the Endocardium- More common in older pt and people who use unclean needles?

Staphylococcus endocarditis

What heart valves are there?

- Semilunar valves = Aortic & Pulmonic- AV valves = Tricuspid & Mitral (bicuspid)

What muscle supports the AV valves from the walls of the ventricles?What attaches them to the valves and helps prevent back flow of blood to the atrium?

- Papillary muscles- Chordae tendineae

What describes:- Valves narrowing leading to valves not opening properly?- Blood flowing backwards into the heart?

- Stenosis- Regurgitation

What sound would you hear if over a heart valve with Stenosis (narrowing of valve)?

- Murmurs for DISEASED valves produced by turbulence and rapid blood flow- Clicks if just the opening is impaired

What are you Auscultating if you are listening at:- 2ICS @ RSB?

Aortic space

What are you Auscultating if you are listening at:- 2-3ICS @ LSB

Pulmonic valve

What are you Auscultating if you are listening at:- 4-5ICS @ LSB?

Tricuspid valve

What are you Auscultating if you are listening at:- 5ICS @ MCL?

Mitral valve

What are the parts of the Cardiac cycle?

- Systole = Period when ventricles contract/depolarize (Inc Na in) = Ejection of the blood- Diastole = Period when ventricles relax/repolarization (Inc K out) and filling of blood

What part of the electrocardiogram represent:- Atrial depolarization?

P wave

What part of the electrocardiogram represent:- Ventricle depolarization- Atrial repolarization?

QRS wave

What part of the electrocardiogram represent:- Ventricle repolarization- Diastole, heart is filling?

T wave

What heart sound:- Isovolumetric contraction period- Initiated at the onset of systole- Reflects the closure of AV valves?

S1

What heart sound:- End of systole- Abrupt closure of Semilunar valves?

S2

What describes:- A period of Ventricular systole- Initiated at the onset of systole- Reflects the closure of AV valves- Can hear S1?

Isovolumetric contraction period

What describes:- A period of Ventricular systole- The 0.02-0.03 sec between S1 and S2 where the vol of blood remains the same, then the ventricles contract → Pressure inside ventricle > Pressure in arteries- This leads to the opening of Aortic and Pulmonic valves?

Ejection period

After the ejection period which forces the Semilunar valves to open, how does the valves close?

At the end of systole, the ventricles relax → ↓Intraventricular pressure → Blood in large arteries flow BACK into ventricles → Semilunar valves shut = S2.

What describes:- A period of Ventricular diastole- Period when ventricles relax for 0.03-0.06 sec- Ventricular volume does not change = No filling- ↓Ventricular pressure until it's less than Atrial pressure → Rapid filling period begins with the opening of the AV valves?

Isovolumetric relaxation period

What describes:- A period of Ventricular diastole- AV valves open (Atria DID NOT CONTRACT YET) → Blood flow from atria to ventricles- Occurs during the first third of diastole- S3 can be heard at end of this period?

Rapid filling period

What heart sound:- End of rapid filling period of Diastole- Caused by abrupt cessation of ventricular distention and by deceleration of blood entering ventricles- Can be heard in children with thin chest walls and in pt with distended or noncompliant ventricle?

S3

What heart sound:- Occurs during last third of diastole when atria contracts?

S4

During the last third of diastole, the atria contracts, how much of the heart's blood filling does it contribute?

It adds 30% to the volume in the ventricles

Because there's no valves between Central veins (Vena Cava + Pulmonary), when does the atria fill with blood?

Continuously during both systole and diastole

What is the Conduction system consist of?

- Sinoatrial (SA) node- Internodal pathways- AV node- Bundle of His- L & R bundle of Purkinje system

What part of the Conduction system:- Innervated by ANS (both sympathetic and Parasympathetic)- Located on Right atrium- Where rhythmic impulse is generated and send to Internodal pathway?

SA node

What part of the Conduction system:- Receives and DELAYS impulses from atria (via Internodal pathway) before sending it to ventricles via Bundle of His- Delay is used to help atria complete ejection of blood before ventricles contract?

AV node

What part of the Conduction system:- Transitional fibers that conducts (& DELAYS) impulse from Atria to ventricles; specifically to left and right bundle branches?

Bundle of His

What part of the Conduction system:- Fibers originate from AV node and travels down Bundle of His and divides into R and L bundle branches in the Ventricular Septum- Lies beneath Endocardium- Allow for rapid conduction and excitation of both R and L ventricles- Can be damaged by MI, can't contract dead tissues?

Purkinje fibers

What describes:- Pumping activity of the heart fails but electrical activity continues- Say pt's heart is not pumping, but the monitor is still beating; thus we look at the pt rather than the monitor for dead or alive?

PEA (pulselessness electrical activity)

What are the 3 parts of Action potential?

- Resting / Unexcited state (Membrane is polarized = Pos outside membrane, Neg inside)- Depolarization (Change in polarity = Pos inside, Neg outside)- Repolarization (Reestablishment of polarity)

What describes:- The opening of Fast Na channels that occur in atria, ventricles, and Purkinje fibers- DOES NOT initiate cardiac muscle action potential, that's the SA node which opens slow Ca channels which conducts an impulse to the myocardial cells which will depolarize the cells and initiate phase 1?

Fast response(What the SA node did was the Slow response; watch Khan academy, it's easier to understand)

What describes:- Phase of Action potential of Myocardial cells- Occurs in Atrial and Ventricular muscle in the Purkinje conduction system- Opening of FAST Na channels for a few ten-thousandths of a sec = DEPOLARIZATION THRESHOLD- This cause rapid INFLUX of Na to interior of cell → Membrane potential shift Resting potential of -90 mV to +20 mV?

Phase 0 (Upstroke or Rapid depolarization)

What describes:- Phase of Action potential of Myocardial cells- Occurs at peak of action potential- Inactivation of FAST Na channels = Dec in Na permeability- K channels open → Membrane begins to decrease slowly from +20mV?

Phase 1 (Early Repolarization)

What describes:- Phase of Action potential of Myocardial cells- Caused by slower opening of Ca channels → Ca ions ENTERS MUSCLE (Ca has Positive action potential like Na)- In last phase K channels are open, causing Efflux of K. Remember that K has Negative action potential. So now that Ca is entering and K is leaving, the membrane potential remains steady or dec more slowly- Lasts few tenths of a sec = Action potential in Cardiac muscle lasts 3-15 times longer compared to Skeletal muscles = Inc period of contraction?

Phase 2 (The Plateau)

What describes:- Phase of Action potential of Myocardial cells- Begins with downslope of Action potential- Slow Ca channels close = Both Ca and Na influx cease- Inc K permeability → Rapid OUTWARD movement of K → Reestablishment of Resting potential = -90 mV- After reaching resting potential, distribution of Na and K returns to normal = Resting state?

Phase 3 (Rapid Repolarization)

What describes:- Phase of Action potential of Myocardial cells- Na-K pump adenosine triphosphate (ATPase) pump is activated → Na moves out + K moves back into the cell (undo electrolyte movements from other phases)- Action potential at steady -90 mV?

Phase 4 (Resting Membrane potential)