Podcast
Questions and Answers
What is the origin of the Right Coronary Artery?
What is the origin of the Right Coronary Artery?
Which of the following structures is supplied by the Right Coronary Artery in approximately 60% of patients?
Which of the following structures is supplied by the Right Coronary Artery in approximately 60% of patients?
What is the largest branch of the Right Coronary Artery?
What is the largest branch of the Right Coronary Artery?
Which artery is typically associated with the Left Coronary Artery as its major branches?
Which artery is typically associated with the Left Coronary Artery as its major branches?
Signup and view all the answers
Which anatomical feature does the Left Coronary Artery emerge between?
Which anatomical feature does the Left Coronary Artery emerge between?
Signup and view all the answers
In which part of the heart does the Circumflex artery continue to supply?
In which part of the heart does the Circumflex artery continue to supply?
Signup and view all the answers
What is the term used to describe the connection between the Right Coronary Artery and the Circumflex artery?
What is the term used to describe the connection between the Right Coronary Artery and the Circumflex artery?
Signup and view all the answers
What coronary artery supplies the anterior interventricular area of the heart?
What coronary artery supplies the anterior interventricular area of the heart?
Signup and view all the answers
What is the primary location affected by a blockage in the Left Anterior Descending (LAD) artery?
What is the primary location affected by a blockage in the Left Anterior Descending (LAD) artery?
Signup and view all the answers
In a right dominant heart, which artery primarily supplies the posterior interventricular septum?
In a right dominant heart, which artery primarily supplies the posterior interventricular septum?
Signup and view all the answers
Which term is used to describe the occlusion in the LAD that often leads to high mortality?
Which term is used to describe the occlusion in the LAD that often leads to high mortality?
Signup and view all the answers
Which type of cardiac veins drain blood directly into the heart's chambers?
Which type of cardiac veins drain blood directly into the heart's chambers?
Signup and view all the answers
What is commonly associated with myocardial ischemia?
What is commonly associated with myocardial ischemia?
Signup and view all the answers
Which artery has the least likelihood of being occluded compared to other coronary arteries?
Which artery has the least likelihood of being occluded compared to other coronary arteries?
Signup and view all the answers
What is the main function of the coronary sinus in the heart?
What is the main function of the coronary sinus in the heart?
Signup and view all the answers
What percentage of patients typically exhibit right dominance in coronary artery supply?
What percentage of patients typically exhibit right dominance in coronary artery supply?
Signup and view all the answers
What initiates the electrical signal in the heart?
What initiates the electrical signal in the heart?
Signup and view all the answers
What is the primary function of the sympathetic supply to the heart?
What is the primary function of the sympathetic supply to the heart?
Signup and view all the answers
Where do the sympathetic fibers that supply the heart originate?
Where do the sympathetic fibers that supply the heart originate?
Signup and view all the answers
Which nerve conveys parasympathetic signals to the cardiac plexus?
Which nerve conveys parasympathetic signals to the cardiac plexus?
Signup and view all the answers
Which dermatome is commonly associated with referred pain from cardiac ischemia?
Which dermatome is commonly associated with referred pain from cardiac ischemia?
Signup and view all the answers
Where is the AV Node located?
Where is the AV Node located?
Signup and view all the answers
What type of pain is associated with irritation of the pericardium during cardiac ischemia?
What type of pain is associated with irritation of the pericardium during cardiac ischemia?
Signup and view all the answers
What part of the heart supplies the electrical signal to the ventricles?
What part of the heart supplies the electrical signal to the ventricles?
Signup and view all the answers
What event marks the closure of the semilunar valves during the cardiac cycle?
What event marks the closure of the semilunar valves during the cardiac cycle?
Signup and view all the answers
Which phase of the cardiac cycle allows for passive filling of the ventricles?
Which phase of the cardiac cycle allows for passive filling of the ventricles?
Signup and view all the answers
What percentage of the end diastolic volume is provided by atrial contraction?
What percentage of the end diastolic volume is provided by atrial contraction?
Signup and view all the answers
What heart sound may occur due to atrial pressure increase in hypertensive patients?
What heart sound may occur due to atrial pressure increase in hypertensive patients?
Signup and view all the answers
What follows the closure of the AV valves in the cardiac cycle?
What follows the closure of the AV valves in the cardiac cycle?
Signup and view all the answers
Study Notes
Right Coronary Artery
- Originates from the ascending aorta (right aortic sinus)
- Emerges between the right auricle and pulmonary trunk
- Runs downwards in the coronary sulcus
- Continues posteriorly in the same groove until it anastomoses with the Circumflex branch of the left coronary artery
Right Coronary Artery Branches
- Artery to SA Node & AV Node (supplies these nodes in ~60% of patients)
- Posterior descending artery (PDA) or Posterior Interventricular A. (supplies this artery in ~70% of patients)
- Right Marginal Artery
Left Coronary Artery
- Originates from the Ascending aorta (left aortic sinus)
- Emerges between the left auricle and pulmonary trunk, then runs in the coronary sulcus
- Divides into the Anterior interventricular (1) & Circumflex arteries (2)
- Circumflex artery continues in the coronary sulcus to the back of the heart and anastomoses with the terminal part of the right coronary artery
Left Coronary Artery Branches
- Left Anterior Descending Artery (LAD) or Anterior Interventricular A.
- Circumflex Artery (can supply SA node, AV node or PDA in a minority of patients)
- Left Marginal Artery branch from Circumflex artery
Clinical Anatomy
- Coronary blockage is most likely to occur in the LAD (~40-50% of all cases)
- Obstructs most of the blood supply to the left ventricle
- Often requires surgical bypass
Myocardial Ischemia
- Angina pectoris
- Myocardial Infarction
Right vs. Left Coronary Dominance
- RCA dominance is more common (~70% of patients)
- LCA dominance is less frequent
- Co-dominance (roughly equal contribution from LCA and RCA) is also less frequent
Venous Drainage of the Heart
- Coronary sinus: main vein of the heart
- Anterior cardiac veins: from the anterior wall of the right ventricle
- Smallest cardiac veins (venae cordis minimi)
Coronary Sinus
- Drains blood from heart tissue to the right atrium
- Tributaries include:
- Great Cardiac Vein: travels with the anterior interventricular artery (LAD)
- Middle Cardiac Vein: travels with the posterior interventricular artery (PDA)
Innervation of the Heart
- Sympathetic Supply (Fight or Flight): fibers originate in Intermedolateral cell column (IML) of spinal cord at T1-T5 level
- Parasympathetic Supply (Rest and Digest): Vagus Nerves (CN X) descend from the brain to enter the cardiac plexus
Cardiac Ischemia Pain
- Left chest wall/left upper limb pain (referred pain associated with T1-T5 dermatome)
- Left shoulder and neck pain (referred pain associated with C3-C5 dermatome)
Cardiac Plexus
- Sympathetic: Nerves that originate in T1-T5 level of spinal cord; synapse at the sympathetic trunk; cardiopulmonary splanchnic nerves then travel to the cardiac plexus
- Parasympathetic: Vagus Nerves (CN X) descend to feed into the cardiac plexus
Conducting System of the Heart
- SA Node initiates signal
- Signal is transmitted myogenically to the AV node
- Signal is then transmitted to the ventricles via the AV bundle in the ventricular walls regulating contraction of ventricles/papillary muscles
Ventricular Diastole
- Ventricular relaxation leads to a decrease in ventricular pressure, causing the closure of semilunar valves and producing the second heart sound (S2).
- During the isometric relaxation phase, all valves are closed, and the ventricles relax.
- The volume of blood remaining in the ventricles at this stage is known as the end-systolic volume (ESV), typically around 50 ml.
- The aortic dicrotic notch coincides with the closure of the aortic valve.
- Continued ventricular relaxation further reduces pressure, allowing the opening of the AV valves.
- Ventricles fill passively with blood, accounting for 70% of the end-diastolic volume (EDV).
- This passive filling produces the third heart sound (S3).
- As blood flows into the ventricles, atrial pressure decreases.
Atrial Systole & Diastole
- Atrial diastole occurs throughout most of the cardiac cycle, allowing for venous return.
- During atrial systole, the atria contract, completing ventricular filling and contributing 25-30% of the EDV, which typically reaches 120 ml.
- Atrial contraction increases atrial pressure, generating a wave on the pressure tracing (a wave).
- In hypertensive patients, atrial systole can produce the fourth heart sound (S4), although it is usually inaudible.
New Cardiac Cycle
- As ventricular systole begins, ventricular pressure rises above atrial pressure, leading to the closure of the AV valves.
- This initiates a new cardiac cycle, with the process repeating itself.
Pressure Volume Curve
- The pressure-volume curve visually represents the relationships between ventricular pressure and volume throughout the cardiac cycle.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on the anatomy and branches of the right and left coronary arteries. This quiz will cover their origins, pathways, and major branches. Perfect for students in cardiovascular studies or anyone interested in heart anatomy.
