CVS Anatomy of the heart Flashcards
What is the structure and function of the pericardial sac?
Outer fibrous layer:
- inferiorly blends with diaphragm
- holds heart in place
- bound to sternum by sternopericardial ligament
- prevents over filling
- a physical barrier to protect the heart from infection (eg from lungs close by)
Outer parietal layer
Inner serous layer
- attaches to heart and great vessels
- lubrication of heart
What is the relationship between the pericardial sac and the phrenic nerves?
There is a right and left phrenic nerve C 3 4 5 keeps you a-live Motor and sensory to the diaphragm Sensory to the pericardium Descends anterior to lungs, and over the right and left atrium
What makes up the \_\_\_\_\_\_\_\_ of the heart? left border right border inferior surface anterior surface posterior surface
Left border - left ventricle
Right border - right atrium
Inferior surface - right ventricle
Anterior surface - right atrium and ventricle
Posterior surface - left atrium and ventricle
What are the names of the coronary arteries and where do they arise from?
The coronary arteries are the first branches of the aorta and arise from the left and right aortic sinuses. The aortic sinuses pass around opposite sides of the pulmonary trunk
- right coronary artery
- left coronary artery
What parts of the heart does the right coronary artery supply and what are its major branches?
Supplies: RA, SA and AV nodes, posterior part of inter ventricular septum
Major branches:
- sinuatrial nodal branch
- right marginal branch
- atrioventricular nodal branch
- posterior interventricular branch
Describe the course of the right coronary artery on the anterior surface of the heart
Anterior surface:
Travels in right atrioventricular groove passing posteriorly between RA and RV.
Gives off the sinuatrial nodal branch then continues down atrioventricular groove and gives off right marginal branch. The right marginal branch supplies the right border of the heart and it runs towards the apex (does not reach the apex).
The right coronary artery then turns left and continues in the atrioventricular groove to the posterior aspect of the heart.
Describe the course of the right coronary artery on the posterior surface of the heart
Posterior surface:
At the junction between the 4 chambers (the crux) the R coronary artery gives off the atrioventricular nodal branch. Then it gives rise to the posterior inter ventricular branch which descends in-between the ventricles supply adjacent areas of both ventricles. It sends off inter ventricular septal branches into the septum.
What parts of the heart does the left coronary artery supply and what are its major branches?
Supplies: most of LA and LV, interventricular septum, atrioventricular bundles
Major branches:
- left anterior descending artery
- interventricular septal branches
- diagonal artery
- circumflex branch
- left marginal branch
Describe the course of the left coronary artery on the anterior surface of the heart
The LCA runs down the left atrioventricular groove where it splits into 2 branches:
LAD runs in the interventricular groove to the apex, where it turns around the inferior border and anastomoses with the posterior interventricular artery. LAD supplies adjacent parts of ventricles and the septum via the inter ventricular septal branches. The LAD sometimes gives off the diagonal artery which runs down the anterior surface.
The other branch of the LCA is the circumflex branch which follows the atrioventricular groove to the posterior.
Describe the course of the left coronary artery on the posterior surface of the heart
The left marginal branch of the circumflex artery runs down the left margin of heart and supplies LV.
In most people the circumflex artery terminates in the AV groove.
Give an brief overview of the venous drainage of the heart and list the major veins
The heart is drained by veins that empty into the coronary sinus and partly small veins that drain into RA.
- The coronary sinus is the main vein
- Great cardiac vein
- Middle cardiac vein
- Small cardiac vein
- Anterior cardiac veins
Describe the position and function of each of the major cardiac veins
The coronary sinus runs from left to right in the posterior atrioventricular groove
The great cardiac vein - the first part (anterior interventricular vein) begins at the apex and ascends with the anterior IV branch of the LCA. Turns left at AV groove and runs with circumflex branch of LCA to reach the coronary sinus.
The middle cardiac vein - accompanies posterior IV branch of LCA
The small cardiac vein - accompanies right marginal branch of RCA
The anterior cardiac veins - begin over anterior surface of RV, cross the AV groove and end directly in the RA (not via the coronary sinus)
What is the auscultation position for the 4 heart valves?
Aortic valve - 2nd IC space right sternal edge
Pulmonary valve - 2nd IC space left sternal edge
Tricuspid valve - 5th IC space left sternal edge
Bicuspid valve - 5th IC space mid-clavicular line
What is pericarditis?
Inflammation of the pericardium which is a sharp pleuritic (worse on breathing) pain
Pain may radiate to the top of trapezius - dermatomes
What is cardiac tamponade?
Fluid, blood, gas or pus fills the pericardial sac (pericardial effusion) which is unable to stretch due to fibrous CT
This compresses the heart and stops it beating
Treated with pericardiocentesis - drain using a needle
