Lecture 1: Cardiac Anatomy Flashcards
Two parts of the mediastinum
- Superior
- Inferior
Superior mediastinum
-Above plane between sternal angle and inferior border of T4 vertebral body
Inferior mediastinum
- Anterior
- Middle
- Posterior
2 layers of the pericardium
- Fibrous
- Serous
The serous pericardium divides into two layers:
- Parietal layer
- Visceral layer
Sympathetic innervation of the heart
- T1-T4–“cardiac accelerators”
- Stellate ganglia (cervicothoracic ganglia) and middle cervical ganglia
- Distributed throughout the heart
Parasympathetic innervation of the heart
- Originates in the medulla oblongata
- Vagus nerves
- Much innervation to SA and AV nodes
- Little innervation to ventricles
Cardiac conduction system
- SA node
- AV node
- Bundle of His (AV bundle)
- Bundle branches (right and left branches)
- Purkinje fibers
Interatrial conduction pathways
-SA to LA
Internodal conduction pathways
-SA node to AV node
Divisions of the left bundle branch
- Left anterior division
- Left posterior division
Where is the AV node located?
-on the right side of the interatrial septum near the ostium of the coronary sinus
4 chambers of the heart
- right/left atria
- right/left ventricles
Vena Cavae on right side of heart
- Superior
- Inferior–Eustachian valve
Crista terminalis
- Divides the right atrium:
- Right atrial appendage (right auricle); trabeculated
- Smooth portion of atrium around vena cavae
Coronary sinus
-venous drainage of the heart
Fossa ovalis
-Remanent of foramen ovale
Tricuspid valve
-Right side of heart
Right ventricle structure
- Coarsely trabeculated inlet
- Smooth outlet–right ventricular outflow tract (RVOT)
- Thin-walled compared to LV
- Crescent-shaped in cross-section
RVOT
-right ventricular outflow tract–smooth outlet of the right ventricle
The left atrium contains ___ pulmonary veins
- 4
- return oxygenated blood from lungs back to the heart
What can form in the left atrial appendage in patients with a-fib?
-Thrombus formation in the left atrial appendage is a problem in patients with atrial fibrillation
Left ventricle structure
- Thick wall
- Circular in cross-section
- Anterior and posterior papillary muscles
What is the common wall between the RV and LV?
-Ventricular septum
What does the aortic valve separate?
-Separates left ventricle and aorta
The aortic valve is located on the same plane as ___
-Mitral and tricuspid valves
How many leaflets does the aortic valve have?
-3 leaflets = trileaflet
What are the sinuses of valsalva?
-Dilatations of the ascending aorta that occur just above the aortic valve
What originates from the sinuses of valsalva?
-Right and left main coronary arteries
Sinotubular junction
-The region of the ascending aorta between the aortic sinuses of Valsalva and where the normal tubular configuration of the aorta is attained
What does the mitral valve separate?
-Separates left atrium from left ventricle
How many leaflets does the mitral valve have, and what are they called?
- 2 leaflets
- Anterior leaflet
- Posterior leaflet
Anterior leaflet of the mitral valve
-Wide and short
Posterior leaflet of the mitral valve
-Narrow and long
Papillary muscles and chordae tendinae
- Muscles located in the ventricles of the heart
- Attached to the cusps of the AV valves (mitral and tricuspid valves) via the chordae tendinae to prevent valvular prolapse (blood flow from the ventricle into the atria during ventricular systole)
What does the tricuspid valve separate?
-Separates the right atrium from the right ventricle
How many leaflets does the tricuspid valve have, and what are they called?
- 3 leaflets:
- Anterior
- Posterior
- Septal
Pulmonary valve separates…
-the right ventricle from the pulmonary artery
How many cusps does the pulmonary valve have and what are they called?
-3 cusps, called the sinuses of Valsalva
What are the sinuses of valsalva?
-Dilatations of the main pulmonary artery which occur just above the pulmonic valve
Right coronary artery
-Dominance: in 85% of individuals, the RCA supplies the posterior descending artery (PDA)
The left main coronary artery bifurcates to form:
- Left anterior descending (LAD)
- Left circumflex
What are the two main coronary arteries?
- Right coronary
- Left coronary
What kind of branches does the left anterior descending artery have?
-Diagonal
What kind of branches does the left circumflex artery have?
-Obtuse marginales
What is the ramus intermedius?
-The additional branch in people who have a tri-furcation of their left main coronary artery
