L4 - Gross Anatomy Of Heart Flashcards
What is circulatory system
Cardiovascular system + Lymphatic system
What is cardiovascular system
- Heart
- Blood (5 litres)
- Blood vessels
Location of heart
2nd to 5th ICS
Deep to the sternum
2/3 of heart in left of median plane
Superior to diaphragm
Landmark: Apex of the heart
Left midclavicular line, 5th intercostal space
Landmark: Left and Right border of heart
Line between: Left border of heart: 1cm left edge sternum, 2nd left costal cartilage Apex of heart On left ventricle
Right border of heart:
1cm right edge sternum, 3rd right costal cartilage
1cm right edge sternum, 6th right costal cartilage
On right atrium
3 layers of wall of heart
- Endocardium (endothelial cells)
- Myocardium (cardiac muscle)
- Epicardium (connective tissues, with coronary arteries)
- Pericardium (Fibrous + Parietal + Sac + Visceral)
Epicardium = Visceral pericardium
Landmark: Transverse and Oblique Pericardial Sinus
Transverse Pericardial Sinus:
Between Aorta and Pulmonary artery anteriorly
Superior vena cava posteriorly
Oblique Pericardial Sinus:
Posterior to left atrium
Right atrium and right ventricle divided externally by
Left atrium and left ventricle divided externally by
Coronary sulcus
Features of Right atrium
Divided internally by Crista terminalis:
- Atrium proper (anterior with pectinate muscle)
- Sinus venarum (smooth posterior)
- Right atrium and left atrium divided by
2. Right ventricle and left ventricular divided by
- Interatrial septum, contains fossa ovalis
2. Interventricular septum, thinner upper membranous, thicker lower muscular
Right atrium receives blood from
- Superior and Inferior VC
2. Coronary sinus
Location of SA node and AV node
SA node: Lateral of superior cavo-atrial junction, deep to Crista terminalis
AV node: Right side of interatrial septum, junction of atria and ventricles
Features of right ventricle
- Trabecular carneae (irregular muscle projecting from inner surface of ventricle)
- Papillary muscle (anterior, posterior, septal)
- Chordae tendineae
- Septomarginal trabecula (carries part of AV bundle)
Features of left ventricle
- Trabeculae carneae
- Papillary muscle (anterior and posterior ONLY)
- Chordae tendineae
- No septomarginal trabecula
2 Types of Valvular disease
- Stenotic —> backing up of blood
2. Insufficiency —> regurgitation
Describe heart sound
Lub: S1, loudest at apex, when systole begin
Dub: S2, loudest at base (heard at Erb’s point), when diastole begin
Sequence of conduction system of heart
SA node (spread throughout atria)
—> AV node (impulse delayed)
—> AV bundle / Bundle of His
—> Purkinje fibre (spread throughout ventricles)
Components of cardiac skeleton
Dense connective tissue, fibrous skeleton
- Pulmonary ring
- Aortic ring
- Right fibrous ring (Tricuspid)
- Left fibrous ring (Mitral)
- Left and Right trigone
- Conus tendon
Functions of cardiac skeleton
- Anchor heart valve cusps
- Point of insertion of AV bundle
- Separate atria from ventricles
- Electrical insulation between atria and ventricles
Where does left and right coronary artery arise from?
Left: left aortic sinus (in left semilunar cusp)
Right: right aortic sinus (in right semilunar cusp)
What do left and right coronary arteries supply?
Left CA:
LA, LV, AV bundle, interventicular septum
Right CA:
RA, RV, SA node, AV node, interventricular septum
Where do left and right coronary arteries travel in?
Left CA: Anterior interventricular sulcus + Coronary sulcus
Right CA: Posterior interventricular sulcus + Coronary sulcus
What are the branches of left and right CA?
Left:
- LAD / Anterior interventricular branch
- Circumflex
- Left marginal (of circumflex)
Right:
- Posterior interventricular branch
- Sinuatrialnodal branch
- Right marginal (of RCA)
4 Cardiac veins
- Great (along anterior interventricular sulcus, parallel LAD)
- Middle (along posterior interventricular sulcus, parallel posterior interventricular branch)
- Small (with right CA and right marginal artery)
- Posterior (with left marginal artery)
- Anterior
- Smallest
ALL drains into coronary sinus —> right atrium except Anterior and Smallest
Location of cardiac plexus
Base of the heart
Sympathetic and parasympathetic nerves for cardiac muscle
Sympathetic: T1 to T4 segments
Parasympathetic: Vagus nerve
Position of left auricle
Wrapped anteriorly between root of pulmonary trunk and LA