Cardiac Anatomy & Coronary arteries Flashcards
Describe the pericardium
3 layered sac
Fibrous pericardium: dense connective tissue
- protective layer
- attached to great vessels (aorta, pulmonary arter&vein)
- Attached to diaphragm
- Anchors heart in plcae
Serous pericardium
- Parietal attached to fibrous layer
- Visceral attached to surface of the hart (epicardium): allows the smooth movement of the myocardium- beats or movement of heart
What is the function of pericardium
- Fixes heart in mediastinum and limits movement
- Protection from infections coming from other organs (such as lungs)
- Prevents excessive dilation of heart in cases of acute volume overload
- Lubrication: allow free movement of heart with the pericardial sac
What is pericardial effusion/tamponade
Fibrous pericaridum:
- Normally restricts overexpansion
- But if fluid gathers between parietal and visceral pericardium the heart has no where to go
Accumulation of fluid under high pressure
Management: Pericardiocentesis
Indication for pericardiocentesis:
- A pericardial effusion causing tamponade (RV free wall collapse during diastole)
Decrease SV -> decrease CO-> hypotension/shock (reflex tachycardia)
incr
Describe the heart wall layers
- Epicardium
- Visceral layer of serous pericardium - Myocardium
- Cardiac muscle fibres: arranged in bundles, squeezes blood out of herat - Endocardium
- Continous with endothelium
- Lines chamgers and valves
Trace the flow of blood through the heart and identify the great vessels
Is the volume of blood propelled by the right ventricle the same as that
Superior vena cava, Inferior vena cava
Coronary sinus
Right atrium
Tricuspid valve
Right ventricle
Pulmonary semilunar valve
Pulmonary trunk
To lungs
Pulmonary capillaries
To heart
Four pulmonary veins
Left atrium
Mitral vavle
Left ventricle
Aortic semilunar vavle
Aorta
To body
Systemic capillaries
To heart
Describe the arrangement and the main features of the chambers of the heart
External landmarks
- Coronary groove (atrioventricular sulcus)
- Between atria and ventricles - Anterior interventricular sulcus
- Between right and left ventricle - Posterior interventricular sulcus
- Between right and left ventricle
What does the right atrium and the left atrium consist?
Right:
1. SVC,IVC
2. Right auricle
Left:
1. 4 pulmonary veins
2. Left auricle
Coronary groove: oblique plane which separates atria and ventricle
What does the right and left ventricle consist of?
Right:
1. 2/3 anterior
2. Pulmonary truncle
Left:
1. Apex (left border)
2. Inferior surface (2/3 post)
3. Aorta
Interventricular groove: overlies interventricular septum which separates left adn right ventricle
What does the right atrium and ventricle consist?
- Right border and anterior surface
- SVC,IVC and cornary sinus
- Smooth walled posteriorly, rough anteriorly
- Fossa ovalis:closed holes from the fetus stage (passes blood from right to left as it doesn’t need to go through the lungs)
- Tricuspid valve
- Valve cusps
- Cordae tendineae
- Papillary muscles - Trabeculae carnae
- Trabeculae: pole like, rod like cluster of blood vessels - Pulmonary trunk
What is the internal landmarks of the right atrium
- SVC
- Fossa ovalis
- IVC
- Cristae terminalis
- Pectinate muslce
- Tricuspid valve
What is the internal landmarks of the right ventricle
- Tricuspid valve
- Septal
- Chordae tendinae
- Trabeculae carnae
- Ant/Post. papillary muscle
- Moderator band
- Septal papillary muscle
- Pulmonary valve
- Pulmonary trunk
What does the left atrium and ventricle consist of?
- Posterior or base of heart
- 4 pulmonary veins
- Smooth walls excluding pectinate muslce in elft auricle
- Fossa ovalis
- Mitral valve: chordae tendineae, papillary muscle
- Trabeculae carnae
- Thicker myocardium
- Ascending aorta: aortic semilunar valve
What is the coronary blood supply?
Arterial supply
- Coronary arteries: right and left
Supply both the atria and ventricles
Coronary arteries
- Right anastomoses with circumflex branc of LCA
- After RCA has given rise to post interventricular artery - LAD loops around apex and anastomoses with post interventricular artery
- Dominance
- Determined by the artries that supply the posterior and inferior wall of the left ventricle
- Approximately 60% of the general population are right dominant, 25% are co-dominant and 15% are left-dominant