What is the right atrium divided by and what is it divided into?
- it is divided by crista terminalis into rough anterior part & smooth posterior part
What is the extension of crista terminalis?
- crista terminalis extends from opening of superior vena cava to the opening of inferior vena cava & it is marked on the outer surface by a groove called sulcus terminales
What does the rough anterior part of the right atrium contain?
- contains muscular projections called musculi pectinati
What does the smooth posterior part of the right atrium receive?
- receives opening of the big veins
What does the interatrial septum contain?
- fossa ovalis: oval depression (marks the location of foramen ovale)
- annulus ovalis: a ridge surrounding fossa ovalis
What are the opening of the right atrium?
- Superior vena cava
- Inferior vena cava
- Coronary sinus: has a valve to prevent return of blood to coronary sinus
- Right atrioventricular opening: guarded by tricuspid valve
- Anterior cardiac veins
- Venae cordis minimae: smallest cardiac veins
Where does the superior vena cava open in the right atrium?
- opposite right 3rd sternocostal junction, has no valve
Where does the inferior vena cava open in the right atrium?
- opposite right 6th sternocostal junction, has
rudimentary valve
What are the characteristics of the cavity of the left atrium?
- its cavity is smooth except the left auricle which is rough as it contains musculi pectinate
What are the opening of the left atrium?
- 4 pulmonary veins: carry oxygenated blood from lung to heart
- Left atrioventricular opening: guarded by mitral valve
- Venae cordis minimae
Compare between the right ventricle and left ventricle according to:
Wall thickness
CS
Outflow part
Papillary muscles
Presence of moderator band
Wall thickness: Wall is thinner - Wall is 3 times thicker
CS: Semilunar in cross section - Circular in cross section
Outflow part: Outflow part is infundibulum - Outflow part is aortic vestibule
Papillary muscles: Has 3 papillary muscles ( ant., post. & septal) - Has 2 papillary muscles ( ant. & post.)
Presence of moderator band: Has moderator band - Has no moderator band
What are the characteristics of the upper out-flowing part of the right ventricle?
- is smooth and called infundibulum
What are the characteristics of the lower inflowing part of the right ventricle?
- rough and contains muscular ridges (trabeculae carnae)
What are the papillary muscles in the right ventricle attached to and what are they attached by?
- 3 papillary muscles (ant., post. & septal) are attached to the 3 cusps of tricuspid valve by tendinous bands called cordae tendinae
What does the moderator band in the right ventricle connect and what does it carry?
- it contains moderator band which connects the interventricular septum with the anterior papillary muscle. It carries the right branch of A-V bundle
What are the characteristics of the upper out-flowing part of the left ventricle?
- smooth and called aortic vestibule
What are the characteristics of the lower inflowing part of the left ventricle?
- rough and contains trabeculae carnae
What are the papillary muscles in the left ventricle attached to and what are they attached by?
- 2 papillary mmuscles (ant. & post.) are attached to the 2 cusps of mitral valve by chordae tendinae
Compare between tricuspid valve and mitral valve according to:
Connection
No. Of cusps
No of tips of fingers admitted
Site
Connection:
- Between right atrium & right ventricle
- Between left - atrium & left ventricle
No. Of cusps:
- Has 3 cusps: ant., post. & septal
- Has 2 cusps: ant. & post.
No of tips of fingers admitted:
- Admits tips of 3 fingers
- Admits tips of 2 fingers
Site:
- Opposite left 4th intercostal space
- Opposite left 4th sternocostal junction
Compare between the pulmonary valve and the aortic valve according to:
Connection
No and Site of cusps
Site
Connection:
- In upper part of right ventricle
- In upper part of left ventricle
No and Site of cusps:
- Has 3 cusps: one anterior & 2 posterior
- Has 3 cusps: one posterior & 2 anterior
Site:
- Opposite left 3rd sternocostal junction
- Opposite left 3rd intercostal space
What is the arterial supply of the heart?
1- Right coronary artery
2- Left coronary artery
What is the origin of right coronary artery?
- right aortic sinus of ascending aorta
What is the course of right coronary artery?
- pass between right auricle & pulmonary trunk then pass in coronary sulcus between right atrium & right ventricle
What are the branches of the right coronary artery?
1- to S-A node 65%
2- atrial branch to right atrium
3- marginal artery: along inferior border & supply right ventricle
4- posterior intervenricular artery: in the posterior interventricular groove Supplies: posterior wall of both ventricles Posterior third of interventricular septum
