Right atrium of heart

Right Atrium of human heart
This PPT help to understand the external and internal structures of right atrium.
sulcus terminalis on external surface of rt atrium,
crista terminalis on internal side of rt. atrium,
interior is divided into rough anterior part and smooth posterior part ( sinus venarum)
superior and inferior venae cavae drains deoxygenated blood into rt. atrim
there is Eustachian valve to guard the opening of IVC and Thebesian valve to guard the opening of coronary sinus
septal wall presents fossa ovalis with its border limbus fossa ovalis

1. Rt Atrium Dr Karle Geetanjali Professor, Rachana Sharir , PMT,s Ayurved College, Shevgaon

2. Introduction- Rt atrium is receiving chamber for deoxygenated blood. It receives deoxygenated blood from the superior and inferior vena cavae , from the coronary veins & from the venae cordis minimae . Rt atrium pumps the blood through the right atrioventricular orifice(guarded by the tricuspid valve) into the right ventricle . .

3. Location and contribution in parts of heart- The right atrium is somewhat quadrilateral chamber situated behind and to the right side of the heart. It is composed of a main cavity and a small anteriorly extending part called auricle. T he right atrium forms the right border of the heart. It contributes in the formation of anterior surface and base of the heart.

4. External Features- The right atrium receives superior vena cava (SVC) at its upper end and the inferior vena cava(IVC) at its lower end. The upper anterior part is prolonged to the left to create the right auricular appendage, the right auricle. The margins of the auricle are notched. The right auricle overlaps the roots of the ascending aorta and pulmonary trunk

5. Ext features conti .. Sulcus terminalis- A shallow vertical groove that extends along the right border of heart, in between the superior and inferior vena cavae . SA node is located at the upper part of this sulcus . Internally it corresponds to crista terminalis. The right atrioventricular groove lodges the right coronary artery and the small cardiac vein .

6. Internal structure of right atrium- The interior of the right atrium is divided into 2 parts: 1) smooth posterior part – the sinus venarum , 2) Rough anterior part – the atrium proper. smooth and rough parts are separated from each other by crista terminalis.

7. 1) Smooth part- Presents following structures- 1. Opening of SVC at upper end 2.Opening of IVC at lower end, this opening is guarded by semilunar valve or Eustachian valve . 3.Opening of coronary sinus- The coronary sinus receives blood from the coronary veins. It opens into the right atrium between the inferior vena cava and the right atrioventricular orifice. The opening of coronary sinus is guarded by coronary valve or Thebesian valve 4.Vanae cordis minimae are small openings of smallest cardiac veins

8. 2)Rough anterior part- anterior part is rough due to musculi pectinate, the muscle fibres running forward from crista terminalis. Musculi pectinate are numerous in auricle .

9. Septal wall of the right atrium- embryologically this part is developed from septum primum and septum secundum. The septal wall inside presents the following features: 1)Fossa ovalis, a shallow oval/saucer-shaped depression in the lower part, created by septum primum. – It represents the site of foramen ovale in the foetus . 2) Annulus ovalis/limbus fossa ovalis, creates the distinct upper and lateral margin of the fossa ovalis. – It represents the free edge of the septum secundum. 3). Triangle of Koch, a triangular area bounded in front by the base of septal leaflet of tricuspid valve, behind by anterior margin of the opening of coronary sinus and above by the tendon of Todaro- a endocardial ridge. – The atrioventricular node is located in this triangle

10. Thank you!!! Special thanks to my student Shruti Rasal for diagram of internal structure of rt atrium, Durva Pawar for diagram of ant. Veiw of heart