B1 - The external surface of the heart, its base and its structure

Question 1

Position of the heart

Answer 1

• Between 3^rd and 6^th rib in the thorax
  
  • Space between scapula and humerus
• Right auricle: Cranial and left
• Left auricle: Caudal and left
• Apex: Caudoventrally directed
• Margo ventricularis dexter: Cranial margin
• Margo ventricularis sinister: Caudal margin
• In pericardium
• In mediastinum
• Ru, Eq: Heart axis almost vertical
• Ca: Axsis more horizontal
  
  • Apex → diaphragma
• Sus: Axis more horizontal (like Ca)
  
  • Apex → sternum

Question 2

The external surface of the heart

Structures to mention

Answer 2

• Basis cordis
• Apex cordis
• On the cone:
  
  • Facies auricularis
  • Facies atrialis
  • Margo ventricularis dexter
  • Margo ventricularis sinister
• Sulcus interventricularis paraconalis
• Sulcus interventricularis subsinosus
• Sulcus coronarius
  
  • Truncus pulmonalis

Question 3

The external surface of the heart

1. Explain the structures
2. Draw the external surface of the heart

Answer 3

• Right venous and left arterial part
• On the cone:
  
  • Margo ventricularis dexter (convex)
  • Margo ventricularis sinister (concave)
  • Facies auricularis (facing left thoracic wall, left surface)
  • Facies atrialis (facing right thoracic wall, right surface)
• Sulcus coronarius (externally bound between the atria and ventricles. Contains coronary vessels and fat)
  
  • Truncus pulmonalis (interrupts sulcus coronarius)
• ​Sulcus interventricularis (separation of right and left ventricles)​
  
  • Sulcus interventricularis subsinosus (Longitudinal groove on facies atrialis outside of septum interventriculare, contains terminal part of a. coronaria)
  • Sulcus interventricularis paraconalis (Longitudinal groove in facies auricularis. Begins at base of tr. pulmonalis, caudal to conus arteriosus of right ventricle. Runs from sulcus coronarius to apex cordis. Contains paraconal interventricular branch of a. coronaria sinistra)

Question 4

Base of the heart

General

Answer 4

• The base of the heart is the hilus
• Location where veins enter and arteries leaves
• Facies atrialis (right) and facies auricularis (left) meets:
  
  • Cranially in margo cranialis dexter
  • Caudally in margo ventricularis sinister

Question 5

Base of the heart

Draw the base of the heart??

Answer 5

Transverse section through the atria in horse