B1 - The heart from without, the left half of the heart

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 heart from without

Answer 2

• 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 3

The left half of the heart

Left atrium (**Atrium sinistrum)

Answer 3

• Thicker walls than atrium dexter
• Receives atrial blood from vv. pulmonales
• The septal wall have fossa ovale (from fetal for. ovale)
• Auricula sinistra (extends around caudal surface of tr. pulmonalis)
  
  • Mm. pectinati (on the wall of auricula sinistra)
• Valvula foraminis ovalis (floor of fossa ovalis)
• Ostia venarum pulmonalium (entrance of vv. pulmonales into left atrium)
• Separated from right ventricle through septum interatriale​
• Vv. cordis minimae (supplies the wall)

Question 4

The left half of the heart

Left ventricle (**Ventriculus sinistrum)

Answer 4

• Receives blood from left atrium, pumps it thorugh the aorta into systemic circulation
• Forms the apex cordis
• Separated from atrium sinistrum through valvula bicuspidale covering the ostium atrioventriculare sinister
• Walls are thicker than in the right atrium
• Trabecula charnae
• Trabecula septomarginalis (from septum to the base of the 2 papillary muscles)
• Papillary muscles:
  
  • M. papillaris subauricularis
  • M. papillaris subatrialis
• Valves (named either: valva atrioventricularis sinister, valva bicuspidalis, valva mitralis)
  
  • ​2 cusps:
    
    • Cuspis septalis
    • Cuspis parietalis
• Valva aorta, 3 cusps: (keeps the blood from ventricle separated form blood in aorta)
  
  • Valvula semilunaris septalis
  • ​Valvula semilunaris dexter
  • ​Valvula semilunaris sinister
• Lig. arteriosum (Connection between pulmoary trunk and aorta, caudal to a. subclavis sinistra. Fetal: ductus arteriosus)
• Ositum atrioventriculare sinistrum (opening between left and right atrium)
• Valva atrioventricularis sinistra
  
  • ​Cuspis septalis
  • Cuspis parietalis
• Ostium aortae (opening of left ventricle into aorta ascendens)
• Valva aortae (attacehed on anulus fibrosus of ostium aortae)
  
  • Valvula semilunaris septalis
  • Valvula semilunaris dextra
  • Valvula semilunaris sinistra
  • Noduli valvularum semilunarum
  • Lunulae valvularum semilunarum
• M. papillaris subauricularis (located on parietal wall)
• M. papillaris subatrialis (located on parietal wall)
• Trabecula septomarginalis sinistrae (septum interventricularis → mm. papillaris)