B2 - The left half of the heart

Question 1

The left half of the heart

Left atrium (**Atrium sinistrum)

Answer 1

• 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 2

The left half of the heart

Left ventricle (**Ventriculus sinistrum)

Answer 2

• 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)