NPLEX 1 LATEST 2026 EXAM TEST PAPER QUESTIONS AND
ANSWERS GRADED A+
✔✔2. 4-week-old male with a ventricular septal defect develops infective endocarditis
and experiences fever, septic emboli within his lungs. Which pathogenic bacteria is
most likely the cause of his sepsis? A. Streptococcus viridans B. Staphylococcus
aureus C. Haemophilus influenzae D. Staphylococcus epidermis - ✔✔▪ 2. A -
Streptococcus viridans is more common in patients with congential heart disease such
as ventricular septal defect. ▪ Endocarditis due to Staphylococcus aureus infection is
often secondary to an infection elsewhere. ▪ Haemophilus influenzae and
Staphylococus epidermis are not implicated in endocarditis
✔✔▪ Internal iliac supplies the... - ✔✔pelvic organs and muscles
✔✔ Key regulating enzyme for the synthesis of cholesterol? - ✔✔HMG-CoA reductase
✔✔The membranous interventricular septum is formed by ________? - ✔✔Endocardial
cushions
✔✔The __________ grows downward from the upper wall of the atrium to the right of
the primarly septum and ostium secundum. Shortly after birth it fuses with the septum
primum and results in the closure of the foramen ovale. - ✔✔septum secundum
✔✔Foramen Ovale becomes what in the adult? - ✔✔fossa ovalis
✔✔Ductus venosus becomes what in adult? - ✔✔ligamentum venosum
✔✔Ductus arteriosus becomes what in adult? - ✔✔ligamentum arteriosum
✔✔Umbilical vein becomes what in adult? - ✔✔ligamentum teres
✔✔Umbilical arteries become what in adult? - ✔✔medial umbilical ligament
✔✔What brings blood to the fetus? oxygenated blood - ✔✔umbilical vein
✔✔Major external and internal structures are developed but only minimally functional by
weeks _____ - ____? - ✔✔4-8
✔✔DEOXYgenated blood away fetus - ✔✔umbilical artery
✔✔vertical groove that separates the rough and smooth parts of the arterial wall,
externally - ✔✔Sulcus terminalis
, ✔✔same as above but internally - ✔✔Crista terminalis
✔✔smooth space between the openings of the SVC and IVC. - ✔✔Sinus venarum
✔✔muscular ridges in the atria - ✔✔pectinate muscles
✔✔depression on the interatrial septum - ✔✔fossa ovalis
✔✔Atrioventricular orifice is found on the top of the_____________. - ✔✔tricuspid valve
✔✔is found in the superior end of the sulcus terminalis near the opening of the SVC -
✔✔Sinoarterial node (aka pacemaker)
✔✔is found on the ventricular side of interartrial septum near the coronary sinus -
✔✔Artrioventricular node
✔✔opening between right AV and IVC orifices - ✔✔Coronary sinus
✔✔Left atrium - ✔✔▪ Forms the base of the heart▪ Shares the fossa ovalis with the right
atrium ▪ Interatrial septum▪ A.V. orifice (top of the mitral valve)▪ Left auricle
▪ Contains the entrance of the right and left pairs of pulmonary veins
✔✔RIGHT VENTRICLE - ✔✔▪ Trabeculae carnae = muscular elevations in the heart
wall
▪ Chorae tendinae attach the septal cusps of the AV valves to the ventricle walls
▪ Papillary muscles attach the tendinous cords to the ventricular walls
▪ Anterior, posterior, and septal
▪ Conus arteriosis is a conical prolongation of the right ventricle where the pulmonary
arteries emerge.
▪ Septomarginal trabecula carries the right bundle branch of the AV bundle
▪ Interventricular septum = muscular wall that separates the left and right ventricles
▪ Pulmonary trunk exits the right ventricle
✔✔Left ventricle - ✔✔Main pump of the heart
▪ Walls are thick due to the high pressure
▪ Papillary muscles
▪ Chordae tendinae
▪ Mitral valve
▪ Interventricular septum
▪ Trabeculae carnae
▪ Left bundle branch
▪ AV bundle - conducts impulses from the AV node
✔✔S1 sound - ✔✔Closure of the mitral and tricuspid (AV) valves (isometric contraction)
ANSWERS GRADED A+
✔✔2. 4-week-old male with a ventricular septal defect develops infective endocarditis
and experiences fever, septic emboli within his lungs. Which pathogenic bacteria is
most likely the cause of his sepsis? A. Streptococcus viridans B. Staphylococcus
aureus C. Haemophilus influenzae D. Staphylococcus epidermis - ✔✔▪ 2. A -
Streptococcus viridans is more common in patients with congential heart disease such
as ventricular septal defect. ▪ Endocarditis due to Staphylococcus aureus infection is
often secondary to an infection elsewhere. ▪ Haemophilus influenzae and
Staphylococus epidermis are not implicated in endocarditis
✔✔▪ Internal iliac supplies the... - ✔✔pelvic organs and muscles
✔✔ Key regulating enzyme for the synthesis of cholesterol? - ✔✔HMG-CoA reductase
✔✔The membranous interventricular septum is formed by ________? - ✔✔Endocardial
cushions
✔✔The __________ grows downward from the upper wall of the atrium to the right of
the primarly septum and ostium secundum. Shortly after birth it fuses with the septum
primum and results in the closure of the foramen ovale. - ✔✔septum secundum
✔✔Foramen Ovale becomes what in the adult? - ✔✔fossa ovalis
✔✔Ductus venosus becomes what in adult? - ✔✔ligamentum venosum
✔✔Ductus arteriosus becomes what in adult? - ✔✔ligamentum arteriosum
✔✔Umbilical vein becomes what in adult? - ✔✔ligamentum teres
✔✔Umbilical arteries become what in adult? - ✔✔medial umbilical ligament
✔✔What brings blood to the fetus? oxygenated blood - ✔✔umbilical vein
✔✔Major external and internal structures are developed but only minimally functional by
weeks _____ - ____? - ✔✔4-8
✔✔DEOXYgenated blood away fetus - ✔✔umbilical artery
✔✔vertical groove that separates the rough and smooth parts of the arterial wall,
externally - ✔✔Sulcus terminalis
, ✔✔same as above but internally - ✔✔Crista terminalis
✔✔smooth space between the openings of the SVC and IVC. - ✔✔Sinus venarum
✔✔muscular ridges in the atria - ✔✔pectinate muscles
✔✔depression on the interatrial septum - ✔✔fossa ovalis
✔✔Atrioventricular orifice is found on the top of the_____________. - ✔✔tricuspid valve
✔✔is found in the superior end of the sulcus terminalis near the opening of the SVC -
✔✔Sinoarterial node (aka pacemaker)
✔✔is found on the ventricular side of interartrial septum near the coronary sinus -
✔✔Artrioventricular node
✔✔opening between right AV and IVC orifices - ✔✔Coronary sinus
✔✔Left atrium - ✔✔▪ Forms the base of the heart▪ Shares the fossa ovalis with the right
atrium ▪ Interatrial septum▪ A.V. orifice (top of the mitral valve)▪ Left auricle
▪ Contains the entrance of the right and left pairs of pulmonary veins
✔✔RIGHT VENTRICLE - ✔✔▪ Trabeculae carnae = muscular elevations in the heart
wall
▪ Chorae tendinae attach the septal cusps of the AV valves to the ventricle walls
▪ Papillary muscles attach the tendinous cords to the ventricular walls
▪ Anterior, posterior, and septal
▪ Conus arteriosis is a conical prolongation of the right ventricle where the pulmonary
arteries emerge.
▪ Septomarginal trabecula carries the right bundle branch of the AV bundle
▪ Interventricular septum = muscular wall that separates the left and right ventricles
▪ Pulmonary trunk exits the right ventricle
✔✔Left ventricle - ✔✔Main pump of the heart
▪ Walls are thick due to the high pressure
▪ Papillary muscles
▪ Chordae tendinae
▪ Mitral valve
▪ Interventricular septum
▪ Trabeculae carnae
▪ Left bundle branch
▪ AV bundle - conducts impulses from the AV node
✔✔S1 sound - ✔✔Closure of the mitral and tricuspid (AV) valves (isometric contraction)
