Heart II Flashcards
What structures flowing into the right atrium have functional valves?
None. The IVC and the coronary sinus have valves, but they are not functional. The SVC does not have a valve
The terminal sulcus indicates the position of what?
the terminal crest, which is located on the inside of the right atrium under the terminal sulcus (the terminal sulcus is a ridge running from the SVC to IVC on the surface of the right atrium)
The smooth-walled portion of the right atrium is referred to as the?
sinus venarum
The sinus venarum is the remnant of what?
fetal sinus venosus
What structures enter the sinus venarum?
the SVC and IVC
The crista terminalis (internally, and sulcus terminalis externally) separates the sinus venarum from what part of the right atrium?
the original fetal atrium
The original fetal atrium has what structures associated with it?
ridges called pectinate muscles and also has the ear-like appendage called the auricle.
In utero, what shunts blood from the placenta directly from the right atrium to the left atrium?
foramen ovale (closes after birth)
What causes the foramen ovale to close at birth
pressure of the left atrium becoming higher than the right
What is the remnant of the foramen oval after birth?
the fossa ovalis and limbus of the fossa ovalis
What side of the heart is at higher pressure during development?
right. After birth, right side pressure becomes significantly reduced as the lungs expand, so left side pressure increases in a relative sense
What anchors the tricuspid valve?
Papillary muscles are attached to the edges of the valve leaflets by the chordae tendinae
What are the three cusps of the tricuspid valve?
anterior, posterior, and septal. Each cusp receives chordae tendinae from more than one papillary muscle
The conus arteriosus is aka?
infundibulum
What lines the walls of the right ventricle (not the bulbs cordis part)
trabeculae carneae (The remnants of the bulbus cordis are also smooth-walled)
The septomarginal trabecula is aka?
moderator band
What is the role of chordae tendinae and papillary muscles?
keeping the valve leaflets of the tricuspid valve from ballooning back into the right atrium, potentially allowing blood to regurgitate
The papillary muscles contract when the ventricles contract
The AV valve leaflets are too thin to function on their own without being anchored at their free border
What marks the boundary between the embryonic ventricle and bulbus cordis?
The supraventricular crest
T or F. The left atrial wall has a smooth surface, except for the auricle, which contains pectinate muscles
T