hi let's talk about the right ventricle in this video we'll discuss the structures unique to
the right ventricle so the right ventricle receives blood from the right atrium we can
see the orifice for the tricuspid valve there recall that there are anterior posterior and
septal cusps for the tricuspid valve as there are three cusps there's going to be
sets of cordy tendony tendinous cords which attach to those cusps and
connect them to extensions of the myocardium called papillary muscles now there are anterior
posterior and septal papillary muscles but there is no fidelity between the cordy tendineae from
any particular cusp to these papillary muscles so for instance anterior and posterior
cusps will have chordae tendineae that attach to both anterior and posterior papillary muscles
the anterior papillary muscle is the largest among the papillary muscles and it's the most anteriorly
oriented we can see that there as well as cordy tendiny from a cusp of the tricuspid valve there
in association with that is going to be a large extension of myocardium that cuts across
and we can see that here it's been cut the right ventricle called the septomarginal trabecula
septomarginal trabecula is also known as the moderator band it was first described by
leonardo da vinci and it was thought that it moderated the expansion of the right ventricle
we now know that it's a shortcut for the lion's share of the right bundle branch
as it cuts across to serve the wall of the right ventricle the walls of the ventricles are
very rough with ridges of muscle these are invaginations of the myocardium surrounded
by the endocardium called trabeculae carneae or meaty beams and we'll see this we'll have a better
opportunity to see it in the left ventricle we don't have a good view of it here in the right
ventricle there's also an interventricular septum it has muscular parts and membranous parts to it
and then finally as blood leaves the right ventricle we can see that here
it's heading towards the pulmonary valve and the pulmonary trunk
but the region here is called the conus arteriosus and it is very smooth-walled
so there isn't a whole lot of contraction that's occurring there we don't want a whole
lot of turbulence going through the valves and so that conus arteriosus is very smooth
in terms of the valves associated with the right ventricle we know there's the tricuspid valve
with its anterior posterior and septal cusp that's regulating blood in
and then there's the pulmonary valve which regulates blood out of the right ventricle
so during systole the atrioventricular valve the tricuspid valve is closed and the semilunar valve
is open during diastole it's the opposite the tricuspid valve is open and the
pulmonary valve is closed the chordae tendineae attaching to papillary muscles
are going to prevent the cusps of the tricuspid valve
from moving back into the atria so they hold them in place they don't actually close the cusp
interventricular pressure buildup does that but they do hold them in place and prevent the the
backwards regurgitation of the valves and blood with the valves so we've discussed the structures
that are peculiar to the right ventricle this is your summary slide thank you for your time