Chapter 20 - The Heart - PART 2 Flashcards
What is the function of the atria?
to collect blood that is returning to the heart and convey it to the ventricles
The demands of the left and right atrium are ___
similar
What is the relationship in APPEARANCE between the left and right ventricle
they look almost identical
The demands of left and right ventricle are ____
very different (and they also have significant structural differences)
The right ventricle pushes blood through which circuit?
the pulmonary circuit
Why does the right ventricle not have to work very hard to push blood through the pulmonary circuit?
Because the lungs are close to the heart and the pulmonary blood vessels are short and wide
The muscular wall of the right ventricle is relatively _____
thin
____ to ____ times as much pressure must be exerted to push blood around the systemic circuit as around the pulmonary circuit
4-6 times as much pressure must be exerted
The muscular wall of the left ventricle is extremely _____
thick
The pressure generated by the left ventricle contraction is more than enough to do what?
to open the aortic valve and eject blood into the ascending aorta
The right ventricle has a ____ like shape
pouch
As the powerful left ventricle contracts, it bulges into….
the right ventricular cavity
“As the left ventricle contracts, it bulges into the right ventricular cavity.”
this makes the right ventricle more _____
efficient
Why is it that individuals with severe damage to the right ventricle may still survive?
because the contraction of the left ventricle helps push blood into the pulmonary circuit
the heart has ___ pairs of ___way valves
the heart has…
TWO pairs of ONE-WAY valves
What is the purpose of the 2 pairs of one way valves?
to prevent the backflow of blood as the chambers contract
The atrioventricular (AV) valves prevent the backflow of blood from the ____ to the ____ when the _____ are contraction
AV valves prevent the backflow of blood from the VENTRICLES to the ATRIA when the VENTRICLES are contracting
What 2 structures play an important role in the normal function of the AV valves?
the papillary muscles and the chordae tendineae
When the ventricles are relaxed, the chordae tendineae are _____, and the AV valves offer no _____ as blood flows from the atria into the ventricles
LOOSE, NO RESISTANCE
When the ventricles contract, blood moving back towards the _____ swing the _____ together, closing the ______
When the ventricles contract, blood moving back towards the ATRIA swing the CUSPS together, closing the VALVES
When the ventricles contract, the contraction of the ____ ____ tenses the ____ ____ , stopping the ____ before they swing into the atria
When the ventricles contract, the contraction of the PAPILLARY MUSCLES tenses the CHORDAE TENDINEAE, stopping the CUSPS before they swing into the atria
What would happen if the papillary muscles were damaged or if the chordae tendineae were cut?
REGURGITATION would occur
this is backflow of blood into the atria each time that the ventricles contract
What are the 2 semilunar valves?
The pulmonary and aortic valves
The semilunar valves prevent the backflow of blood from the ____ ____ and _____ into the right and left ______, respectively
the semilunar (aortic and pulmonary) valves prevent the backflow of blood from the PULMONARY TRUNK and AORTA into the right and left VENTRICLES
the pulmonary trunk is also known as the…..
pulmonary artery
do the AV valves need muscular braces?
yes