06/07/2023 Notes Flashcards
What lines the heart valves and ensures unidirectional blood flow?
Endothelium
What is the fibrous skeleton of the heart?
Irregular dense connective tissue found between the atria and ventricles that separates them from each other, anchors heart valves, provide electrical insulation, and provides a rigid framework for attachment of cardiac muscle tissue
Why is it important to have electrical insulation in the heart?
Ensures that muscle impulses are not spread randomly and prevents the heart chambers from beating simultaneously
Where does the right atrium receive blood from?
Receives venous blood from systemic circulation and from heart muscle itself
Where does the superior vena cava drain blood from?
Head, neck, upper limbs, and upper regions of the trunk
Where does the inferior vena cava drain blood from?
Lower limbs and trunk
What drains blood from the heart wall?
Coronary sinus
What is the interatrial septum?
A thin wall between the right and left atria that contains the fossa ovalis
What is the fossa ovalis?
An oval depression in the interatrial septum that the occupies the former location of the foramen ovale
What is the right atrioventricular (AV) valve?
Tricuspid valve that is forced shut when the right ventricle contracts to prevent backflow of blood into right atrium
Where does deoxygenated blood from the right atrium travel to?
Through the tricuspid valve and into the right ventricle
What is the interventricular septum?
A thick wall between the right and left ventricles
What are trabeculae carneae?
Large, smooth irregular muscle ridges found on the internal walls of each ventricle
What are papillary muscles?
cone-shaped muscular projections that anchor chordae tendineae (thin strands of collagen fibers)
What do chordae tendineae do?
Attach to lower surfaces of cusps on the right AV valve and prevents the valve from everting and flipping into the atrium during contraction
What is the pulmonary semilunar valve?
Marks the end of the right ventricle and entrance into the pulmonary trunk
What are the pulmonary arteries?
Branches of the pulmonary arteries which carry deoxygenated blood to the lungs
semilunar valves are located in the walls of both _____.
Ventricles
What forms semilunar valves?
3 thin, half-moon shaped semilunar cusps
How do the semilunar valves/semilunar cusps work?
As blood is pumped into arterial trunks, it pushes against the cusps and forces the valves open, and when contraction ends, blood is prevented from backflowing by entering the semilunar valves between the cusps and chamber walls which causes the cusps to fill and expand