Heart Ch. 20 Flashcards
In the pulmonary circuit the blood flows from which side of heart to where?
blood goes from right side of heart to lungs
In the pulmonary circuit the gas exchange occurs where and returns oxygen back to what?
gas exchange in lungs and returns oxynated blood back to heart
In the systamic circuit blood flows from which side of heart to where
blood goes from left side to organs
Where is the hear located?
mediastinum
How big is the heart?
about size of fist
Base of the heart is what?
superior
The Apex is where?
inferiorly and points to the left
The heart is enclosed in a double-walled sac called?
pericardium
What is the pericardial sac (parietal)
the outer wall of the heart that has a fibrous layer and a sereous layer.
The sereous layer of the pericardial sac turns inward at the base of the heart forming the what?
epicardium (visceral)
The space between the parietal and the visceral membranes is known as the what?
pericardial cavity
What 3 layers make up the heart wall?
epicardium, myocardium, endocardium
What is a serous membrane of the heart surface?
epicardium
What lines the interior of the heart chambers, covers the valves, and is continuous with the inner lining of the blood and is composed of simple squamous epithelium?
endocardium
What is composed of cardiac muscle and lies between the other two layers of the heart, composing the mass of the heart and has a vortex pattern that causes the heart to contract with a twisting or wringling motion that enhances the ejection of blood?
myocardium
Thin walled receiving chambers for blood returning to the heart by way of the great veins . Most of the mass is on the posterior side of heart.
Right and left atria
Each atrium has a small earlike extension called an _____ that slightly increases its volume
auricle
Thick walled, inferior pumping chambers that eject blood into the arteries and keep it flowing around the body.
right and left ventricle
What is the interventricular septum?
muscular vertical wall between the ventricles
When do atrioventricular (AV) valves close?
when ventricles contract
Which AV valve has three cusps and is therefor called the tricuspid valve?
right AV valve
What regulates the openings between the atria and ventricles?
atrioventricular (AV) valve
The left AV valve is known as the what valve?
mitral, formally called bicuspid valve
What connects the valve cusps to conical papillary muscles on the floor of the ventrical?
tendinous cords
What regulates the flow of blood from the ventricles into the great arteries?
semilunar valves
What makes up the semilunar valves?
pulmonary valve and the aortic valve
The valve that controls the opening from the right ventricle into the pulmonary trunk (exit of right ventricle)
pulmonary valve