Heart Flashcards
Why does the heart have blood vessels?
they transport blood between the heart and tissues
Arteries (away)
carry blood (high oxygen) away from the heart (except pulmonary arteries)
Veins (back)
carry blood (low oxygen) back to the heart (except for the pulmonary veins)
Arteries and veins are called the ______ vessels
Great
The heart ensures the _______ flow of blood through the heart and vessels.
unidirectional
What prevents the backflow of the blood?
Valves within the heart
One side of the heart
directs blood to the lungs for gas exchange
Other side of the heart
directs blood to body tissues for nutrient delivery
Where does the heart develop blood pressure?
through alternate cycles of heart wall contraction and relaxation
Why is blood pressure essential?
to push blood through blood vessels to the body tissues for nutrient and waste exchange
The pulmonary circuit consists of what chambers?
right atrium and ventricle
What does the pulmonary circuit do?
reduce carbon dioxide and replenish oxygen levels in the blood
When does blood return to the left side of the heart?
where it enters the systemic circuit
The systemic circuit consists of what chambers?
left atrium and ventricle
What does the systemic circuit do?
carries blood to all the peripheral organs and tissues of the body
______ blood from the left side of the heart is pumped into the _____
Oxygenated, aorta
Where does gas exchange in tissues occur?
capillaries
Most veins ______ into the ________ venae cavae, which drain blood into the right atrium.
There, the blood enters the _______, and the cycle repeats
merge and drain, superior and inferior, pulmonary circuit
Where is the heart located?
left of the body midline posterior to the sternum in the middle mediastinum.
What is base?
The posterosuperior surface of the heart
What is the apex?
The inferior, conical end of the heart
Where is the heart contained in?
in a fibrous, serous sac held in place within the mediastinum by connective tissue
What does the Pericardium do?
Restricts heart movements so that it doesn’t bounce and move and prevents the heart from overfilling with blood
What is fibrous pericardium?
a dense connective tissue layer that is tough (outer portion)
What is serous pericardium?
double-layered, inner portion membrane
The heart wall has 3 distinctive layers what are they?
external epicardium
middle myocardium, and
internal endocardium
What is the epicardium layer?
Epicardium is the outermost heart layer
AKA visceral layer of serous pericardium.
What is the myocardium layer?
Myocardium is the middle layer (Is the thickest of all 3)
and is made of cardiac muscle tissue
The external heart is composed of two smaller _____ and two larger ______.
atria, ventricles
What are atrias?
are thin-walled chambers
Atria receive blood returning to the heart through both circulatory circuits
What does the right atrium do?
receives blood from the systemic circuit
What does the left atrium do?
receives blood from the pulmonary circuit
the _____ trunk and the ____ exit the heart at the basal surface
pulmonary, aorta
The ______ trunk carries blood from the _____ ventricle into the pulmonary circuit
pulmonary, right
The _____ conducts blood from the _____ ventricle into the systemic circuit
aorta, Left
What are the atria and ventricles separated by?
deep coronary sulcus
What are the four internal heart chambers?
right atrium
right ventricle
left atrium
left ventricle
What do valves do?
permit the passage of blood in one direction and prevents its backflow
What does the right atrium do?
Receives venous blood from the systemic circuit
Three major vessels empty into the right atrium
What does the Right Atrioventricular (AV) Valve do?
Separates the right atrium from the right ventricle.
Aka the tricuspid valve
When is the right atrioventricular valve forced closed?
when the right ventricle begins to contract, preventing blood backflow into the right atrium
What does the right ventricle do?
Receives deoxygenated venous blood from the right atrium
The interventricular septum forms a wall between?
the right and left ventricles
What are papillary muscles?
The internal wall surface of each ventricle
What do the papillary muscles do?
anchor chordae tendineae
What does the pulmonary semilunar valve mark?
the end of the right ventricle and the entrance into the pulmonary trunk
Pulmonary blood carries what?
Deoxygenated blood to the lungs
What does the left atrium do?
the oxygenated blood travels through the pulmonary veins to the left atrium
What does the Left Atrioventricular (AV) Valve do?
Separates the left atrium from the left ventricle.
Aka bicuspid valve/mitral valve
What is the largest Ventricle? Right or Left?
Left
Why does the left ventricle have thick walls?
to generate pressure to force the oxygenated blood from the lungs into the aorta and then through the entire systemic circuit
