Section 48.3.1 (Exam 4) Blood Flow Flashcards
Heart Function Depends on properties of Cardiac Muscle
What are arteries?
vessels that carry blood away from the heart
What are arterioles?
branches of arteries that feed blood into the capillary bed
What are capillaries?
tiny thin-walled vessels that allows for exchange of material between blood and the interstitial fluid
What are venules?
small vessels that drain capillary bed
What are veins?
venules join to form larger vessels that bring blood to heart
What are the two circuits that mammals and birds have as a part of their CV system?
The pulmonary and systemic circuit
What happens within the pulmonary circuit?
blood is pumped from the heart to the lungs to be oxygenated which then returns to the heart
What happens within the systemic circuit?
blood is pumped from the heart to the rest of the body and back to the heart
Describe the human heart.
It has 4 chambers, two atria and two ventricles
What is the role of the right atrium (RA)?
receives deoxygenated blood from the systemic circuit
What is the role of the right ventricle (RV)?
pumps deoxygenated blood through the pulmonary circuit
What is the role of the left atrium (LA)?
receives oxygenated blood from the pulmonary circuit
What is the role of the left ventricle (LV)?
pumps oxygenated blood through the systemic circuit
How does the heart prevent the backflow of blood?
One-way valves
What are the 4 one-way valves present near the heart?
The two atrioventricular (AV) valves (between atria and ventricles) are internal valves. They prevent backflow when ventricles contract
Right AV valve: Tricuspid valve
Left AV valve: Bicuspid or mitral valve
The two external valves are the pulmonary valve (to the lungs) and aortic valve (to the aorta) prevent backflow when ventricles relax
Describe the full path of blood, detailing whether it is oxygenated or deoxygenated, and mention every valve and the name of the major vessels it comes into contact with. Also include details regarding the systemic circuit and how arteries and veins utilize the capillary bed.
Deoxygenated blood from the body enters the right atrium through the superior and inferior vena cava, then flows through the tricuspid valve into the right ventricle, which pumps it through the pulmonary semilunar valve into the pulmonary trunk and the pulmonary arteries towards the lungs.
Oxygenated blood returns to the heart via the pulmonary veins into the left atrium, then passes through the bicuspid (mitral) valve into the left ventricle, which pumps it through the aortic semilunar valve into the aorta.
The aorta branches into smaller arteries, which further split into arterioles that carry blood to the capillary beds where nutrient, gas, and waste exchange occurs.
Oxygen-rich blood then flows into venules, which converge to form veins. These veins return the deoxygenated blood to the heart through the superior and inferior vena cava, completing the cycle.
What is the difference between the superior and inferior vena cava?
Both deliver deoxygenated blood to the heart
The superior vena cava delivers blood from the upper body and the inferior vena cava delivers blood from the lower body
Ventricle walls have powerful muscles. Why are the left ventricle walls thicker than the right ventricle walls?
Because the left ventricle pushes blood to the whole body rather than just the lungs
