Section 48.3.1 (Exam 4) Blood Flow

Question 1

What are arteries?

Answer 1

vessels that carry blood away from the heart

Question 2

What are arterioles?

Answer 2

branches of arteries that feed blood into the capillary bed

Question 3

What are capillaries?

Answer 3

tiny thin-walled vessels that allows for exchange of material between blood and the interstitial fluid

Question 4

What are venules?

Answer 4

small vessels that drain capillary bed

Question 5

What are veins?

Answer 5

venules join to form larger vessels that bring blood to heart

Question 6

What are the two circuits that mammals and birds have as a part of their CV system?

Answer 6

The pulmonary and systemic circuit

Question 7

What happens within the pulmonary circuit?

Answer 7

blood is pumped from the heart to the lungs to be oxygenated which then returns to the heart

Question 8

What happens within the systemic circuit?

Answer 8

blood is pumped from the heart to the rest of the body and back to the heart

Question 9

Describe the human heart.

Answer 9

It has 4 chambers, two atria and two ventricles

Question 10

What is the role of the right atrium (RA)?

Answer 10

receives deoxygenated blood from the systemic circuit

Question 11

What is the role of the right ventricle (RV)?

Answer 11

pumps deoxygenated blood through the pulmonary circuit

Question 12

What is the role of the left atrium (LA)?

Answer 12

receives oxygenated blood from the pulmonary circuit

Question 13

What is the role of the left ventricle (LV)?

Answer 13

pumps oxygenated blood through the systemic circuit

Question 14

How does the heart prevent the backflow of blood?

Answer 14

One-way valves

Question 15

What are the 4 one-way valves present near the heart?

Answer 15

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

Question 16

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.

Answer 16

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.

Question 17

What is the difference between the superior and inferior vena cava?

Answer 17

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

Question 18

Ventricle walls have powerful muscles. Why are the left ventricle walls thicker than the right ventricle walls?

Answer 18

Because the left ventricle pushes blood to the whole body rather than just the lungs