AP Biology : Understanding Vasculature

Study concepts, example questions & explanations for AP Biology

varsity tutors app store varsity tutors android store

Example Questions

Example Question #1 : Understanding Vasculature

Larger arteries have less smooth muscle per volume when compared to smaller arteries (also called arterioles). What would you expect as a result of this distinction?

Possible Answers:

Arterioles are able to regulate blood pressure more efficiently than large arteries.

The smooth muscle is responsible for keeping the arterioles constricted at all times. 

Capillaries will have an even larger amount of smooth muscle per volume, because they are even smaller than arterioles.

Smaller arteries have more muscle tone, and are able to tolerate more pressure than large arteries.

Correct answer:

Arterioles are able to regulate blood pressure more efficiently than large arteries.

Explanation:

Smooth muscle is typically innervated by the sympathetic nervous system. Because arterioles have more smooth muscle per volume, they are able to respond to sympathetic innervation more efficiently than larger arteries. As a result, the smaller arteries are used to regulate blood pressure as well as reroute blood direction by adjusting arteriole diameter accordingly.

Example Question #1 : Circulatory Anatomy

The Bundle of His, part of the intrinsic conduction system, is best described as:

Possible Answers:

Purkinje fibers

the atrioventricular bundle

the SA node

the atrioventricular node

the pacemaker of the heart

Correct answer:

the atrioventricular bundle

Explanation:

Bundle of His is also known as the AV bundle.

The SA Node is located in upper right atrium. It initiates the depolarization impulse, which, in turn, generates an action potential that spreads via the internodal pathway situated in the walls of the atria to the AV node. From there, the impulse travels to the Bundle of His, then to the bundle branches and finally to the purkinje fibers.

Example Question #2 : Circulatory Anatomy

Which of the following vessels transports blood from the lungs to the heart?

Possible Answers:

Pulmonary arteries

Pulmonary veins

Aorta

Inferior vena cava

Superior vena cava

Correct answer:

Pulmonary veins

Explanation:

Veins carry blood to the heart, while arteries carry blood away from the heart. The pulmonary veins are the only veins in the body that carry oxygenated blood. It is important to remember not to confuse these veins with the pulmonary arteries, which carry deoxygenated blood from the heart to the lungs.

The aorta carries oxygenated blood from the heart to the systemic circuit for circulation throughout the body. The superior and inferior vena cavae return deoxygenated blood from the systemic circuit back to the heart.

Example Question #1 : Circulatory System

Which of the following vessels would be expected to have the lowest blood pressure in the human systemic circulation?

Possible Answers:

Arterioles

Arteries

Aorta

Venules

Capillaries

Correct answer:

Venules

Explanation:

The pressure decreases from the aorta to the arteries, arterioles, capillaries, and finally, the venules, veins, and vena cavae. Of the answer choices, the venules have the lowest pressure.

Example Question #1 : Understanding Vasculature

The heart pumps blood throughout the human body; however, it must pump at the right time and with the right amount of force. When the heart is not pumping efficiently and in a timely manner, the flow of blood becomes disrupted. One can think of the heart as the only traffic light in a busy intersection. When working properly, traffic flows smoothly. When is it not working properly, traffic becomes congested. Likewise, when the heart is weak, the blood leaving the heart towards the systemic circulation (e.g. brain, organs) becomes disrupted. The blood entering the heart from the lungs also gets congested because the heart is not able to pump fast enough and strong enough to get the blood in and out at the proper pace.

One of the most common causes of death for a patient with a weak heart is from pulmonary edema. Which of the following choices best explains how pulmonary edema may result from heart failure?

Possible Answers:

None of these

Pulmonary edema results from a problem with the lympathtic system which is largely dependant on the heart

Pulmonary edema results from blood being pushed back into the lungs from increased hydrostatic pressure in the vessels and capillaries 

Pulmonary edema results from an ion and iron deficiency in the blood 

Pulmonary edema results from an infection of the lungs

Correct answer:

Pulmonary edema results from blood being pushed back into the lungs from increased hydrostatic pressure in the vessels and capillaries 

Explanation:

When the heart is weak (e.g. heart attack), it is unable to pump as efficiently as before. Pulmonary edema occurs when the left ventricle is weak. This results in fluid to backing up and pooling into the lungs via the pulmonary vein. The backed up pressure increases the hydrostatic pressure of the vessels and capillaries in the lungs. The increase in hydrostatic pressure pushes the fluid in the blood towards the lungs, resulting in pulmonary edema.

Example Question #3 : Circulatory System

The migration of cells is necessary for proper development during fetal life. At around the third week of fetal development, hematopoietic stem cells can be found in the yolk sac as well as in the mesoderm of the aorta, the gonads and in the mesonephros. At around the 3rd month, these stem cells migrate to the liver with some to the spleen and the lymph node. At around the 4thmonth, these cells then migrate to the bone marrow.

When taking a cross section of a bone, one will notice that some bone marrows are red while others are fat. Yellow bone marrows are inactive stem cells with the majority being fat cells. Active bone marrows are red. At birth, all of the bone marrows are red. At around the time of puberty, most are red but the amount decreases to 50% at around 18-25 years of age. Despite the change in bone marrow activity, membranous bones and of the arms of and legs remain active throughout life. However, the activity can be changed during pathological conditions.

Extrameduallary hematopoiesis is when hematopoiesis occurs in other places than in the bone marrow. Which of the following scenario(s) may present as extrameduallry hematophiesis? 

I. Premature birth

II. Post-mature birth 

III. Severe hemorrhagic 

Possible Answers:

III only

I and III

II and III

II only

I only

Correct answer:

I only

Explanation:

A premature delivery, especially before the migration of the hematopoietic stem cells will result in extramedually hematopoiesis. 

Example Question #94 : Systems Physiology

The migration of cells is necessary for proper development of circulating cells during fetal life. At around the third week of fetal development, hematopoietic stem cells can be found in the yolk sac as well as in the mesoderm of the aorta, the gonads and in the mesonephros. At around the 3rd month, these stem cells migrate to the liver with some to the spleen and the lymph node. At around the 4thmonth, these cells then migrate to the bone marrow.

When taking a cross section of a bone, one will notice that some bone marrows are red while others are fat. Yellow bone marrows are inactive stem cells with the majority being fat cells. Active bone marrows are red. At birth, all of the bone marrows are red. At around the time of puberty, most are red but the amount decreases to 50% at around 18-25 years of age. Despite the change in bone marrow activity, membranous bones and of the arms of and legs remain active throughout life. However, the activity can be changed during pathological conditions.  

Hematopoietic stem cells allow for the development of which of the follow cells? 

I. White blood cells

II. Red blood cells

III. Platelets 

Possible Answers:

I and II only

I, II, and III

II only

III only

I only

Correct answer:

I, II, and III

Explanation:

As mentioned in the passage, hematopoietic stem cells lead to the development of cells which will circulate in the circulatory system. White blood cells, red blood cells, and platelets all circulate in the circulatory system. Although platelets are themselves not cells, they are fragments of cells that are created by hematopoietic stem cells.

Example Question #2 : Circulatory System

The migration of cells is necessary for proper development during fetal life. At around the third week of fetal development, hematopoietic stem cells can be found in the yolk sac as well as in the mesoderm of the aorta, the gonads and in the mesonephros. At around the 3rd month, these stem cells migrate to the liver with some to the spleen and the lymph node. At around the 4thmonth, these cells then migrate to the bone marrow.

When taking a cross section of a bone, one will notice that some bone marrows are red while others are fat. Yellow bone marrows are inactive stem cells with the majority being fat cells. Active bone marrows are red. At birth, all of the bone marrows are red. At around the time of puberty, most are red but the amount decreases to 50% at around 18-25 years of age. Despite the change in bone marrow activity, membranous bones and of the arms of and legs remain active throughout life. However, the activity can be changed during pathological conditions.  

Which of the following organ(s) will contain red bone marrow after 25 years old? 

Possible Answers:

Pelvic Bone

Spleen 

Kidney 

Femur 

None of these

Correct answer:

Femur 

Explanation:

Continued hematopoiesis only occur in axial bones, the femur (leg) and in the humerus bone (arm).  

Example Question #4 : Circulatory System

The migration of cells is necessary for proper development during fetal life. At around the third week of fetal development, hematopoietic stem cells can be found in the yolk sac as well as in the mesoderm of the aorta, the gonads and in the mesonephros. At around the 3rd month, these stem cells migrate to the liver with some to the spleen and the lymph node. At around the 4thmonth, these cells then migrate to the bone marrow.

When taking a cross section of a bone, one will notice that some bone marrows are red while others are fat. Yellow bone marrows are inactive stem cells with the majority being fat cells. Active bone marrows are red. At birth, all of the bone marrows are red. At around the time of puberty, most are red but the amount decreases to 50% at around 18-25 years of age. Despite the change in bone marrow activity, membranous bones and of the arms of and legs remain active throughout life. However, the activity can be changed during pathological conditions. 

What might be an unintended consequence of excess stimulation of hematopoietic stem cells? 

Possible Answers:

Decrease white blood cell count

Blood clot

Decrease red blood cell count

Decrease hematocrit 

None of these

Correct answer:

Blood clot

Explanation:

One of the purposes of stimulating hematopoietic stem cells is to to increase red blood cells production. However, excess red blood cells in the blood will increase the viscosity of the blood. With an increase in viscosity, the blood will not flow as fluid and will be prone to clots.  

Learning Tools by Varsity Tutors

Incompatible Browser

Please upgrade or download one of the following browsers to use Instant Tutoring: