Chapter 6.1: Pulmonary and Systemic Circulation

Comprehensive practice questions covering blood vessel types, major arterial and venous pathways, and the dynamics of pulmonary and systemic circulation.

What is the primary transportation system within our bodies?

Blood.

What is the function of arteries and their largest examples?

They transport blood away from the heart; the largest are elastic, such as the aorta and pulmonary artery.

How do large arteries move blood after ventricles eject it?

They stretch when blood is ejected and then recoil, moving the blood along.

What are the structural characteristics of arteries?

They have thick muscular, elastic walls and are usually found deep along bones.

What is the function and structure of veins?

They transport blood back to the heart and have thin walls containing valves.

Where are veins typically located in the body?

Often on the surface, surrounded by skeletal muscle.

How is a venule defined?

A very small vein, especially one collecting blood from the capillaries.

What is the function and structure of capillaries?

They interconnect arteries to veins and have very thin walls that are 1 cell thick.

What is the effect of capillary sphincter muscles on blood pressure?

If all capillary beds were open at one time, blood pressure would decrease; if all were closed, blood pressure would increase.

What is the difference between an afferent arteriole and an efferent arteriole?

Afferent arteriole means the incoming arteriole, whereas efferent arteriole is the outgoing arteriole.

How large is the aorta compared to capillaries?

The aorta is almost the diameter of a garden hose, while it takes ten capillaries to equal the thickness of a human hair.

Which chamber of the heart does the aorta leave from?

The left ventricle.

What are the first branches of the aorta and what is their function?

The coronary arteries; they carry nutrients to the heart cells.

Why can the heart muscle not receive nutrients from the blood traveling through its chambers?

The muscle is too dense and thick, and the blood travels through it too aggressively and quickly.

In circulatory terminology, what is 'spent blood'?

Blood that has delivered oxygen to the cells and picked up carbon dioxide, making it low in $O_2$ and high in $CO_2$.

Where do carotid arteries branch from and what do they contain for homeostasis?

They branch off the aortic arch; they contain chemoreceptors for oxygen content and pressure receptors for blood pressure changes.

How does blood flow through the jugular veins back to the heart?

Through gravity, as they do not contain valves.

What is the function of the subclavian arteries and veins?

They travel under the clavicle; arteries carry blood to the arms (brachial artery) and veins carry blood away from the arms (brachial vein).

What is the function of the mesenteric arteries?

They branch off the aorta to bring blood to the digestive system organs and pick up newly digested nutrients.

What is the function of the hepatic portal vein?

It brings blood from the digestive tract to the liver.

Which vessel carries blood from the liver to the posterior vena cava?

The hepatic vein.

Where do the renal arteries branch from and what is their destination?

They branch off the dorsal aorta in the lumbar region and take blood to the kidneys.

To which vessel do the femoral veins eventually lead in the abdomen?

The inferior vena cava (at the level of the fifth lumbar vertebra).

Which specific veins collect 'spent' blood from the upper and lower body?

The anterior (superior) vena cava collects from the upper body, and the posterior (inferior) vena cava collects from the lower body.

What makes the pulmonary circuit unique regarding blood oxygenation?

It contains the only artery in the body carrying deoxygenated blood and the only vein carrying oxygenated blood.

What is the path of the pulmonary circuit starting from the right ventricle?

Right ventricle ightarrow pulmonary trunk ightarrow pulmonary arteries ightarrow lung capillaries ightarrow pulmonary veins ightarrow left atrium.

What chemical reaction occurs during internal respiration in the systemic circuit?

$CO_2 + H_2O$.

What is the relationship between cross-sectional area (CSA) and blood velocity?

As cross-sectional area increases, the velocity of the blood decreases.

In which blood vessel type is blood pressure lost and unable to be regained?

Capillaries.

Which vessel type has the highest blood pressure and which has the lowest?

Arteries have the highest; veins have the lowest.

Which vessel type has the highest cross-sectional area?

Capillaries.

What is the path of blood from the head to the toe?

Jugular vein to the vena cava to the right atrium to the right ventricle to the pulmonary artery to the lungs to the pulmonary vein to the left atrium to the left ventricle to the aorta to the iliac artery to the femoral artery.