Chapter 20

A baby is born with an incomplete closure of the foramen ovale. Which of the following statements regarding blood flow throughout the baby's cardiovascular system would be true?

Blood would mix between the left atrium and right atrium.

Which of the following statements best describes the difference between fetal circulation and newborn circulation?

Fetal circulation bypasses the pulmonary circuit via the foramen ovale and the ductus arteriosus.

An aneurysm is

a sac-like widening or outpocketing of an artery.

The diameter of a typical capillary is similar to that of

an erythrocyte

Diverts blood from the pulmonary trunk to the aorta

ductus arteriosus

Blood pressure is highest in the

elastic arteries

Identify the vessel that branches off the brachiocephalic trunk in the cat and off the aortic arch in humans.

left common carotid artery

The right suprarenal and gonadal veins drain into the inferior vena cava, whereas the left suprarenal and gonadal veins drain into the

left renal vein

Diverts blood from the right atrium to the left atrium

foramen ovale

Which structure shunts blood from the right atrium to the left atrium in the fetal heart?

foramen ovale

Fenestrated capillaries

have pores in their walls.

Elastic arteries __________.

have the greatest diameter of all arteries and includes the aorta.

The circulatory route that runs from the digestive tract to the liver is called

hepatic portal circulation.

Which artery arises from the inferior part of the abdominal aorta and supplies the distal half of the large intestine?

inferior mesenteric artery

The right gonadal vein drains into the

inferior vena cava.

Present in most capillaries, these structures are absent in those of the blood-brain barrier.

intercellular clefts

The gaps of unjoined membrane through which small molecules exit and enter capillaries are called __________.

intercellular clefts

Which of the four vessels that branch off the subclavian artery supplies blood to structures in the thorax only?

internal thoracic artery

An aneurysm __________.

is a saclike widening and weakening along an artery

Which structure does NOT receive its blood from a branch off the celiac trunk?

jejunum

Blood passing through the fetal ductus arteriosus bypasses the

lungs, left atrium, and ventricle.

Precapillary sphincters allow blood to leave this structure and enter true capillaries.

metarterioles

Which of the following vessels is bypassed by the ductus venous in the fetal circulation?

most liver vessels

The superior mesenteric artery supplies __________.

most of the small intestines and the proximal half of the large intestine

Structure that regulates blood flow into true capillaries.

precapillary sphincter

Site-specific functions of capillaries include __________.

receiving digested nutrients in the small intestine removal of nitrogenous wastes from the kidneys exchange of oxygen and carbon dioxide in the lungs transporting hormones from endocrine glands ****All of the listed functions are site-specific functions of capillaries.

The foramen ovale in the heart normally closes

shortly after birth

In fetal circulation, the foramen ovale and ductus arteriosus __________.

shunt blood away from pulmonary circulation

Which of the following is not a branch of the celiac trunk?

sigmoidal artery

Wide leaky capillaries found in bone marrow and spleen.

sinusoids

__________ are wide, leaky capillaries that occur in regions where there is movement of large materials, such as proteins or cells, between blood and tissue.

sinusoids

Identify the vessel that receives blood from the upper limb.

subclavian vein

Which dural sinuses are located within the falx cerebri?

superior and inferior sagittal sinuses

Veins entering the right atrium include which of the following?

superior and inferior venae cavae and the coronary sinus

Which vessel is NOT part of the pulmonary circuit?

superior vena cava

Functionally, there are no valves in arteries (as opposed to in veins) because

the blood pressure in arteries is high enough that there is no backflow of blood.

The abdominal aorta divides at its distal end into which arteries?

the common iliac arteries

Most systemic venous blood is both oxygen-poor and nutrient-poor. However, systemic venous blood that is not oxygen-poor and is nutrient-rich occurs in

the hepatic portal vein.

The cerebral arterial circle forms a loop around which structures?

the pituitary gland and the optic chiasma

Most small molecules pass through a capillary wall through which route?

through intercellular clefts

In a capillary bed, relaxation of the precapillary sphincters causes more blood to flow

through the true capillaries

The elastic arteries are the largest arteries near the heart.

true

The saphenous vein is not paired with an artery with the same name.

true

Veins have less elastin in their walls than do arteries.

true

Capillaries consist of only this layer.

tunica intima

Which layer of an elastic artery contains the largest amount of elastic fibers?

tunica media

Which layer of blood vessels contains smooth muscle tissue?

tunica media

Vessel that carries blood from the fetus to the placenta

umbilical artery

Which pair of structures listed is INACCURATE?

umbilical artery; ligamentum teres

In the adult, the hepatic portal system carries nutrients absorbed from the digestive tract to the liver. In the fetus, nutrients are absorbed at the placenta, and the vessel that carries these nutrients to the liver is the

umbilical vein

Vessel that carries oxygenated blood from the placenta to the fetus

umbilical vein

Which vessel carries fetal blood with the highest concentration of oxygen?

umbilical vein

What prevents the backflow of blood in veins?

valves

Which structure helps to maintain the flow of blood in the type of vessel shown here?

valves

Which vessels merge to form the basilar artery?

vertebral arteries

By definition, veins are

vessels that carry blood toward the heart.

Two paired vessels supply blood to the brain: the internal carotid arteries and the vertebral arteries. From which vessels do these arteries originate?

Common carotid and subclavian arteries

What is the primary importance of the ductus venosus in the fetus?

It is a shunt that re-routes blood away from the portal system directly to the inferior vena cava.

What is the function of the first capillary bed of the hepatic portal system?

It picks up nutrients and toxins from capillaries in the stomach and intestines.

In a human, if the brachiocephalic trunk was narrowed with atherosclerosis, what additional pathways would be essential to maintain blood supply to the brain?

Left common carotid and left vertebral arteries

The hepatic portal system has two distinct capillary beds separated by a portal vein. What are the functions of these two capillary beds?

The first picks up digested nutrients, and the second delivers these nutrients to liver cells.

A common theme to the development of atherosclerosis is

an inflammatory response to a damaged endothelium.

The right and left vertebral arteries join to form the __________ at the region of the brain stem.

basilar artery

The correct proximal to distal sequence of the three vessels branching from the aortic arch is

brachiocephalic, left common carotid, left subclavian

Which branch (or branches) of the abdominal aorta supplies the stomach?

celiac trunk

What vessel in the fetus connects the pulmonary trunk to the aortic arch so that most of the blood bypasses the immature lungs?

ductus arteriosus

Carries blood from the umbilical vein through the liver into the inferior vena cava

ductus venosus

In metabolically active tissues, blood is present in metarterioles, and precapillary sphincters are constricted.

false

The inferior vena cava ascends on the left side of the vertebral bodies and to the left of the abdominal aorta.

false

Vessels of the small intestines, renal glomerulus, and synovial membranes that allow passage of fluid and solutes through "windows" in the endothelium.

fenestrated capillaries