The Circulatory System

Question 1

The circulatory system includes

Answer 1

both the blood and
lymphatic vascular systems.

Question 2

The blood vascular
system is composed of

Answer 2

1. Arteries
2. Capillaries
3. Veins

Question 3

The arteries are

Answer 3

A series of efferent vessels that
become smaller as they branch.

Question 4

Function of arteries

Answer 4

To carry the blood, with its nutrients
and oxygen, to the tissues.

Question 5

The capillaries are

Answer 5

the smallest blood vessels,
constituting a complex network of thin tubules that
branch profusely in almost every organ and through
whose walls the interchange between blood and
tissues takes place.

Question 6

The veins result from

Answer 6

the convergence of
capillaries into a system of larger channels that
continue enlarging as they approach the heart,
toward which they convey the blood to be
pumped again.

Question 7

The lymphatic vascular system begins with

Answer 7

The
lymphatic capillaries

Question 8

The
lymphatic capillaries are

Answer 8

closed-ended tubules that merge to form vessels of
steadily increasing size

Question 9

Lymphatic capillaries empty into

Answer 9

the large veins near
the heart.

Question 10

The
internal surface of all components of the blood and
lymphatic systems is lined by

Answer 10

a single layer of a squamous
epithelium, called endothelium.

Question 11

The circulatory system is considered to consist of

Answer 11

1. The macrovasculature
2. The microvasculature

Question 12

Macrovasculature vessels are

Answer 12

More than 0.1 mm in diameter

1. Large arterioles
2. Muscular and elastic arteries
3. Muscular veins

Question 13

The microvasculature are

Answer 13

1. Arterioles
2. Capillaries
3. Postcapillary venules

Visible only with a microscope

Question 14

Circulatory functions of the lymphatic system is

Answer 14

to return the fluid of the tissue spaces to the blood.

Question 15

The walls of all four heart chambers consist of
three major layers or tunics:

Answer 15

1. The internal endocardium
2. The middle **myocardium **
3. The external epicardium.

Question 16

The endocardium consists of

Answer 16

A single layer of
squamous endothelial cells on a thin layer of loose
connective tissue containing elastic and collagen fibers
as well as some smooth muscle cells.

Question 17

The subendocardial layer connects

Answer 17

The subendothelial layer to the myocardium

Question 18

The subendocardial layer contains:

Answer 18

1. Veins
2. Nerves
3. Branches of the impulse-conducting system of the heart

Question 19

Which is the thickest tunic?

Answer 19

The myocardium

Question 20

The myocardium consists of :

Answer 20

cardiac muscle cells arranged in layers that surround the heart chambers in a complex spiral.

Question 21

The Epicardium is:

Answer 21

External covering of heart consisting of simple squamous epithelium (mesothelium) supported by a thin layer of connective tissue.

Question 22

A subepicardial layer of loose connective tissue contains

Answer 22

1. Veins
2. Nerves
3. Many Adipocytes

Question 23

The epicardium corresponds the layer of the percardium called:

Answer 23

The visceral layer

Question 24

There are two layers to the pericardial sac:

Answer 24

1. Fibrous pericardium (outermost layer)
2. Serous pericardium (innermost layer)

Question 25

The cardiac valves consist of

Answer 25

1. A central core of dense fibrous connective tissue (containing both collagen and elastic fibers)
2. Endothelial layers lining on both sides
3. The bases of the valves are attached to strong fibrous rings that are part of the fibrous skeleton.
4. The dense fibrous region around the heart valves anchors the base of the valves and is the site of origin and insertion of the cardiac muscle fibers

Question 26

The SA node is a small mass of modified cardiac muscle cells that are:

Answer 26

1. Fusiform
2. Smaller
3. Have fewer myofibrils than neighboring muscle cells.