Lecture #28: Cardiovascular Histology

Question 1

What are the components of the endocardium?

Answer 1

Endothelium and Subendothelial Connective Tissue

Question 2

True or False:

The endocardium is not continuous with the tunica intima of the blood vessels entering and leaving the heart.

Answer 2

False - IS continuous with the tunica intima of the blood vessels entering and leaving the heart.

Question 3

What layer is located between the endocardium and the myocardium?

Answer 3

Subendocardium Layer

Question 4

What is contained within the subendocardium layer?

Answer 4

Nerves
Purkinje Fibers

**these are referred to as subendocardial fibers

Question 5

What do Purkinje Fibers function to do? Also, what type of cells are they?

Answer 5

Carry impulses to ordinary cardiomyocytes.

Large, modified, and specialized cardiac muscle cell.

Question 6

What makes up the myocardium?

Answer 6

Consists of cardiac muscle cells.

Question 7

What type of tissue lines the external surface of the epicardium?

Answer 7

The external surface of the epicardium is covered by simple squamous epithelium (mesothelium).

Question 8

What composes the fibroelastic connective tissue that is covered by the mesothelium?

Answer 8

Fibroelastic connective tissue containing adipose cells, nerves, and coronary vessels.

Question 9

What are the three cardiac tunics starting from the deepest layer?

Answer 9

Endocardium

Myocardium

Epicardium

Question 10

What type of fibers originate and insert into the cardiac skeleton?

Answer 10

Myocardial fibers originate and insert into the cardiac skeleton.

Question 11

What kind of tissue is the cardiac skeleton composed of?

Answer 11

Dense Collagenous Connective Tissue

Question 12

True or False:

Walls of all blood vessels except capillaries are characterized by three layers (tunics).

Answer 12

TRUE

Question 13

What are the components of the tunica intima?

Answer 13

> Endothelium and its basal lamina

> Subendothelial Connective Tissue

> Internal Elastic Membrane

Question 14

Is the endothelium and its basal lamina of the tunica intima found in all arteries and arterioles?

Answer 14

YES

Question 15

What factor does endothelial cells produce that are crucial in hemostasis?

Answer 15

Endothelial cells produce von Willebrands’s factor VIII.

Question 16

True or False:

Subendothelial CT of the tunica intima is found in all elastic and muscular arteries and some arterioles.

Answer 16

True

Question 17

Which type of arteries, elastic or muscular, has an incomplete internal elastic membrane?

Answer 17

Internal elastic membrane -> incomplete in elastic arteries but thick and complete in muscular arteries.

Question 18

What is the tunica media made up of?

Answer 18

Circular smooth muscle tissue

Fibroblasts

Question 19

Does the tunica media contain collagen and elastic fibers?

Answer 19

YES

Question 20

What tunica layer does arterioles not have?

Answer 20

Tunica adventitia

Question 21

In what tunica layer is vasa vasorum and nervi vasorum found?

Answer 21

Tunica adventitia

Question 22

What type of tissues does the tunica adventitia consists of and contain?

Answer 22

Consists of Loose Areolar Tissue

Contains Irregular Fibroelastic Tissue with Adipocytes

Question 23

Got to slide 13

Answer 23

sweet

Question 24

What does the endocardium, which is the innermost cardiac tunic (layer), line?

Answer 24

Endocardium -> innermost layer, lining the atria and the ventricles.

Question 25

Are muscular arteries typically distributing or conducting arteries?

Answer 25

Distributing Arteries

Question 26

Are elastic arteries typically distributing or conducting arteries?

Answer 26

Conducting Arteries

Question 27

True or False: Elastic arteries stretch during systole and recoil during diastole.

Answer 27

True

Question 28

Give 3 examples of elastic arteries that are found in the body?

Answer 28

Aorta Pulmonary Trunk Large Branches of Aorta

Question 29

What is the relationship between smooth muscle layer thickness and the diameter of the vessel?

Answer 29

Thickness of smooth muscle layer decreases as diameter becomes smaller.

Question 30

# Fill in the Blank: Tunica media consists of smooth muscle that responds to _______ stimulation and hormones.

Answer 30

autonomic

Question 31

How many layers of smooth muscle cells are typically found in the tunica media of arterioles?

Answer 31

1-3 layers of smooth muscle cells.

Question 32

True or False: Arterioles give rise to metarterioles which have a discontinuous layer of smooth muscle tissue.

Answer 32

True

Question 33

True or False: Pericytes are differentiated mesenchymal cells.

Answer 33

False - pericytes are undifferenetiated mesenchymal cells.

Question 34

True or False: Pericytes may be contractile and can serve as stem cells to differentiate into fibroblasts.

Answer 34

True

Question 35

Which type of capillary has a pericyte associated with it?

Answer 35

Continuous Capillary

Question 36

What are the three different capillary types?

Answer 36

Continuous, Fenestrated, and sinusoid (discontinuous capillary) capillaries.

Question 37

Which two capillaries have a continuous basal lamina and which one does not?

Answer 37

Continuous Basal Lamina -> continuous and fenestrated capillaries. Discontinuous Basal Lamina -> sinusoid (discontinuous) capillary

Question 38

Give examples of where continuous capillaries can be found in the body?

Answer 38

``` > muscle > brain > thymus > bone > lung > pancreas ```

Question 39

In which type of capillary would you expect to find caveolae and vesicles transporting substances through the cytoplasm in a bidirectional pathway (transcytosis)? HINT: the intra cytoplasmic vesicles are coated by the protein caveolin (haha).

Answer 39

Continuous Capillary

Question 40

Where are fenestrated capillaries found in the body?

Answer 40

They are present in tissues with substantial fluid transport: - intestinal villi (jejunum) - choroid plexus - ciliary processes of the eye - glomerular capillaries of the kidneys

Question 41

Are the gaps larger in fenestrated or discontinuous capillaries?

Answer 41

Discontinuous capillaries (sinusoid)

Question 42

Where are discontinuous capillaries commonly found in the body?

Answer 42

> Spleen -> endothelial cells are elongated and protrude into the lumen. > Liver

Question 43

True or False: The gaps in venous sinusoids of the liver are wider than the discontinuous capillaries.

Answer 43

True

Question 44

Does veins or arteries have a larger lumen? Also, how about the thickness of the vessel wall?

Answer 44

Veins have a larger lumen and thinner vessel walls.

Question 45

True or False: Larger veins do not have a layer of longitudinal smooth muscle in the inner aspect of the tunica adventitia.

Answer 45

False - larger veins have a layer of longitudinal smooth muscle in the inner aspect of the tunica adventitia.

Question 46

List the general 4 step overview of the formation of an atherosclerotic plaque.

Answer 46

1) Endothelial Cell Dysfunction 2) Formation of the Atherosclerosis Plaque 3) T-cells-macrophage Interaction 4) Fracture of the Plaque and Thrombosis