(7) Heart and Vascular System II (Dennis)

Question 1

Helpful flow chart to keep histology concepts straight:

Answer 1

Question 2

Walls of arteries and veins are composed of three layers called ________

Answer 2

TUNICS

Question 3

Arteries branch extensively to ________ in diameter

Answer 3

Decrease

Question 4

Veins merge repeatedly to _______ in diameter

Answer 4

Increase

Question 5

What is the red bracket indicating?

Left image is? Right Image is?

Answer 5

Tunica Intima

Left= Artery

Right = Vein

Question 6

The Tunica Intima is the…

Answer 6

Layer that is most closely associated with the lumen of the vessel

Question 7

What is this layer?

This layer is lined with…

Answer 7

Tunica Intima

*Single layer of squamous epithelial cells

Question 8

What are three distinguishing characteristics of Tunica Intima?

Answer 8

1. Endothelium
2. Basal Lamina
3. Subendothelial layer (internal elastic membrane)

Question 9

What is the red bracket indicating?

Left image is? Right Image is?

Answer 9

Tunica Media

Left= Artery

Right = Vein

Question 10

Tunica media is always thicker in…

Answer 10

ARTERIES by far

Question 11

What is the red bracket indicating?

Left image is? Right Image is?

Answer 11

Tunica Adventitia

Left= Artery

Right = Vein

Question 12

What are distinguishing characteristics of the Tunica Adventitia?

Answer 12

• Longitudinally arranged
• Few elastic fibers
• Vasa vasorum
• Nervi vasorum (vascularis)

Question 13

What is the vasa vasorum?

Answer 13

Vessels of tunica adventitia of large arteries and veins

Supply blood to the vascular walls themselves

Question 14

What is nervi vasorum?

Answer 14

ANS input that controls contraction of vascular smooth muscle

Question 15

Large arteries…AKA?

Answer 15

Elastic arteries!

Named that for the LARGE amounts of ELASTIN in them!

Question 16

What is a major component that large (elastic) arteries LACK?

Answer 16

NO FIBROBLASTS

Question 17

Medium arteries… AKA?

Answer 17

Muscular arteries!!!

*More smooth muscle, less elastin

*******PROMINENT INTERNAL ELASTIC MEMBRANE BECOMES APPARENT

Question 18

What are these?

Answer 18

Large (elastic) arteries

Question 19

What are these?

Answer 19

Medium (muscular) arteries

Question 20

What is a small artery identified with?

Answer 20

UP TO 8 layers of smooth muscle

Question 21

What is a arteriole identified with?

Answer 21

Has 1-2 layers of smooth muscle

Question 22

Function of arterioles?

Answer 22

Flow regulators for capillary beds

• Sympathetic innervation to tunica media causes vasoconstriction
• Parasympathetic innervation to tunica media causes vasodilation

Question 23

What is this?

Answer 23

Top (A)= Small artery

Middle (A) = Arteriole

Question 24

What is the smallest of all blood vessels?

Answer 24

Capillaries

Question 25

Capillaries are surrounded by a cell type called \_\_\_\_\_\_\_

Answer 25

Pericytes

Question 26

Function of **pericytes?**

Answer 26

Surround capillaries Contractile cells Controlled by NO Promote stability of capillaries

Question 27

Where are **endothelial cells found?**

Answer 27

lining capillary beds

Question 28

What are the three types of capillaries?

Answer 28

1. Continuous capillary 2. Fenestrated capillary 3. Discontinuous capillary

Question 29

What is a **metarteriole?**

Answer 29

First branch off the arteriole supplying tissue

Question 30

What is a **thoroughfare channel?**

Answer 30

Distal end of metarteriole (lacks smooth muscle)

Question 31

What are **precapillary sphincters?**

Answer 31

Regulate blood flow through the capillaries

Question 32

When sphincters are **relaxed**, capillary bed is...

Answer 32

WELL PERFUSEED

Question 33

When sphincters are **constricted...**

Answer 33

Blood bypasses capillary bed

Question 34

Veins have thinner walls than accompanying arteries, lumen is _______ than that of the artery; lumen of veins are often \_\_\_\_\_\_\_\_

Answer 34

Larger Collapsed

Question 35

What is this?

Answer 35

Postcapillary venule

Question 36

What is this?

Answer 36

Muscular venule

Question 37

What is this?

Answer 37

Small vein

Question 38

What is this?

Answer 38

Medium Vein

Question 39

What is this?

Answer 39

Large vein

Question 40

Structure on the right?

Answer 40

Medium vein

Question 41

What is this?

Answer 41

Large vein

Question 42

What is this?

Answer 42

Lymphatic capillaries

Question 43

How are endothelial cells held in place in lymphatic capillaries?

Answer 43

By **anchoring filaments**

Question 44

How do you distinguish a lymphatic vessel histologically from a vein?

Answer 44

Thinner walls, No blood