Microscopic Structure Of BV

Question 1

Large elastic arteries leave the

heart and branch to form

Answer 1

muscular arteries.

Question 2

muscular arteries branch further
and enter—— , where they
branch much further to form

Answer 2

organs

arterioles

Question 3

arterioles branch into the

smallest vessels, the———

Answer 3

capillaries

Question 4

capillaries are

Answer 4

the site of exchange between
blood and surrounding tissue.

smallest vessels

Question 5

Capillaries then merge to form

Answer 5

venules

Question 6

Venules merge further into—-
and then———sized
veins.

Answer 6

small

medium

Question 7

small
and then medium vein leave organs, form
————which eventually
bring blood——

Answer 7

larger veins

back to the heart.

Question 8

In the basic structure of any vessel there are three layers:

Answer 8

1) tunica intima (the inner layer)
2) tunica media
3) tunica adventitia /externa (The Outer layer)

Question 9

tunica intima

Answer 9

the inner layer: Endothelial cells and sub-endothelial connective tissue

Question 10

tunica media

Answer 10

elastic fibers and smooth muscles (thicker than intima )

Question 11

tunica adventitia /externa

Answer 11

The Outer layer: A connective tissue layer , continues with the connective tissues surrounding the blood vessel.

Question 12

Mention large elastic arteries?

Answer 12

the ascending / arch / descending aorta

Question 13

large size arteries ,and because of the ———they are also called elastic arteries

Answer 13

large amount of elastic fibers

Question 14

muscular arteries.

the tunica media of these arteries have

Answer 14

large amounts of smooth

muscles

Question 15

muscular arteries further divided into arterioles , which have a

Answer 15

very thin tunica media

Question 16

The capillaries is only an

Answer 16

endothelium supported by a basement membrane , no other layers

Question 17

small and then medium—sized veins (Have—- amount of muscles in Tunica media )

Answer 17

Less

Question 18

The most important feature in Large size veins (e.g. IVC) is the presence of

Answer 18

smooth muscle fibers in tunica externa (only in this type of veins)

Question 19

Walls of both arteries and veins have a—————,

Answer 19

tunica intima, tunica media, and tunica externa (or adventitia)

endoca

Question 20

artery has a thicker ——and relatively narrow——-.

Answer 20

tunica media

lumen

Question 21

vein has a larger——— and its——- is the thickest layer.

Answer 21

lumen

tunica externa

Question 22

The tunica intima of veins is often folded to form

Answer 22

valves.

Question 23

True or false

Capillaries have only an endothelium, with no subendothelial layer or other tunics.

Answer 23

T

Question 24

line the tunica intima

Answer 24

Simple squamous endothelial cells

Question 25

tunica intima has

Answer 25

-endothelial cells -subendothelial loose connective tissue

Question 26

tunica intima is separated from the tunica media by

Answer 26

internal elastic lamina (IEL)

Question 27

internal elastic lamina (IEL)

Answer 27

prominent sheet of elastin.

Question 28

The media (M) contains

Answer 28

elastic lamellae and fibers (EF) and multiple layers of smooth muscle

Question 29

The tunica media is—— in large arteries than veins, with relatively more elastin.

Answer 29

thicker

Question 30

Elastic fibers are also present in the tunica adventitia (A), which is relatively —-in large veins.

Answer 30

thicker

Question 31

Vasa vasorum (V) are seen in

Answer 31

adventitia of the aorta.

Question 32

The connective tissue of the adventitia always merges with the

Answer 32

less dense connective tissue around it.

Question 33

large elastic arteries tunica media consists mainly

Answer 33

elastic fibers

Question 34

if muscular arteries tunica media consists mainly

Answer 34

Smooth muscles fibers

Question 35

larger vessels, as the

Answer 35

aorta

Question 36

Walls of the larger vessels contain in the tunica adventitia a

Answer 36

supply of microvasculature to bring O2 and nutrients to local cells too far from the lumen to be nourished by blood there. -small sympathetic nerves (N) for control of vasoconstriction.

Question 37

constitute the vasa vasorum (vessels of | vessels).

Answer 37

arterioles (A), capillaries and venules (V)

Question 38

The largest arteries contain

Answer 38

1-considerable elastic material and expand with blood when the heart contracts. 2-thick tunica media (M) consisting largely of many well developed elastic lamellae.

Question 39

Strong pressure of blood pulsating into such arteries during systole

Answer 39

expands the arterial wall, | reducing the pressure and allowing strong blood flow to continue during diastole.

Question 40

intima (I) of the empty aorta is typically—— and the adventitia (A) contains

Answer 40

folded vasa vasorum.

Question 41

``` medium sized artery shows a—— tunica media (M) consisting largely—— ```

Answer 41

thick | smooth muscle fibers.

Question 42

Why so large sized arteries need elastic | the fibers ?

Answer 42

?

Question 43

Microvasculature arises to?

Answer 43

nutritional | needs of one organ or parts of one organ

Question 44

Microvasculature consists of blood vessels of

Answer 44

less than 0.5 mm | diameter.

Question 45

Microvessels include

Answer 45

arterioles metarterioles( arterioles smaller branches)

Question 46

Microvessels include arterioles and their smaller branches called metarterioles in which the layer of smooth muscle cells is dispersed as bands of cells that act as?

Answer 46

precapillary sphincters.

Question 47

The distal portion of the metarteriole, sometimes | called a ——— and it lacks—-

Answer 47

thoroughfare channel, any smooth muscles muscle cells.

Question 48

The wall of capillaries lacks

Answer 48

smooth muscle cells | altogether.

Question 49

The precapillary sphincters allow blood to enter the ——in a ——manner for maximally efficient exchange of nutrients, wastes, O2, and CO2 across the capillary wall.

Answer 49

the bed of capillaries pulsatile

Question 50

Capillaries and the metarteriole converge as ——-, the last component of the microvasculature. Blood enters microvasculature well—oxygenated and leaves poorly oxygenated.

Answer 50

postcapillary venules

Question 51

——-make up the microvasculature where in almost every organ, exchange takes place between blood and the interstitial fluid of the tissues.

Answer 51

Arterioles (A), small capillaries (C) and venules (V)

Question 52

Arterioles are microvessels with a tunica intima (I) that consists only of the ——- in which the cells may have——

Answer 52

endothelium rounded nuclei.

Question 53

Arterioles have tunica media (M) with only———-, and usually——, inconspicuous adventitia (Ad).

Answer 53

one or two layers of smooth muscle thin

Question 54

Capillaries consist only of an endothelium rolled as a tube, across which molecular exchange occurs between blood and tissue fluid.

Answer 54

T

Question 55

Capillaries are normally associated with perivascular contractile cells called ——which have a variety of functions. The more—— nuclei belong to endothelial cells.

Answer 55

pericytes (P) flattened

Question 56

Capillary—- wall of one endothelial cell covered by an external lamina (arrows). Endothelial cells have numerous—— vesicles and their edges overlap and are bound tightly together with——-

Answer 56

thin transcytotic vesicles occluding junctions (J).

Question 57

Pericytes can proliferate to form ——-when a capillary is transformed into an——

Answer 57

smooth muscle cells arteriole or venule after tissue injury and repair.

Question 58

Types of capillaries

Answer 58

(a) : Continuous capillaries, (b) : Fenestrated capillaries (c) : Sinusoids

Question 59

Continuous capillaries, the most common type, have?

Answer 59

tight, occluding junctions sealing the intercellular clefts between all the endothelial cells to produce minimal fluid leakage

Question 60

Continuous capillaries, | All molecules exchanged across the endothelium must cross the cells by

Answer 60

diffusion or transcytosis.

Question 61

Fenestrated capillaries have——-, but perforations (fenestrae) through the endothelial cells——

Answer 61

tight junctions allow greater exchange across the endothelium.

Question 62

Fenestrated capillaries, external lamina is

Answer 62

continuous in both a and b

Question 63

Fenestrated capillaries are found in organs where molecular exchange with the blood is important, such as

Answer 63

1) endocrine organs, 2) intestinal walls, and 3) choroid plexus.

Question 64

Sinusoids usually have a

Answer 64

1) wider diameter 2) discontinuities between the endothelial cells, large fenestrae through the cells, 3) partial, discontinuous basement membrane.

Question 65

Sinusoids are found in organs where ———and cells occurs readily between tissue and blood, such as in

Answer 65

exchange of macromolecules bone marrow, liver, and spleen.

Question 66

Continuous capillary

Answer 66

tight or occluding junctions | Numerous transcytotic vesicles are evident (small arrows).

Question 67

Fenestrated capillaries are specialized for uptake of molecules such as——— or for outflow of molecules such as in the—-

Answer 67

hormones in endocrine glands kidney’s filtration system.