12. Heart and Vascular System II

Question 1

What are the three layers that make up the walls of arteries and veins?

Answer 1

Tunica intima
Tunica media
Tunica Adventitia (externa)

Question 2

Tunica intima is closest to the lumen where the blood flows. What three things makes up this layer?

Answer 2

1. Endothelium
2. Basal lamina (with endothelial cells)
3. Subendothelial layer (with internal elastic membrane/lamina)

Question 3

The tunica media consists of arranged layers of smooth muscle. It extend from the internal elastic membrane/lamina of the tunica intima to the _________. it is thicker in arteries or veins?

Answer 3

to the external elastic membrane (layer of elastin that separates tunica media and adventitia

ARTERIES have thicker media

Question 4

The tunica adventitia/externa is longitudinally arranged collagenous tissue with few elastic fibers, merges with loose CT around the vessels. Is it thicker in arteries or veins?

Answer 4

Thickest in veins, relatives thin in arteries

Question 5

What are vessels of tunica adventitia of large arteries and veins within the tunica adventitia called? What are their function?

Answer 5

vasa vasorum

Supplies blood to the vascular walls

Question 6

What are nervi vasorum (vascularis)?

Answer 6

ANS input that control contraction of vascular smooth muscle in the tunica adventitia

Question 7

Large or Elastic arteries are the largest vessels of the artieral system. They have elastin that forms sheets/lamellae between muscle cell layers. They lack _______ so smooth muscle does what?

Answer 7

they lack fibroblasts so smooth muscle synthesizes the collagen, elastin, and ground substance of ECM

Question 8

Medium or muscular arteries are off the large arteris and have much more smooth muscle and less elastin than larger arteries. What is the hallmark of this?

Answer 8

Prominent internal elastic membrane apparent along with a recognizable external elastic membrane

* larger adventitia, smaller media*

Question 9

How many layers of smooth muscle in the tunica media do small arteries have, which also have an internal elastic membrane?

Answer 9

up to 8 layers, greater than 2

Question 10

How many layers of smooth muscle in the tunica media do arterioles have? What will they NOT have?

Answer 10

1-2 layers of smooth muscle (thinner)
DONT have (commonly) internal elastic membrane

Question 11

What are the KEY fucntions of arterioles as flow regulators for capillary beds?

Answer 11

Sympathetic innervation to tunica media = vasoconstriction
Parasympathetic innervation to tunica media= vasodialation
***and dialate to 60-100 percent its size and constrict to 40%

Question 12

Capillaries are the smallest blood vessels that form capillary beds. whose diameter is smaller than a RBC. They are surrounded by pericytes which do what?

Answer 12

Capillaries are IMPORTANT for nutrient exchange

Pericytes are contractile cells, it is enclosed in the basal lamina and controlled by NO, promoting stability of capillaries

Question 13

Endothelial cells form the innermost aspect of tunica intima, lining capillary beds. Connected via cell-cell junctions. What do they do metabolically?

Answer 13

Involved in blood coagulation and thrombosis, local vasodilation and constriction

Question 14

A capillary that has an endothelial cell lining with tight junctions. A uniform and complete basal lamina with pericytes would be considered what?

Answer 14

Continuous capillary

Question 15

A capillary that has fenestrations to allow some things to flow through, with a complete basal lamina, which can be found in the kidney or endocrine can be considered what?

Answer 15

Fenestrated capillary

Question 16

A capillary that has a discontinuous basal lamina with large sinusoids or holes in the endothelial lining, allowing anything to flow in or out, can be found in bone marrow or spleen— can be considered?

Answer 16

discontinuous capillary

Question 17

Metarterioles are the first branch off of arteriole supplying tissues (feeds capillary beds) which connects to a thorough fare channel which is?

Answer 17

The distal end of metarteriole (lacks smooth muscle), which connects to postcapillary venules

Question 18

True capillaries branch from metarterioles lack smooth muscle and have some pericytes. Between these and metarteioles there are precapillary sphincters which do what?

Answer 18

Regulate blood flow through the capillaries (open/close)

Question 19

A contracted precapillary sphincter will shunt blood flow which does what? (3)

Answer 19

prevents exchange within true capillaries
forces blood to enter venous return quickly
differentially occurs based on metabolic demand

Question 20

What is the flow of blood from venules to large veins like SVC, IFC and hepatic portal vein?

Answer 20

Venules from capillaries (postcapillary/muscular venules)
Small veins
Medium veins diameter as much as 10mm
Large veins >10mm

Question 21

What is important to remember of veins with their accompanying arteries?

Answer 21

They have thinner walls, lumer is larger than arterys’, lumen of veins collapse

Question 22

postcapillary have no tunica media, which drain to muscular venules which have 1-2 layers of what ?

Answer 22

smooth muscle in the tunica media with thin tunica adventitia

Question 23

Small venules have all 3 tunicas, with a thicker ______ and a 2-3 layer______?

Answer 23

Thicker adventitia and 2-3 layer media

Question 24

Medium veins travel with medium (muscular) arteries. they ahve a thicker ______- and _______ and contain valves?

Answer 24

tunica media and adventitia

Question 25

In large veins, the _________ is the thickest layer of the vessel wall, which contains collagen, elastics fibers and fibroblasts. Also contains longitudinal ________?

Answer 25

tunica adventitia is thickest layer

contains longitudinal smooth muscle cells

Question 26

In large veins, the ________ and _________ are thin. Intima blends in with media, media has smooth muscle and collagen.

Answer 26

tunica media and tunica intima

Question 27

Lymphatic vessels circulate lymph through most parts of the body, they are unidirectional conveying fluid only from tissues. Where do they return lymph to?

Answer 27

venous supply

Question 28

Lymphatic capillaries are closed ended tubes found in capillary beds which overlap endothelial cells to form a 1 way valve for lymph. These opening are allowed by _______ and held in place by ______ which join to form lymphatic vessels

Answer 28

opening are allowed by incomplete basal lamina = increases permeability

Held in place by anchoring filaments which form lympathic vessels

Question 29

Lympathic capillaries drain to lymphatic vessels which have all tunicas and posses valves. Walls increase in thickness as vessel increases in size. _______ prevent leakage.

Answer 29

Tight junctions

there are afferent and efferent lympathic vessels

Question 30

What is the flow of lymph from lymphatic capillaries to bachiocephalic vein to drain into?

Answer 30

Lymphatic capillaries
Lymphatic vessels
Lymphatic trunks
Right lymphatic duct (for right side head neck limb thorax)
Thoracic Duct (entire body + left side)
Veins