Circulatory System

Question 1

What are the two components of the circulatory system?

Answer 1

The blood vascular system
The lymph vascular system

Question 2

What does a vessel do?

Answer 2

deliver blood to the body
regulate the flow of blood to the various organs

Question 3

Why must vessels be elastic?

Answer 3

to accomodate changes in blood volume during systole and distole

Question 4

what controls arteriole size?

Answer 4

the ANS

Question 5

Where is blood flow the slowest and why?

Answer 5

capillaries. allows nutrient and gas exchange

Question 6

What are the 3 layers of a vessel?

Answer 6

tunica intima
tunica media
tunica adventitia

Question 7

Function of large elastic arteries

Answer 7

to smooth out fluctuations of pressure and flow caused ventricular contraction

Question 8

function of medium muscular arteries?

Answer 8

to distribute and control blood flow to organs

Question 9

function of small arteries and arterioles

Answer 9

regulate blood flow to capillaries by vasoconstriction and vasodilation (ANS control)

Question 10

What are Vasa vasorum

Answer 10

Vasa vasorum (VV) are defined literally as vessels of vessels

Question 11

What are nervi vasorum

Answer 11

nerves which innervate arteries and veins

Question 12

What are the 3 different types of capillaries?

Answer 12

Continuous
Fenestrated
Sinusoidal

Question 13

What are continuous capillaries and where are they found

Answer 13

endothelium is continuous. only small molecules can pass through. found in muscle, skin, fat, nerve tissue

Question 14

What are fenestrated capillaries and where are they found

Answer 14

have lots of holes. allow small molecules through. found in gut, endocrine cells, kidneys

Question 15

What are sinusoidal capillaries and where are they found

Answer 15

have large open pores and are the “leakiest” of the capillaries. Allow blood cells to pass through. Found in bone marrow, lymph nodes, spleen.

Question 16

What type of capillaries are involved in gas exchange?

Answer 16

continuous capillaries

Question 17

The BBB (Blood Brain Barrier) is what type of capillary?

Answer 17

continuous

Question 18

what are the layers of venules?

Answer 18

mostly tunica intima and adventitia, not much media.

Question 19

What are the layers of small/medium veins?

Answer 19

Tunica intima and adventitia, and have tunica media with 2-4 smooth muscle layers

Question 20

What are the layers of large veins

Answer 20

All 3. Thin tunica media. adventitia can have considerable smooth muscle to maintain proper tension of the wall.

Question 21

do venules have valves?

Answer 21

no

Question 22

do small/medium veins have valves?

Answer 22

maybe

Question 23

do large veins have valves?

Answer 23

yes, often.

Question 24

how can you distinguish a vein from an artery?

Answer 24

larger lumen, irregular shape, and no distinct layers

Question 25

How does blood flow toward the heart in veins?

Answer 25

contraction of adjacent musculature and movement of organs

Question 26

describe epicardium

Answer 26

collagenous external covering of the heart

Question 27

describe myocardium

Answer 27

• middle, muscular layer of the heart wall
• bundles of cardiac muscle cells
• capillary network and lymph drainage
• houses mutiple cardiac (ANS) nerve conduction fibers

Question 28

describe endocardium

Answer 28

three layers: endothelium and subendothelial layer, subendocardial layer

Question 29

Heart valves are an extension of the ?

Answer 29

endocardium

Question 30

Where can you find purkinje fibers?

Answer 30

myocardium and subendocardium layer of the endocardium

Question 31

What do purkinje fibers do

Answer 31

promote rapid conduction of impulses from the AV node

Question 32

valve leaflets are an extension of the ?

Answer 32

endocardium

Question 33

what is the importance of the cardiac skeleton?

Answer 33

it’s what the myocardium attaches to

Question 34

What is the importance of SA and AV nodes?

Answer 34

SA node is the pacemaker system of the heart
AV node conducts APs from the atria to the ventricles