Arrangement of Blood Vessels

Question 1

which blood vessel has the largest cross sectional area

Answer 1

capillaries

Question 2

which blood vessel has the smallest cross sectional area

Answer 2

aorta

Question 3

which blood vessel has the highest flow and which has lowest

Answer 3

highest= aorta

lowest=capillaries

Question 4

what are the 3 wall layers found in arteries and capillaries

Answer 4

tunica adventita
tunica media
tunica intima

Question 5

whats found in tunica adventia

Answer 5

collagen fibres

Question 6

whats found in tunica media

Answer 6

smooth muscle

elastin

Question 7

whats found in tunica intima

Answer 7

squamous epithelium- endothelium layer

Question 8

what are the wall layers found in cappillaries

Answer 8

endothelium and basement membrane

Question 9

what blood vessels does aorta branch into

Answer 9

aorta, elastin arteries, muscular arteries, arterioles

Question 10

what is the effect of more elastin in tunica media

Answer 10

more distensible - when high bp- elastin arteries

Question 11

what is the effect of more smooth muscle in tunica media

Answer 11

vasoconstriction

Question 12

what is the diameter of aorta, elastin arteries, muscular arteries and arterioles

Answer 12

aorta and elastin arteries- 4 mm!
muscular arteries- 0.3-10 mm
arterioles- 10 UM- 0.3 mm

Question 13

what is the effect of neural/ chemical stimuli on arterioles

Answer 13

change in diameter of arterioles- changes blood flow to capillaries- gas exchange

Question 14

what is the diameter of capillaries

Answer 14

8-10 UM = smallest diameter of all blood vessels

Question 15

what are the two types of capillaries and how are they different

Answer 15

continous= tight junction between endothelial cells. have intercellular clefts

fenestrated= pores in endothelial cells so more permeable. found in SI, kidney.

Question 16

how is blood flow regulated within the capillaries

Answer 16

smooth muscle sphincter

when smooth muscle sphincter contracts= blood flows

Question 17

what is the meta- arteriole

Answer 17

big blood vessel lying over the capillary bed

Question 18

what is the diameter of venules

Answer 18

8-100 UM

Question 19

what is the organisation of venules

Answer 19

largest will have 3 layers

smallest will only have endothelium layer

Question 20

at any given time, which vessel is 65% of all blood volume

Answer 20

veins- here the bp is also lowest

Question 21

which vessel is the biggest resistance to flow

Answer 21

arterioles- smooth muscle= vasoconstriction= reduces bp

Question 22

what controls the blood pressure of the venous return

Answer 22

respiratory pump
skeletal muscle pump
venous valves

Question 23

what does the respiratory pump do

Answer 23

causes inspiration

• increases abdominal pressure
• also, reduces thoracic pressure, thoracic veins dilate, more blood to R. atrium

Question 24

what does the skeletal muscle pump do

Answer 24

causes skeletal muscle (legs) to contract, compresses the deep veins between them, propels blood to heart