Vascular Structure and Function in Hypertension

Question 1

what is the function of penyephrine?

Answer 1

-alpha 1 adrenergic powerful vasoconstrictor
-can constrict blood vessels in the nose to help with breathing
-alpha 1 antagonist used to be used to treat hypertension but not anymore

Question 2

what happens to blood vessels as we age?

Answer 2

blood vessels will not be able to change diameter as much

Question 3

what naturally causes vasodilation?

Answer 3

-release of nitric oxide by endothelial cells usually causes vasodilation of blood vessels

Question 4

how does systolic BP change with age?

Answer 4

increases

Question 5

what effect does oestrogen have on vessels?

Answer 5

powerful vasodilator

Question 6

what does oestrogen administation do?

Answer 6

promotes vasodilation in humans and in experimental animals by stimulating prostacyclin and nitric oxide synthesis as well as decreasing the production of vasoconstrictor agents such as cyclooxyrgenase derived products, reactive oxygen species, angiotensin II and endothelin-1

Question 7

what is the normal vascular structure (outer to inner)?

Answer 7

-perivascular adipose tissue
-tunica adventitia
-tunica media
-internal lamina
-tunica intima

Question 8

what is the tunica adventitia?

Answer 8

nerves, external lamina, adventitial, fibroblasts, elastin, collagen, immune cells

Question 9

what is the tunica media?

Answer 9

smooth muscle cells

Question 10

what is the internal lamina?

Answer 10

between tunica media and intima
contains small holes which allow endothelial cells in tunica intima below, to communicate with smooth muscle cells in the tummy media

Question 11

what is the tunica intima?

Answer 11

endothelial cells

Question 12

how are smooth muscle cells arranged in vessels?

Answer 12

arranged helically like springs in the blood vessels

Question 13

why is the function of smooth muscle cell structure?

Answer 13

blood pressure passing in these resistance vessels is dampened by these spring like smooth muscles

Question 14

what is pulse wave velocity?

Answer 14

measurement of the effectiveness of dampening

Question 15

what does high pulse wave velocity mean?

Answer 15

more recoiling which means blood pressure is not dampened by the springs due to stiffness of vessels

Question 16

what does hypertension cause in blood vessels?

Answer 16

blood vessel remodelling
increased tunica media - lumen ration
thicker tunica media, narrower lumen

Question 17

what are the effects of rats hindlimb unloading on their basilar artery (similar to being space)?

Answer 17

-if back legs raised, less blood will travel to them and instead the blood will go back to the brain
not good as brain requires constant blood supply
-basilar artery which goes to the post brain, remodels. the tunica media thickens and lumen narrows to keep blood flow to the brain constant

Question 18

how does length affect flow?

Answer 18

flow is linearly proportional to length
doubling length doubles the time taken to pass through

Question 19

how does radius affect flow?

Answer 19

small changes in radius have profound changes in flow
doubling radius causes time taken to pass through increase by 16 times

Question 19

what is hypotrophic remodelling?

Answer 19

wall becomes thinner
lumen can still move inwards/narrow or outwards

Question 20

what is hypertrophic remodelling?

Answer 20

walls become thicker
lumen can still move inwards

Question 21

what is eutrophic remodelling?

Answer 21

material int he walls stays the same but the lumen becomes narrower or wider (happens in hypertension)

Question 22

what happens to tunica intima during hypertension?

Answer 22

holes within the tunica intima will decrease in size

Question 23

What is the most likely vascular remodelling expected in a patient with chronic hypertension?

Answer 23

Thickening of tunica media

Question 24

Which layer of the blood vessel is the smooth muscle layer?

Answer 24

Tunica media