L27 Pathophysiology and Treatment of Hypertension

Question 1

what ensures fluid balance within the body?

Answer 1

cardiovascular and renal system

Question 2

what causes hypertension?

Answer 2

high blood pressure

Question 3

what is a determinant in blood pressure and haemodynamics?

Answer 3

resistance to blood flow

Question 4

where is there high resistance to blood flow?

Answer 4

in small vessels like capillaries

Question 5

what vessel is the most resistant to blood flow?

Answer 5

arterioles

Question 6

what is systolic pressure?

Answer 6

the highest blood pressure when ventricles are contracting

Question 7

what is diastolic pressure?

Answer 7

the lowest blood pressure in cardiac cycle when ventricles are relaxing

Question 8

why does pressure not reach 0 in arteries?

Answer 8

because they have thick elastic walls and ability to recoil

Question 9

explain pressure through circulatory system from highest to lowest in reference to areas

Answer 9

arterioles, arteries, capillaries, venules, veins

Question 10

what is blood flow equal to?

Answer 10

pressure gradient/ resistance

Question 11

what is the resistance of flow proportionate to?

Answer 11

length of tube x viscosity/radius

Question 12

what explains the factors that cause resistance to flow?

Answer 12

Poiseulle’s Law

Question 13

what factors cause resistance to blood flow?

Answer 13

vasodialation and vasoconstriction

Question 14

what is the ‘rest state’?

Answer 14

partial contraction - allows restriction or dialation

Question 15

what determines blood flow?

Answer 15

blood pressure and degree of vasconstriction and vasdialation

Question 16

what induces vasodilation and reduced blood pressure? (increased blood flow)

Answer 16

nitric oxide and endothelin from endothelial cells

Question 17

what hormone causes vasodialation?

Answer 17

histamine

Question 18

what hormone causes vasoconstriction?

Answer 18

ADH

Question 19

what metabolistic features cause dialation?

Answer 19

decreased oxygen availability and temperature increase

Question 20

what metabolistic feature causes constriction?

Answer 20

nervousness/ anxiousness

Question 21

what gives a false blood pressure reading?

Answer 21

arm raised above heart due to gravity interference

Question 22

what is ideal blood pressure?

Answer 22

120mmHg at systole and 70mmHg at diastole

Question 23

what is venous return?

Answer 23

the return of blood - flowing the wrong way

Question 24

what is Total Peripheral Restriction (TPR)?

Answer 24

The sum of vasodialation and vasconstriction in an entire system

Question 25

what determines mean arterial pressure/ blood pressure?

Answer 25

heart rate, stroke volume and TPR (sum of dialation and constriction)

Question 26

what is involved in short term regulation of BP?

Answer 26

baroreceptor reflex

Question 27

what is involved in long term regulation of BP?

Answer 27

regulation of blood vol via kidney, hormonal control

Question 28

how is blood pressure decreased?

Answer 28

1) mechanoreceptors: baroreceptors of aortic arch and carotid sinus activate 2) nerve endings respond to stretch of vessel wall 3) dialation of blood vessel

Question 29

what nerves connect to baroreceptors that allow change of BP?

Answer 29

A and C fibres

Question 30

what are A fibres?

Answer 30

myelinated, detect low pressures of around 30.90mmHg

Question 31

what are C fibres?

Answer 31

unmyleniated, detect high pressure of 70-140mmHg

Question 32

what happens in relation to autonomic system when lowering blood pressure?

Answer 32

promote parasympathetic stimulation and lower sympathetic stimulation

Question 33

what do baroreceptors do?

Answer 33

they detect the pressure and input into CNS medulla which activates either the parasympathetic or sympathetic nervous system

Question 34

what does the renin-angiotensin aldotesterone system do?

Answer 34

it regulates sodium and water balance

Question 35

how does renin-angiotensin aldosterone system influence blood pressure?

Answer 35

1) when blood pressure drops this pathway occurs via secretion of renin in kidneys 2) angiotensinogen proteins cleaved by renin to form angiotensin 1 3) angiotensin 1 forms angiotensin 2 when flowing through lungs 4) it produces aldosterone in kidneys to increase sodium reabsorption (conserves water)

Question 36

what does angiotensin 2 stimulate?

Answer 36

thirst response and secretion of ADH (which increases water reabsorption)

Question 37

what happens renal arteries during hypertension?

Answer 37

left and right arteries narrow

Question 38

how is angiotension1 converted to angiotensin 2?

Answer 38

ace enzyme

Question 39

how do we diagnose hypertension?

Answer 39

systolic pressure above 140 and diastolic pressure below 90

Question 40

how to treat hypertension

Answer 40

decrease in alcohol, dietary, exercise, thiazide diuretics, ace inhibitors (inhibit alderstone formation)

Question 41

what happens when renal arteries narrow?

Answer 41

less blood flow - kidney thinks this is low blood pressure but it is not which leads to secretion of aldersterone which increases blood pressure by reabsorption of salts

Question 42

what does aldosterone corticoid do?

Answer 42

increases sodium reabsorption which increases blood pressure

Question 43

what relieves hypertension in renal arteries?

Answer 43

stents