Hypertension I: Cowley

Question 1

Four ways to increase Arterial Pressure

Answer 1

• Constricting most arterioles of the body–> increases total peripheral resistance.
• Increasing blood volume –> increases
venous return and CO
• Constricting large vessels of the circulation,
–> increases venous return and CO
• Directly increasing CO by increasing HR and contractility.

Question 2

Constricting most arterioles of the body–> increases

Answer 2

total peripheral resistance.

Question 3

• Increasing blood volume –> increases

Answer 3

venous return and CO

Question 4

• Constricting large vessels of the circulation

–> increases

Answer 4

venous return and CO

Question 5

We can directly increase CO by increasing

Answer 5

HR and contractility.

Question 6

In short term BP regulation, vasodialators can decreased vascular tone which will decrease _________ which then lowers BP

Answer 6

Peripheral resisitance

Question 7

What to receptors when activated will increase vascular tone?

Answer 7

alpha 1 and AT1

Question 8

What Neural controls will act on vascular smooth muscle?

Answer 8

Vasoconstictors; SNS nerves

Vasodialators: Neurons releasing NO

Question 9

What local controls act on the arterial smooth muscle?

Answer 9

Vasocnx; myogenic response

Vasodialtors: PO2 reduction/K+,CO2/H+, osmolality, NO, adenosine (based on metabolizm)

Question 10

What Humoral controls will act on arterial smooth muscles?

Answer 10

Vasocnx: Nepi, Ang II, Vasopressin, endothelin, thrombaxanes
VasoD: Epi, ANP, Bradykinin, Histamine, PGEs

Question 11

How is Ca++ concentration in vascular smooth muscle modulated?

Answer 11

via signal transduction mechanisms; NE/AII, ET-1 will bind to their GCPR which activates PLC–>make IP3 and DAG–> get IP3 going to SR to release a bunch of Ca++

Question 12

How does nervous regulation affect circulation?

Answer 12

1. Redistribution of blood flow to different areas.
2. Affects HR and pumping activity of the heart.
3. Essential for the very rapid control of arterial pressure.

Question 13

Reticular substance has a key role in circulation

• lateral and superior portions ~
• medial and inferior portions ~

Answer 13

• lateral and superior portions ~ excitation

- medial and inferior portions ~ inhibition

Question 14

Hypothalamus has key roles in circulation regulation:

• posterior-lateral portions cause mainly
• anterior portion can cause

Answer 14

excitation

mild excitation or inhibition.

Question 15

Motor cortex has key roles in circualtion regulation:

Answer 15

• excitation or inhibition depending on region stimulated

Question 16

Located bilaterally in the reticular substance of

the medulla and lower third of the pons.

Answer 16

Vasomotor center

Question 17

Vasoconstrictor area “C-1” located in:

role is:

Answer 17

anterolateral upper medulla

sympathetic discharge

Question 18

What area inhibits C-1 area (C1 key for sympathetic discharge)

Answer 18

Vasodilator area “A-1” anterolateral lower medulla:

Question 19

Sensory area “A-2” bilateral in :

what is it’s role:

Answer 19

nucleus tractus solitarii

receive sensory signals from vagus and glossopharyngeal from baroreceptors. Control C-1 and A-1 areas.

Question 20

Control C-1 and A-1 areas.

Answer 20

Sensory A2 bilateral in nucleus tractus solitarii

Question 21

Sympathetic nerve fibers innervate all vessels except

Answer 21

capillaries and precapillary sphincters and some meta arterioles.

Question 22

Innervation of small arteries and arterioles allow sympathetic nerves to

Answer 22

increase vascular resistance.

Question 23

Large veins and the heart are also_______ innervated.

Answer 23

sympathetically

Question 24

• Parasympathetic nervous system is mainly important in control of

Answer 24

heart rate via the vagus nerve.

Question 25

Effect of total spinal anesthesia on the arterial pressure | Sympathetics responsible for

Answer 25

“vasomotor tone” *when you remove SNS, arterial pressure drops ( you can increase it with Nepi injection, but will go back down once that wears off (baseline is around 100)

Question 26

In vascular smooth muscle, alpha 1 R, when bound by Nepi from the Sympathetic neuron, causes

Answer 26

vasocontriction

Question 27

What is the role of the alpha 2 adrenergic receptor?

Answer 27

It's located on the sympathetic neuron that releases the Nepi... when bound, will inhibit Nepi release via negative feedback

Question 28

alpha 1 is located on in the ______ while Beta 2 is located on the ______; both bind Nepi from the SNS

Answer 28

``` vascular smooth muscle (vasocnx) myocardium muscle (increase HR and contractility) ```

Question 29

What happens when a B2 receptor is bound by Nepi in the myocardium

Answer 29

increase in HR and contractility

Question 30

• Baroreceptors are spray type nerve | endings located in what two places?

Answer 30

walls of the carotid bifurcation= the carotid | sinus and in the walls of the aortic arch.

Question 31

Signals from the carotid sinus are | transmitted by the Hering’s nerve to the _________nerves and then to the ______of the medulla

Answer 31

glossopharyngeal | NTS

Question 32

How are signals from the arch of the aorta transmistted into the NTS?

Answer 32

through the vagus

Question 33

Baroreceptor pressure control system is based on a

Answer 33

negative feedback control system

Question 34

Feeback gain represents the:

Answer 34

strength of the feedback

Question 35

what is the equation for feedback gain?

Answer 35

G = correction of error signal/ Error (abnormality still remaining)

Question 36

Arterial pressure is sitting happy at 100mmHg... if you clamp the carotids you will decrease the pressure at teh carotid sinuses... this results in:

Answer 36

increased arterial pressure. once the clamps are released, you go back to normal

Question 37

Which will cause more firing of the carotid sinus nerve: an arterial pressure of 50 or an arterial pressure of 200?

Answer 37

Arterial pressure of 200 results in much more firing of the carotid sinus nerve... higher the Pa... the more the firing

Question 38

Carotid sinus baroreceptors respond to pressures between

Answer 38

60 and 180 mmHg.

Question 39

Baroreceptors respond to______ in arterial pressure. | • Baroreceptor reflex is most sensitive at a pressure of ______

Answer 39

CHANGES | 100mmHg

Question 40

As pressure increases the number of impulses from carotid sinus increases which results in: 1) inhibition of the_______ 2) activation of the _________

Answer 40

vasoconstrictor | vagal center

Question 41

When carotid distending pressure is low (around 50-70 mmHg) you will have high or low firing of SNS nerves?

Answer 41

very HIGH firing

Question 42

When carotid distending pressure is higher (around 125 to 200 mmHg) you will have high or low firing of SNS nerves?

Answer 42

very LOW firing

Question 43

When carotid distending pressure is low (around 50-70 mmHg) what happens to the R-R interval?

Answer 43

you have a lower rate, or shorter R-R interval (at this time the SNS firing is HIGH)

Question 44

When carotid distending pressure is higher (around 125 to 200 mmHg) what happens to the R-R interval?

Answer 44

you have a higher rate, or increased R-R interval (at this time the SNS firing is LOW)

Question 45

In the experiment when we denervated the dog's baroreceptors, what happened to the arterial pressure? How did the average of arterial pressure over a day change?

Answer 45

From second to second the dog couldn't normalize the Pa... it went up and down... but over the course of a day, it averages out to normal.

Question 46

“Resetting” of baroreceptor has been thought to prevent | the_______ from functioning as a control system for changes in pressure that last more than a day.

Answer 46

reflex | recent data shows that this resetting may not be complete

Question 47

angiotensinogen --> Ang I via

Answer 47

renin, from the kidney, splits btwn Leu-Val

Question 48

Ang I--> AngII via

Answer 48

ACE in lung splits between Phe-His | --ACE is vasoactive and works to increase smooth musl contraction

Question 49

Once Ang II has been made, it will act on AT1 and causes:

Answer 49

vasocnx, fibrotic rxn, inflmammation and antinaturietic activation

Question 50

ACE converts Ang I --> Ang II which causes: | ACE converts Bradykinin to its active or inactive form?

Answer 50

causes vasocnx and aldosterone release = Na+ retention | Bradykinin to INactive form; no more NO release or vasodilation

Question 51

Shit below happens as result of HTN NO--> ONOO- causes: O2-->O2- and then H2o2 cause:

Answer 51

endothelial dysfunction | medial wall hypertrophy

Question 52

Bad "ROS" as a result of HTN

Answer 52

increased GSSG/H2O2/O2- lipid peroxidation increased Ang II and aldosterone --Affects most systems in the body, we get remodeling, fiborsis, vasocnx, ex

Question 53

Essential HTN affects 26% of world population, 67 million americans and is only controlled in _____ of US population

Answer 53

1/2

Question 54

What age and ethnicity is mostly affected by HTN

Answer 54

60 and over and african americans | is found younger and in other races

Question 55

How is HTN defined?

Answer 55

by mortality risks as RATIOS of actual to expected deaths from cardiovascular and renal disease among insured individuals

Question 56

Classification for Normal BP Pre-HTN HTN

Answer 56

normal <80 diastolic pre-HTN 120-139 and 80-89 for systolic HTN 140-159 and 90-99 for systolic anything higher is higher stage of HTN

Question 57

The operational definition of hypertension is:

Answer 57

level at which the benefits of action exceed those of inaction

Question 58

There is no dividing line (between normal and high BP). | The relationship between arterial pressure and mortality is quantitative;

Answer 58

the higher the pressure, the worse the prognosis

Question 59

Difference between Platt and Pickering's hypothesis

Answer 59

Platt said there are 2 groups of individuals with different distributions of BPs Pickering said it was a continous curve, which is the case

Question 60

Measure blood pressure twice and take the average because:

Answer 60

The running average is more important than individual readings.

Question 61

Hypertension is diagnosed if the average of at least_____readings per visit obtained at ____ separate visits each _____to ___weeks apart is 140 mm Hg or greater systolic and 90 mm Hg or greater diastolic.

Answer 61

2 readings per visit 3 seperate visits 2 to 4

Question 62

Hypertenion is diagnosed when systolic is greater then ____ and diastolic is greater then _____

Answer 62

140 | 90

Question 63

Systolic and Diastolic pressure increase as we get older, what age do we start to see a greater rise and which is more affected, systolic or diastolic?

Answer 63

see more increase around 40-50 and systolic is more affected then diastolic

Question 64

What two factors would increase your risk for IHD?

Answer 64

raise in systolic or diastolic BP risk increases as you age if you have high BP and you are older, even more risk