Caridovascular Physiology Flashcards by Em E

Arteries are…

Pressure reservoir that maintain blood flow
Adjustable diameters (alters resistance) to alter blood flow

How well did you know this?

Not at all

Perfectly

Where is gas exchange?

Capillaries

How well did you know this?

Not at all

Perfectly

Systemic Veins are…

Expandable reservoir

How well did you know this?

Not at all

Perfectly

Each side of the heart functions…

independently

How well did you know this?

Not at all

Perfectly

Blood Pressure

Arterial blood pressure
Pressure exerted on walls of the blood vessels
Reflects driving pressure

How well did you know this?

Not at all

Perfectly

Ventricular contraction

Pushes blood into arteries which causes stretch
Systole - contraction
1) Ventricles contract
2) Semi-lunar valve opens. Blood flows into valves
3) Aorta and arteries expand and store pressure in elastic walls

How well did you know this?

Not at all

Perfectly

Ventricular Relaxation

Elastic recoil in arteries maintain pressure during diastole
Diastole - Relaxation
1) isovolumic ventricular relaxation
2) Semilunar valve shuts, preventing flow back
3) Elastic recoil of arteries sends blood forward into rest of the circulatory system

How well did you know this?

Not at all

Perfectly

Why does blood flow work?

Because of pressure gradients
Heart creates high pressure
From the heart (high pressure) to the arteries (low pressure)

How well did you know this?

Not at all

Perfectly

How is blood pressure measured?

Estimated by brachial artery through sphymomonometry
Arterial pressure reflects ventricle and aortic pressure
mmHg

How well did you know this?

Not at all

Perfectly

Process of measuring BP

inflate until arterial blood flow stops (no sound)
Korotkoff sound pulsatile blood flow (systolic pressure)
Blood flow silent (diastolic pressure)

How well did you know this?

Not at all

Perfectly

What is systolic blood pressure?

Highest pressure

occurs during ventricular systole (contraction)

How well did you know this?

Not at all

Perfectly

What is diastolic pressure?

Lowest pressure

occurs during ventricular diastole (relaxation)

How well did you know this?

Not at all

Perfectly

What is Pulse pressure?

Change in systolic and diastolic pressure

How well did you know this?

Not at all

Perfectly

What is mean arterial pressure?

Average pressure of the heart during cardiac cycle

How well did you know this?

Not at all

Perfectly

Formulas

Pulse pressure = Systolic - diastolic

MAP = DBP + 1/3 (SBP-DBP)

How well did you know this?

Not at all

Perfectly

Blood Pressure Classifications

Normal Blood Pressure - 120/80 mmHg (decreased risk of CVD)
Hypotension - when BP is too low
Hypertension - 140/90 mmHg or above (when blood pressure is chronically elevated)

How well did you know this?

Not at all

Perfectly

What Determines Blood Pressure?

Arterial Pressure Balance

MAP increases when in exceeds out

MAP decreases when out exceeds in

What determines BP?

Blood volume distribution

Relative amount of blood in arterial vs venous
Arteries = low pressure 11% of blood volume
Veins = high pressure 60% of blood volume
Arterial pressure falls, veins constrict and decreases capacity increases venous return

What determines BP?

Total blood volume

Blood volume increases blood pressure increases

Blood volume decreases blood pressure decreases

MAP is determined by

Blood volume (fluid intake)
Effectiveness of heart (HR and SV)
Resistance of the system to blood flow (Diameter of arteries)
Relative distribution of blood between arterial and venous blood (diameter of veins)

Blood pressure regulation

Blood pressure includes rapid response from CVS and slower response from kidney

Fast response BP Regulation

Increase blood volume
Increase blood pressure
compensation by cardiovascular system
- Vasodialtion
- decrease Q
Decreased blood pressure

Slower response BP regulation

Increase blood volume
Increase blood pressure
Compensation by the kidney
Excretion of fluid = decreased volume
decreased BP

What are baroreceptors

Stretch sensitive
Located on walls of aorta and carotid arteries
Detect increase in pressure = increased stretch
Increase stretch= increased afferent firing of carotid sinus nerve

Barorecpetors at normal BP

aortic and carotid receptors fire continuously (afferent) | Normal firing rate normal sympathetic activity (Efferent)

Baroreceptors | Change in BP

BP increase = Increase firing rate | BP decrease = Decrease firing rate

Baroreceptors Sympathetic Activity Change in BP

decrease firing rate = increase sympathetic activity | Increase firing rate = decrease sympathetic activity

Baroreceptor Reflex | Parasympathetic

``` Increase BP Increase firing rate Increase parasympathetic Decrease HR Decrease Q Decrease BP ```

Baroreceptor Reflex | Sympathetic

``` Increase BP Increase firing rate Decrease sympathetic In the Artiolar Vasodialtion Decrease TPR Decrease BP ``` In the Ventircular myocardium Decrease force of contraction decreases Q decrease BP In the SA node decrease HR Decrease Q Decrease BP

What happens when there is a Hemorrhage?

``` Arterial Pressure decreases low firing rate low para/up sympathetic up HR up SV up Q ``` Veins constrict/arteries constrict Up venous pressure up TPR Up Venous return Up EDV Increase TPR + Q = Increase arterial pressure

CVD

``` Disorder of the Heart and blood vessels 2007- 1.3million 2008 - 29% of all deaths 2004 3 million hospitalizations Costs $2.9 billion/yr ```

What are non-modifiable risk factors?

``` Age Gender Family History Ethnicity History of stroke or TIA ```

What are modifiable risk factors?

``` High BP Smoking Inactivity Overweight High cholesterol Diabetes Excessive alcohol Stress ```

Blood Pressure and CVD

90% of people with hypertension have primary hypertension Hereditary Increase TPR Baro- receptors adapt to higher pressure Activity decrease no reflex control Increase atherosclerosis (plaque formation) Increase BP increase myocardial work ( Increase after load, SV same = high resistance = myocardial hypertrophy)

Hypertension Drug Treatment

Calcium blockers Target: Cardiac and smooth muscle Effects: less calcium entry Result: HR and contractility decrease and vasodilation Other Diuretics: decrease blood volume Beta-blockers: suppress sympathetic stimulation ACE inhibitors and angiotensin receptor blockers: decrease vasoconstriction by angitotensin

Coronary Artery Disease

``` Majority of all deaths (54%) Atherosclerosis - hardening of arteries - fat deposits on walls - Plaque formation - Inflammatory response ```

Development of Atherosclerosis | Fatty Streak

1) LDL- cholesterol accumulates between the endothelium and connective tissue and is oxidized 2) Macrophages ingest cholesterol and become foam cells (release cytokines) 3) smooth muscle attracted by macrophage cytokines, begins to divide and take up cholesterol

Development of Atherosclerosis | Stable Fibrous plaque

4) Lipid accumulates beneath endothelium 5) Fibrous scar tissue to walls off lipid core 6) Smooth muscle divide and contribute to thickening 7) Calcification within the plaque

Development of Atherosclerosis | Vulnerable plaque

8) macrophages release enzymes that dissolve collagen and make plaque unstable 9) Platelets at exposed to collagen activate and clot

What is ejection fraction?

SV/EDV