CV System and Disorders- Week 4 Set 2 Flashcards
Negative feedback systems incorporating pressure sensors that sense the arterial pressure
Baroceptors
The most important arterial baroreceptors
carotid sinus and in the aortic arch
Mechanism of Baroceptors
- stretching of the arterial wall (d/t increase pressure) 2. walls expand
- increases firing of AP generated by the receptors.
- If pressure decreased stretch of walls leads to a decrease in AP firing
Sensors that detect changes in CO2, O2, and pH
Chemoreceptors
What types of Chemoreceptors are there?
arterial and central
Chemoreceptors that monitor changes in partial pressure of O2 and CO2
Arterial
Principal peripheral chemoreceptors
Carotid bodies
Carotid bodies detect changes in arterial blood oxygen levels, and the resulting chemoreflex is…
regulation of blood pressure.
What happens to chemoreceptors exposed to chronic hypoxia or increased CO2?
They can be desensitized
When there is no identifiable cause of high blood pressure.
Primary (essential) hypertension
High blood pressure caused by an underlying condition
Secondary hypertension
Characteristics of secondary hypertension
Tends to appear suddenly and cause higher BP than primary
Characteristics of primary hypertension
Tends to develop gradually over many years.
Pulse pressure
difference between the systolic and diastolic blood pressures
average pressure in a patient’s arteries during one cardiac cycle
Mean Arterial Pressure
Is systolic BP or MAP considered a better indicator of perfusion to vital organs?
MAP
How is MAP measured
directly by invasive monitoring
Physiological factors that influence your BP
- Cardiac output
2. Peripheral vascular resistance
Physical factors that influence your BP
- Blood volume
2. Elastic property of blood vessels
Does a loss of water volume cause BP to increase or decrease?
Decrease
How does the body react to decrease in BP (or decrease in osmolarity)?
Reacts with different homeostatic mechanisms to try to
increase water volume back to normal levels , restore BP & ensure adequate circulation
The measure of how strongly blood pushes against the walls of arteries,
Blood pressure
What is a string indicator for blood pressure
blood volume, which is related to water volume
If BP gets too low because of inadequate volume what happens?
Vital nutrients won’t get delivered where needed & waste won’t be taken away.
baroreceptors that monitor BP & flow in kidney
Juxtaglomerular Apparatus
If decreased, JGA produces & releases what hormone
Renin
When Renin is released by the JGA what happens?
- Activates RAAS
- vasoconstriction
- increased Na+ & water resorption in kidneys
- restored water volume
Measure of how many osmotically active solute particles there are in a unit volume of water
Osmolarity
What is measured in blood osmolarity to determine osmolarity for a blood cell?
Na+
If the blood osmolarity is higher than normal, the body’s osmoreceptors think what is happening?
That there’s been a loss of volume.
How does the body react to the body’s osmoreceptors thinking that there’s been a loss of volume?
- Releasing Vasopressin [Anti-Diuretic Hormone (ADH)] via hypothalamus to activate a chain of events that leads to increased water resorption by kidneys.
- The brain induces feelings of thirst so one will
Tumor on adrenal glands (top of kidneys)that can cause renal failure
Pheochromocytoma
What condition can a. Sleep apnea can lead to?
HTN
JNC 7/8 emphasizes the importance of what?
Low BP
JNC: Normal
<120 and <80
JNC: Prehypertension
120-139 OR 80-89
JNC: Stage 1
140-159 OR 90-99
JNC: Stage 2
> 160 OR > 100
Goal of treating HTN
Prevent target organ damage
What organs are effects by HTN?
Brain
Heart
Kidneys
How does HTN effect: Brain
Stroke
How does HTN effect: Kidneys
Renal failure
Top two reasons for renal failure
Diabetes
HTN
Mean Arterial BP calculation
CO X SVR (cardiac output)x(systemic vascular resistance)
Factors influencing Mean Arterial BP: Physical
- Volume
2. Elastic Properties
Factors influencing Mean Arterial BP: Physiologic
- CO
2. Vascular resistance
Examples of things that cause primary hypertension
Lifestyle related: Alcohol, smoking, obesity. poor diet
Extremely high blood pressure that develops rapidly and causes some type of organ damage
Malignant hypertension
Malignant hypertension how high?
above 180/120
How to remember Systolic vs Diastolic HTN?
SC-Systole contraction
DR- Diastole relaxation
Are genetics a risk factor for HTN?
Yes
High blood pressure that develops after 20 weeks of pregnancy
gestational hypertension
Some women with gestational hypertension can eventually develop…
Preeclampsia
If not treated properly gestational hypertension can also lead to fetal problems including…
intrauterine growth restriction (poor fetal growth) and stillbirth
Lesion formation by the promotion of both the early and late mechanisms of atherosclerosis
Endothelial dysfunction
Family of organic compounds that are mostly insoluble in water, composed of fats and oils, yield high energy
lipids
Primary functions of lipids
- Structure of cell membranes
- Energy storehouses
- Signaling molecules
Three main types of lipids
- triacylglycerols (also called triglycerides)
- phospholipids
- sterols (cholesterol)
Hypercholesterolemia vs HLD
Hyperlipidemia means your blood has too many lipids (or fats), such as cholesterol and triglycerides.
hypercholesterolemia is a type of HDL and means there’s too much LDL cholesterol in your blood.
Substances made of protein and fat that carry cholesterol through your bloodstream
Lipoproteins
Types of lipoproteins
HDL
LDL
VLDL
Chylomicrons
Good cholesterol
HDL
Bad cholesterol
LDL
Total cholesterol levels in relation to heart disease risk
Low <200
Borderline 200-239
High 240+
LDL cholesterol levels in relation to heart disease risk
Low <130
Borderline 130-159
High 160+
HDL cholesterol levels in relation to heart disease risk
Low >60
Borderline 50-59
High <50
Triglycerides levels in relation to heart disease risk
Low <150
Borderline 150-199
High >200
Is HLD genetically linked?
Very
If HLD is in family what should occur?
Children should have lipid checked
More of HDL causes what?
good, more of these less risk for CAD
Why do we need them?:
- Energy metabolism
- Blood coagulation
- For myelin sheath in brain and some membranes
Which lipoprotein is not monitored much?
VLDL