Upgrade to remove ads
Only $2.99/month

PATHO exam 1 (Perfusion & Hypertension)

Terms in this set (20)

What do our cells need to survive? How are these things delivered to the cells?
Our cells need nutrients and oxygen to survive; these are delivered by blood.
What factors play a role in central perfusion?
• Generated by cardiac output ( amount of blood pumped by the heart each minute.) Think of major organs and or the whole body.
• Coordinated electrical & mechanical factors move blood through the heart into the vascular system.
• Propels blood to all organs & tissues through arteries & capillaries-- returns the blood to the heart through the veins.
What are the four determinants of cardiac output?
Describe how each functions
• Preload: fluid priming the pump
• Afterload: Peripheral resistance
• Contractility: Starlings law- increasing the stretch of the heart will increase the contraction up to a point

Heart Rate: First responder. Many factors ( dehydration, heart failure etc.) will cause an elevation in heart rate.
Where does tissue perfusion occur? How does the O2 get from the blood into the cell?
• Capillary level- volume of blood flows through to target tissues at the capillary level.

Capillary hydrostatic pressure- pushes plasma through capillaries into interstitial spaces to allow for O2, fluid, and nutrient delivery to the cells.
When we have impairments to our central perfusion, where do we see the effects? What are examples of this?
• Reduction of cardiac output from the heart- Blood loss, decreased supply to the heart (CAD), dysrhythmias.
• Systemic vasodilation

Systemic vasoconstriction.
What are causes of poor tissue perfusion?
• Poor central profusion
• Mechanical Impairment:
○ Blocked blood vessel leading to or from the tissue

Excessive edema within tissue interfering with cellular O2 exchange
Why are middle-aged adults at risk for poor perfusion? Older adults? Children? Infants?
...
What are modifiable risk factors - and what problems do they pose to perfusion?
• Smoking- nicotine vasoconstricts
• Elevated serum lipids- atherosclerosis
• Sedentary lifestyle- obesity
• Obesity- DMT2 and atherosclerosis
• Diabetes Mellitus- Increases risk of atherosclerosis
Hypertension- Increases the work of the heart.
How does the heart get perfused with blood?

What happens when this perfusion is blocked? Think of symptoms and think of ways that the body compensates.
...
When CAD and blockages occur what population of people are at an additional risk and why?
...
What defines hypertension? What is thought to cause it?
• Consistent elevation of systemic arterial blood pressure
• Combination of genetic and environmental factors thought to be responsible for development. ( Heridity, modifiable risk factors).
• Results from:
○ Sustained increase in peripheral resistance ( arterial vasoconstriction known as afterload)
○ Increase in circulating blood volume ( increased preload)

Or both
There are two factors that will result in hypertension? (you can have one or both)
○ Sustained increase in peripheral resistance ( arterial vasoconstriction known as afterload)
○ Increase in circulating blood volume ( increased preload)

Or both
Where is the pressure highest in the vasculature?
...
How does insulin resistance contribute to vasoconstriction?
Insulin is In these individuals, glucose levels are not elevated, but their high insulin levels cause other things to go wrong. Excess insulin is associated with increased body fat and obesity. It upsets the normal metabolism of fats, raising cholesterol and triglyceride levels

Insulin is also vasoconstrictor
How does the function of the Renin-Angiotensin-Aldosterone System contribute to vasoconstriction and water retention?
Renin converts angiotensinogen, which is produced in the liver, to the hormone angiotensin I. An enzyme known as ACE or angiotensin-converting enzyme found in the lungs metabolizes angiotensin I into angiotensin II. Angiotensin II causes blood vessels to constrict and blood pressure to increase
When does the kidney release renin? What does renin do to angiotensinogen?
he renin-angiotensin system or RAS regulates blood pressure and fluid balance in the body. When blood volume or sodium levels in the body are low, or blood potassium is high, cells in the kidney release the enzyme, renin. Renin converts angiotensinogen, which is produced in the liver, to the hormone angiotensin I. An enzyme known as ACE or angiotensin-converting enzyme found in the lungs metabolizes angiotensin I into angiotensin II. Angiotensin II causes blood vessels to constrict and blood pressure to increase. Angiotensin II stimulates the release of the hormone aldosterone in the adrenal glands, which causes the renal tubules to retain sodium and water and excrete potassium. Together, angiotensin II and aldosterone work to raise blood volume, blood pressure and sodium levels in the blood to restore the balance of sodium, potassium, and fluids. If the renin-angiotensin system becomes overactive, consistently high blood pressure results
What is needed to convert angiotensin I into angiotensin II?
Angiotensinogen converting enzyme
What activities does Angiotensin II initiate? And what does that result in?
...
What is the difference between primary and secondary hypertension?
Primary (essential):
○ No identifiable cause
○ Chronic, progressive disorder
○ Risk:
• Older people> Younger
• African Americans> Caucasian Americans
• Postmenopausal women>premenopausal women
• Not curable but treatable

Secondary:
○ Identifiable cause
○ May treat cause directly
○ Some people can be cured
○ Example:
Tumor that secretes hormone that increases BP and HR-- can be removed-- or a medication that causes retention of Na and H2O can be changed.
What are the consequences of untreated hypertension?
○ Heart disease
○ Kidney disease
○ Stroke
Among Americans with the disease:
○ Only 74% undergo treatment
Only 48% take sufficient medicine to bring their BP under control.
THIS SET IS OFTEN IN FOLDERS WITH...