Lecture 2 Flashcards
The vascular system and hypertension (small arteries focused)
What does capacitance mean?
This is the place where blood is stored (the veins)
Why is the blood pressure difference between systole and diastole lost?
Because the vessels have a lower elasticity the further you go to the small vessels
Why does drawing blood from the veins not cause a big change in pressure?
Because the blood that is there is also partially stored
The blood pressure at the heart is 0, but how does that change through the body and why?
Due to gravity. It is higher when you go lower in than body. And the blood pressure drops even lower when you go higher in the body
What happens to the blood and fluids when there is no gravity?
The blood and fluid pools around the chest/heart/head area
What is the blood pressure in most mammals?
around 120
Is hypertension a disease?
No, it is more of a risk factor
What is the systolic or diastolic pressure in stage 1 hypertension?
Systolic: 130-139
Diastolic: 80-89
What is the systolic or diastolic pressure in stage 2 hypertension?
Systolic: over 140
Diastolic: over 90
What is the systolic or diastolic pressure in stage 3 hypertension?
Systolic: over 180
Diastolic: over 120
With which conditions do you have a higher risk of myocardial infarction?
When you have a stroke, kidney disease, cognitive decline during aging. But it can also be part of a metabolic syndrome
What is the definition of essential hypertension?
There is not one specific thing that can be appointed to the hypertension
What is the definition of secondary hypertension?
It is caused by one specific thing eg a tumor (high cortisol)
Which organs can contribute to hypertension?
Heart, brain, pituitary glans (vasopressin), adrenal and kidney, vessels
What is the formula for pressure
Pressure = blood flow (F) times the resistance (R)
Where is the resistance the highest?
In the small vessels, this is thus also where the pressure is lost
What is the difference between arteries and veins?
Arteries pulsate and are smaller than veins
Is the vascular diameter constant?
No, this means that the resistance is also not constant
How is the balance between dilation and constriction regulated?
By neural, humoral and local hormone, also tissue metabolites, myogenic and endothelial factors
What happens with the constriction in hypertension?
There is more constriction
What are characteristics of functional constriction?
It is a smooth muscle contraction caused by endothelial dysfunction and it can be reversed
What are characteristics of a remodelling constriction?
It is structural and caused by the extracellular matrix, it is irreversible
What are the 5 ways to treat hypertension?
Inhibit the renin-angiotensin system (dilate)
Block calcium channels (dilate)
Diuretics, to pee a lot to lower the volume
Beta blocker, to lower the cardiac output
Life style changes such as lower weight, alcohol and more exercise
What is midlife hypertension and what risk does it increase?
Hypertension that occurs at the ages of 40-59. It increases the risk of dementia
