Exam 1 - Lecture 1 Flashcards
renal clearance of stuff from kidney is
volume of plasma cleared over time
CH2O is what?
Clearance of free water or free water clearance, which is volume of water cleared from body per unit of time.
Our free water clearance is _____ when we have alot of ADH
low
Our free water clearance is ____ when we have few ADH
high
How do we calculate the MAP?
Diastolic pressure PLUS 1/3rd of the difference between systolic and diastolic pressure.
e.g.: 80 + ((120 - 80)/3) = 93
Highest resistance blood vessels in circulation are
arterioles
Upstream of arterioles, pressure is _____. Downstream, pressure is
High; low
The blood pressure in the venules is
10 mmHg
What is the pressure in the right atrium
0 mmHg, when healthy. If they are sick, it’ll be higher.
Delta P of systemic circulation is what?
100 mmHg.
100 at the aorta, 0 at the end (right atrium)
Pulmonary arterial pressure MAP is
16 mmHg
What is the MAP referred to in pulmonary artery?
PAP, or mPAP (mean)
Normal systolic and diastolic pressure in pulmonary artery is
25/8
What is the end of the pulmonary circuit?
Left atrium
Pressure of the left atrium
2 mmHg
Delta P of entire pulmonary circuit is
16 - 2 = 14 mmHg
(16 in the PA, 2 in the left atrium.)
PP means
pulse pressure
What is pulse pressure
difference between systolic and diastolic pressure
120/80 = PP of 40
Where is pulse pressure highest?
Large arteries
Why is there a widening of the pulse pressure in the large arteries compared to the aorta?
the walls are more stiff, whereas the aorta is more stretchy.
If the walls are stiff, there will be a _____ pulse pressure. If they are stretchy, there will be a _____ pulse pressure.
Higher; lower
If a vessel wall had zero stretch to it, what does this do during systole and diastole?
systole would be extremely high, diastole would be extremely low. Walls do not move, it is completely dependent upon the blood flow.
Are the veins stretchy or stiff?
Very stretchy, thats why pressure doesnt really change in the veins.
What are two things that can increase pulse pressure?
Higher stroke volume, and higher wall resistance.
What is the reason for low pressure in pulmonary circuit?
low resistance!!!
What is the term to describe stretchiness?
compliance
Compliance is
change in volume over change of pressure (Delta V/ Delta P)
If it requires a ton of pressure, to put in a volume container, compliance is
low
If it requires little pressure to put in a volume container, compliance is
high
left ventricle delta p is
120
(120 - 0)
The right ventricle will have what kind of pressure in comparison to the right ventricle?
they will be the same during peak systole and 0 during diastole
The smooth muscle in veins is what compared to arteries?
much thinner and not as much.
What lines up the inside of the entire vascular system?
endothelial layers.
Continous all the way through the circulation system including the chambers of the heart.
A healthy aorta will be ____ and how does it change as we age?
stretchy, starts to stiffen.
Normal cardiac output is
5L/min
Normal heart rate is
72bpm
Normal stroke volume
70cc
What does V = F/A mean?
Velocity = Flow divided by area
How much distance of gravity of blood is 1 mmHg?
13.6 mm
The further below the pressure source (heart), gravity will make the pressure ____
heavier
What is the isogravimetric point? where is it?
point where gravity has zero effect on the pressure, which is located at the tricupside valve.
How much pressure in the vein at the belly button is solely due to gravity?
22 mmHg
How much pressure in the vein at the knee is solely due to gravity?
40 mmHg
How much pressure in the vein in the foot is solely due to gravity?
90 mmHg
How much pressure in the upper arm in the vein due to gravity?
6-8mmHg, even tho its even with the heart, its due to the curvature of the blood going up into the shoulder then down.
What is the pressure in the veins of the neck? why?
- if it was negative, they would collapse because theyre thin walled and very compliant.
What is the pressure in the sagittal sinus?
-10mmHg, stiff with meninges in the walls that keep it open regardless of negative pressure.
How do we combat gravity in the veins?
1-way valves.
The valves act as shelves, once it passes it cant go back down.
What helps move blood out of our legs back to heart?
moving around, skeletal muscle contracting and relaxing.
The valves are _____ than the veinous wall
even thinner
Not meant to support large loads
As you age, the valves in the leg will ?
the valves stop closing and it leads to build up of venous blood in the legs
Do arteries have one way valves?
no
Distensibility
Increase in volume / (increase in pressure x original volume)
Vascular compliance
Increase in volume / increase in pressure
Another word for distensibility is
expandability
Conductance = ?
1 / resistance
conductance is the inverse of resistance!
Conductance is equal to diamater …?
to the 4th power
Very little change in diameter will increase conductance.
CV version of V = IR?
What can V be expressed as?
V = Blood pressure
I = Blood flow
R = Vascular resistance
V can be expressed as Delta-P.. so 100 mmHg
Solve for Vascular resistance.. I = 5L/min, and V = 100
100mmHg / 5L per min… gives you SVR.
Per the chart, what happens to the pressure when you add a little bit of volume to arteries? Veins?
Which system is more compliant?
goes way up! doesnt take much.
hardly moves for veins…
Veins!
An increase in CVP will result in an increase in?
Right atrial pressure
