Lecture 2 Final Flashcards
The movement of fluid out of the capillary is called
Filtration
The process of fluid being absorbed by the capillaries
Reabsorption
What would our pressure look like if we checked it close to the output source (heart) and upstream of the vascular resistance?
It would be an increase in pressure
What would our BP look like if we measures downstream of the vascular resistance (veins)?
It would be a low BP
As the blood crosses the pressure of high resistance, our blood pressure is?
Reduced
Normally when we take BP measurements, we use _____ arteries.
Big
What happens to our BP as they go through more and more cross sectional areas?
(more cross sectional areas = more small arteries/arterioles involved)
BP is down
Why does the BP get lower as it goes through the multiple small/smaller arteries?
(more pathways)
It is due to the high vascular resistance that the blood is encountering from the larger arteries down to the smaller arteries.
How does pressors work?
Causes the arterioles to constrict and raises BP.
Most of the vessels contracting and relaxing occurs on the?
smaller arteriole side of systemic circulation
Ohm’s Law
V = IR
Measurement of the difference in pressure between two points in a system is?
Delta P (AVG 17.3)
What happens to the flow if the delta P goes up?
The flow goes up.
What happens to the flow if resistance goes up?
The flow goes down
What’s the difference between a peripheral capillary and the kidney capillaries?
Kidney capillaries are specialized
What occurs in the peripheral capillaries?
Nutrient exchange, waste product collections from the circulation.
What controls the blood flow through the capillaries?
arteriole blood vessels
Arterioles are equipped with ___ to help with ____ and____ to regulate ____ downstream?
Smooth muscles; contracting; relaxing; blood flow
We have about ____ capillaries, with ____ surface area.
10+ B; 500-700 Sq. meters
What is VSMC’s?
Vascular smooth muscle cells
How many layers of VSMC’s are in capillaries?
4 layers thick for contraction/relaxation
VSMC’s regulate _____ downstream.
blood flow
Process of endothelium-mediated catecholamine NO system
Shear force > eNOs and
binds with o2+ L-argenine > NO+ L-citrulline > soluble guanylyl cyclase > cGTP into cGMP > relaxation
How are gasses offloaded in the capillaries?
It offloads O2 and pickup CO2 to deliver it to the lungs to be excreted.
we have 1 aorta; Internal diameter of the aorta is; cross-sectional area is; leading to a ____ velocity
2.5cm; 4.5sq/cm ; high velocity
we have 2 vena cava; internal diameter; cross-sectional area
3cm; 18sq/cm (total for 2)
Arterioles internal diameter; wall thickness is
30 micrometers; 20 micrometers leaving a 10 micrometer opening
TF: arterioles have really thick walls d/t VSMC’s
True
T/F: capillaries are made up of endothelial cells and unable to contract/relax
True
Does Epi work on the capillaries?
No, they aren’t equipped with VSMCs
If waste products need to be removed from the tissues it ____ the capillaries.
goes into
If the tissues need nutrients from the capillaries, it ____ of the capillaries.
goes out (reabsorbed)
Capillaries cross sectional area
4500 sq/cm
Which part of the circulation has the fastest blood flow velocity? slow? fairly slow?
Aorta; veins; capillaries
The more numbers of same type pathways (capillaries; arterioles; arteries)
the higher the number of cross sectional area
Does the vena cava have a bigger cross sectional area than the aorta?
Yes, because we have 2 vena cavas.
Blood pressure of the arterial end (arteriolar) of the capillary is?
30mmHg
Blood pressure of the venous end of the capillary is?
10mmHg
If the BP is 100 upstream (closer to the heart) what is it in the capillaries?
30mmHG
What is the delta pressure if the arterial end is 30mmHG and venous end is 10mmHG?
delta P = 17.3 mmHG
What does it mean by pressures in the circulation system?
MAP
What is the normal MAP for our class?
100mmHG
What are variables that are filtered in the arterial end?
Glucose, oxygen (filtered)
What are variables that are reabsorbed in the venous end of the capillaries?
Waste products (reabsorption)
What are capillary starling forces?
This determines the movement of fluids between capillaries and tissues (Filtered/reabsorption)
What is P(cap)? (ex. 30 mmHg; arterial, 10mmHG; venous)
BP in the capillary; Hydrostatic/hydraulic/physical fluid pressure
How thick are capillaries?
1 cell layer thick
What is P(ISF)?
BP outside the capillary/cells (interstitial); hydraulic/hydrostatic pressure
What happens if the P(ISF) is high (ex. 10mmHg)? (nml -3mmHg)
It can oppose (impair) the filtration pressure on the arterial end of the capillary and promoting more reabsorption in the venous end
What is the normal P(ISF)?
-3mmHg
What pulls extra fluid out of the intersititium?
Lymphatic system (kind of like a vacuum)
(Pi symbol) CAP; Plasma colloid osmotic (oncotic) pressure means….
in a nml person;
when all the colloids dissolved in the blood hold the fluids inside the capillary (28mmHg)
What happens to the plasma colloids osmotic pressure when we hemorrhage?
colloids decrease and lowers the colloid pressure making it hard to keep fluids in the capillaries (CV system)
If something makes the walls of the capillary more porous, what happens? (ex. sepsis)
we lose osmotic pressure l/t loss of colloids, because it is not a semi permeable membrane anymore.
What are proteoglycan filaments?
Large strings of protein that hang out in the interstitial space (ISF)
What are hyaluronic acid?
Large compound that doesn’t move in or out of the capillary easily. (ISF)
What are collagen?
Proteins found in the ISF.
T/F: There are more proteins found in the ISF vs the CV system (capillaries)
False
What is the (Pi symbol)ISF?
8mmHg that promote fluid into ISF but outweighed by 28mmHG (pi symbol) CAP inside the capillary.
What happens to the capillaries after a trauma or bang your head on something, infection, cells dying?
Causes the capillaries to implode and leak proteins and fluid into the interstitium (swelling)
What happens to the proteins that leaked out from the porous capillaries after the capillary heals?
All of the proteins are stuck in the ISF bc it is now back to a semi permeable membrane. (Swelling/edema that’s harder to fix)
*Lymphatics try to help but it’s a slow process.
How does your body fix itself when there are proteins stuck in the ISF?
The lymphatic system can help by “vacuuming” some of the extra proteins/fluids out if the ISF. But this is a very slow process.
How does the lymphatic system work?
Their rate of action is activated by activity (skeletal muscle). More slowed in someone who’s bedridden or immobile.
What does the lymphatic system mainly work on?
Managing excess fluids more than proteins but it does help remove excess proteins a little bit.
What other things does a surgeon worry about when making incisions?
Worried of cutting the lymphatic system that causes fluids to continuously leak out.
What is Kf? what effects will it have if the surface area is increased? (filtration coefficient)
- measures how permeable capillaries are to fluids not proteins.
- If the surface area gets bigger, the permeability # also increases.
3 main protein compounds that make up total oncotic pressure in the capillary (CV system)
- albumin, fibrinogen, globulins (28mmHg)
Effects of activity (walking) on the lymphatic system.
When walking, leg muscle movements will compress/relax the lymphatic systems in the area and activate them as well as arm movements. (one way pumping system)
Where does the lymphatic system return all the excess fluids?
Lymphatic ducts on the top of the thorax connected to very large veins.
(subclavian veins)
Lymphatic flow starts as low as ___. As we increase activity it can go as high as ___ capacity.
1; 20
How does being bed ridden affect the lymphatic system and how can you prevent it?
Bed ridden = immobility, l/t lymphatic system to work slower, excess fluids in ISF to “pool”.
- SCD’s can prevent this issue
(Arterial)
What is the (NFP; Net Filtration Pressure) filtration pressure of filtration minus the opposing filtration pressure?
(Arterial);
Net Filtration Pressure (NFP); 13mmHG
- favors filtration
(Venous)
What is the Net filtration pressure (NFP) minus opposing pressure?
Net filtration pressure (NFP); (Venous)
-7mmHg
- favors reabsorption
What happens to the excess fluid that’s from the NFP of the arteries minus the venous NFP?
scavenged by the lymphatic system.
What is the “average” Pressure and NFP in the capillary?
17.3mmHg MAP
Average NFP 0.3mmHg
What is the capillary generally permeable to?
water, NaCl (smaller the compound the easier the permeability) Glucose not really but in the BBB they require glucose transporters.
What is the normal pressure in the renal artery?
100 MAP
What are the 1st set of renal capillaries?
glomerular capillaries control the amount of filtering
afferent arteriole (renal) has a lot of resistance causing the 100mmHg to?
drop to 60mmHg by the time it reaches the Glomerular capillaries
T/F: The pressure in the renal capillaries are twice as high as the systemic capillary
True
Due to high pressures in the renal capillary, what is the normal filtration rate?
125ml/min
Does the renal capillaries filter large compounds such as blood, proteins?
No, unless the renal system is damaged
What can cause large compounds to be filtered in the renal system?
Diabetes, HTN
How can the afferent areterioles control the normal levels of blood flow and filtration rate?
It can constrict or dilate depending on the pressure coming in.
Due to the high pressure of ___ mmHg inside the glomerular capillaries, it will increase the filtration rate to ___ ml/min
60; 125
What is the filtration rate dependent on?
Kidney flow (autoregulation) of pressure in the glomerular capillaries.
