Question

MCAT Biology Tutorial: Blood Pressure & Flow

Answer 1

\({\bf{Measuring~Blood~Pressure:}}\) systole: the contraction of the blood vessels, highest pressure
diastolic: relaxation of ventricles, lowest pressure

flow = (delta P)/R where P = pressure and R is resistance

can also use Poiseuille's Law (see hydrostatics tutorial)

highest in the aorta and lowest in veins

blood does not perfectly follow bernoulli's b/c it's not ideal fluid

\({\bf{Regulating~Blood~Pressure:}}\)
- blood pressure must be maintained to exchange nutrients/waste in the capillaries
- total peripheral resistance: resistance of the entire circulatory system
- changed by changing the output level of the heart & the muscle lining of arterioles

- two methods:
> baroreceptor reflex (quick).
- changes cardiac output and resistance
- activates SNS or PNS (depending on whether the pressure needs to be raised or lowered)
- uses baroreceptors in arteries

> renin-angiotensin-aldosterone: (will refer to this as angiotensin system from now on)
- changes volume of plasma
- uses mechanoreceptors to signal to kidneys to secrete hormones
- renin --> increase blood volume through water intake --> increase in blood pressure

Answer 2

\({\bf{Fluid~Exchange~in~the~Capillaries:}}\)
- low overall pressure
- two ends of a capillary (arteriole end and venule end)
- at arteriole end, hydrostatic pressure is high compared to osmotic, so blood diffuses out
- at venule end, the hydrostatic pressure is lower b/c of the fluid that has exited, and now the fluid will flow back into the capillary
- throughout this process the osmotic pressure is relatively constant so the exchange is governed by the hydrostatic pressure differential

blood is not ideal but can be approximated w/ continuity Q = Av where velocity is inversely proportional to cross-sectional area assuming constant flow

Answer 3

Anyway, that's the end of my tutorial, I hope it was a helpful resource. Source material is the 9th Edition ExamKracker's Biology 2 Prep book for the new MCAT

Answer 4

In what contemporary genre is an essay such as Joseph Bruchac's u201cKeepers of the Earthu201d memoir best classified?
A.

Answer 5

There was a story that the present box had been made with some pieces of the box that had preceded it, the one that had been constructed when the first peop

Answer 6

Find the derivative of

Answer 7

PLEASE HELP!!
Complete the analogy below.
amplitude : loudness :: frequency : _________
A.

Answer 8

PLEASE HELP!!
Sound waves can best be described as _________.
A. opaque
B. polarized
C.

Answer 9

Which of the following major contributions were made by Maury?

creating navigati

Answer 10

Cousteau and Gagnan _____.

invented SCUBA
lived in Sealab II
developed u201csign

Answer 11

A scientist is studying the effect on human health of bacteria that live in the human intestine.

Answer 12

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Answer 13

Find the derivative dy/dx if

Answer 14

Alice wanted to compare birthday cake prices in two supermarkets. She wrote down the daily prices for a few days and found that the difference of the two sa

Answer 15

which of the following was directly caused by germanys invasion of Belgium

Answer 16

How do Hallyu2019s memories help advance the plot?

They suggest that Hally is afraid of his father.

Answer 17

math help pls

Answer 18

"If we fight the stranger, we shall hit our brothers and perhaps shed the blood of a clansman.

Answer 19

... help please? am i right?
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Answer 20

Solve.
33=8^5z+4

Answer 21

A car is moving southwest at a velocity of 10 meters per second. Five seconds later, it's going 40 meters per second.

Answer 22

If you run 10 km east and then turn around and run 7 km west, how much total distance have you travelled?
A.

Answer 23

Which of the following is a vector measurement?
A. 0.08 g/L
B. 6.5 m/s down
C. 45 m/s slowly
D. 15 km/hr