Question

Please help with question 20 and 21

QUESTION 20 During light to moderate exercise there is he resistance. widespread vasodilation of blood vessols serving metabolically active tissue, the dilation of these blood vessels decreases False QUESTION 21 "co and R went increased equaly then MAP would CO and R decreased equaly then MAP would R decreased then MAP would --" but ico increased more significantly then R decreased then MAP would If CO increased just as much as O increase, decrease, stay the same; increase decrease, increase; stay the same; increase Ostay the same; increase; stay the same, decrease increase; increase, stay the same; increase

Answer 1

20.

According to Poiseuille's equation resistance in blood vessels is Here r is radius of vessel, n is viscosity of blood and L length of vessel.

According to Poiseuille's equation resistance in blood vessels is R = eta L/r^4 Here r is radius of vessel, n is viscosity of blood and L length of vessel . So, according to this formula resistance in blood vessel will decrease if radius increases. In this case vasodilatation will increase the radius of the vessels, so resistance will decrease. So answer is�TRUE Increase, Decrease, stay same, Increase We know that: Total Peripheral Resistance (R) = (Mean Arterial Pressure - Mean Venous Pressure)/Cardiac Output Or R = (MAP -Mean venous pressure)/CO or MAP = R times CO + MVP(can be neglected as its value is very small) so, MAP = R times CO if CO & R increases MAP will increase. If CO & R decreases MAP will decrease. If CO increases as much as R decreases then MAP will remain same. If CO increase more significantly than R decreases then MAP will increase

So, according to this formula resistance in blood vessel will decrease if radius increses. In this case vasodilatation will increase the radius of the vessels, so resistance will decrease.

So answer is TRUE

21. Answer is option 1 : Increase, Decrease, Stay same, Increase

We know that : Total Peripheral Resistance (R) = (Mean Arterial Pressure - Mean Venous Pressure) / Cardiac Output

Or R =(MAP -Mean venous pressure) / CO

or MAP = R x CO + MVP( can be neglected as its value is very small)

so, MAP = R x CO

if CO & R increases MAP will increase.

If CO & R decreases MAP will decrease.

If CO increases as much as R decreases then MAP will remain same.

If CO increase more significantly than R decreases then MAP will increse.