Chapter 4:

Question 1

Define hydrostatic pressure:

Answer 1

The pressure exerted by a fluid, at a given point in the fluid, due to the force of gravity. This is the pressure created on a blood vessel, from the blood flowing within it.

Question 2

If the hydrostatic pressure of a blood vessel that supplies an organ is increased, which of the following would occur?

a. The oncotic pressure will increase.
b. The organ will increase in mass and weight.
c. The blood flow to the orgall decreases.
d. The oncotic pressure will decrease.

Answer 2

b. The organ will increase in mass and weight - because as hydrostatic pressure increases, more fluid will leave the blood vessel and enter the organ tissue.

d. The oncotic pressure will decrease -

Question 3

What does oncotic pressure do physiologically?

Answer 3

Pull water back into the bloodstream, thanks to the concentration of large solutes (albumin) in the plasma.

Question 4

Pressure in a blood vessel:

Answer 4

P = pgh

p = density of a fluid.
g = acceleration due to gravity.
h = height.

Question 5

When arterial pressure and venous pressure are equal:

a. The venous return from the supplied tissue will increase.
b. The volume of blood supplied to the tissue will increase.
c. The flow of blood between the blood vessels and tissue will be almost 0.
d. The flow of blood through the vessels will halt, and there will be no oxygenation of tissues.

Answer 5

c - The blood flow between the blood vessels and tissue will be almost 0.

When arterial = venous, there is no net change in blood exchange between a vessel and its target tissue.

Question 6

An incompressible solid plastic bowling ball with a density of 1.32 g/cm^3 is held at a depth of 10 m in a freshwater lake. When released, the ball will:???????????????

a. Sink with an initial velocity of 3.3 m/s.
b. Sink with an initial acceleration of 2.5 m/s.
c. Sink with an initial acceleration of 9.8 m/s^2.
d. Float upward with with an initial velocity of 3.3 m/s.

Answer 6

Sink with an initial acceleration of 2.5 m/s.
Since the ball is more dense than water, it will sink.

a = (Fg - Fb)/m
Fq = mg = (mvol)(9.8) – Mass and volume of ball.
Fb = mg = (mvol)(9.8) — Mass and volume of water.

Question 7

What is the density of water?

Answer 7

1 g/cm^3

Answer 8

1. Heart to lungs - Blood raises up slightly, causing an increase in gravitational potential energy.
2. As blood goes back to the heart it will go back to the initial gravitational potential energy.
3. As blood leaves the heart and goes up the aorta, the gravitational potential energy will slightly increase.
4. As blood leaves the aorta and goes into peripheral vessels, the gravitational potential energy will drastically decrease.
5. As blood returns to the heart via venous return, gravitational potential energy is slowly (venous return is slow) increasing back to the initial gravitational potential energy.

DRAW OUT AS A GRAPH!

Question 9

In order for an object to float in a fluid, what must be true?

Answer 9

Fb = Fq

Fb = boyant force.
Fg = Gravitational force.

Question 10

If a 78 kg woman lays with 1/10th of herself submerged in a body of water. At what gravitational force would this woman NOT float?

a. 12.5 N.
b. 0.6 N.
c. 9.8 N.
d. The woman would float at any of these.

Answer 10

Fb = Fg

FB = (density)(volume) (gravitational acceleration) = pVg.

FG = (mass)(gravitational force) = m*g

mg = pV*g Gravitational acceleration will cancel out

m = p*V - Now the woman will always float.

Question 11

Equation for buoyant force of a fluid:

Answer 11

Fb = p * V * g

p = density of the fluid.
V = volume of the fluid.
g = Gravitational acceleration (9.8 m/s^2)

Question 12

Which of the following can fluids be:

a. solid.
b. gas.
c. liquid.

Answer 12

B & C.

Question 13

True or false: Both gasses and liquids can be compressed.

Answer 13

FALSE - only gases can be compressed and have no shape, while liquids can’t be compressed and fill the shape of their container.

Question 14

Define density and what equation:

Answer 14

Density is the ratio of a substances mass to volume.

P(ro) = m/V

Mass/Volume

Question 15

When will a substance sink in water? When will it float?

Answer 15

A substance will float in water if it’s density is less than waters (1 g/cm^3 or 1000 kg/m^3), and will sink when its density is greater than water.

Question 16

What are the 3 ways we may represent the density of water?

Answer 16

1. 1 g/cm^3
2. 1 g/mL
3. 1000 kg/m^3

Question 17

How may we calculate weight using density of a fluid?

Answer 17

Fg = P(ro)V*g

Question 18

Define specific gravity:

Answer 18

Specific gravity is the ratio of a substance’s density, as compared to that of water. It is unitless.

SG = p/1 g.cm^3

Question 19

If the specific gravity of a substance is less than 1:

a. The substance is more dense than water and will float.
b. The substance is less dense than water and will sink.
c. The substance is less dense than water and will float.
d. The substance is more dense than water and will sink.

Answer 19

c - The substance is less dense than water and will float.

SG = p/ ph2o

Question 20

If the specific gravity of a substance is greater than 1:

a. The substance is more dense than water and will float.
b. The substance is less dense than water and will sink.
c. The substance is less dense than water and will float.
d. The substance is more dense than water and will sink.

Answer 20

d - The substance is more dense than water and will sink.

Question 21

During inhalation:

a. The pressure in the lungs in negative to the external environment, and air will be drawn into the lungs.
b. The pressure in the lungs remains unchanged, but the area will increase.
c. The pressure in the lungs is positive to the external environment, and air will be drawn into the lungs.

Answer 21

a - The pressure in the lungs is negative to that of the external environment, and air will be drawn into the lungs

Question 22

During exhalation:

a. The pressure in the lungs is negative to the external environment, and air will be expelled from the lungs.
b. The pressure in the lungs is positive to the external environment, and air will be expelled from the lungs.
c. The pressure in the lungs remains unchanged, as exhalation is a passive process.

Answer 22

b - The pressure in the lungs is positive to the external environment, and air will be expelled from the lungs.

Question 23

Pressure is a _________, since its force component will be felt equally in all directions (specifically in fluids).

Answer 23

Scalar.

Question 24

You want to analyze the pressure exerted on a balloon at different sizes. If you start at the maximum inflation, and then release 23% of the original area of the balloon, while holding the force constant:

a. The pressure of the balloon will increase.
b. The pressure of the balloon will decrease.
c. Area of the container does not affect the pressure exerted.

Answer 24

A - the pressure in the balloon will increase. Pressure exerted by a fluid is inversely proportional to area of the container.

Pressure = F/A.

F = Force.
A = area.

Question 25

A medical breast implant device is filled with saline with a cross-sectional area of 0.6 m^2. If the force exerted on the walls of the implant is 1.4 newtons, what would be the net pressure experienced by the walls of the implant? a. 2.3 ATM. b. 1.4 ATM. c. 7 ATM. d 0.43 ATM

Answer 25

P = F/A P = (1.4 N) / (0.6 m^2) = 2.3 ATM.

Question 26

1 ATM is equal to (provide all 4 options):

Answer 26

1 ATM = 101,325 Pa (pascals) 1 ATM = 1.01325 Bar 1ATM = 760 Torr. 1 ATM = 760 mmHg.

Question 27

Define absolute pressure:

Answer 27

The total pressure exerted on an object that is submerged in fluid.

Question 28

Define the gauge pressure:

Answer 28

Is the pressure exerted on an object relative to the environmental pressure. Shows how much the pressure inside a system exceeds the standard pressure.

Question 29

Define atmospheric pressure:

Answer 29

The pressure exerted on an object by the weight of the atmosphere above the point of measurement.

Question 30

How do we calculate the absolute pressure?

Answer 30

P = P0 + density * gravity * depth of the object below the surface P0 = Pressure at the surface of the fluid. P = absolute pressure.

Question 31

How do we calculate gauge pressure?

Answer 31

Pquage = P - Patm When P0 = Patm Pguage = Density * gravity * depth of object

Question 32

Negative gauge pressure indicates:

Answer 32

A vacuum - lower pressure in the object than the external environment.