Topic 5

Question 1

What is pressure defined as?

Answer 1

The force per unit area in a gas or a liquid.

Question 2

What is the unit of pressure?

Answer 2

Pascal (Pa), equivalent to Newtons per square meter.

Question 3

What is standard atmospheric pressure at sea level in kPa?

Answer 3

101 kPa.

Question 4

How is pressure commonly indicated in medicine?

Answer 4

By the height of a column of mercury (mmHg).

Question 5

What is the relationship between mmHg and kPa?

Answer 5

1 mmHg is equal to 0.133 kPa.

Question 6

What distinguishes fluids from solids at the molecular level?

Answer 6

Fluids deform continuously under shear stress, while solids resist shear stress.

Question 7

What is normal stress?

Answer 7

The normal component of a force acting on a surface per unit area.

Question 8

What is shear stress?

Answer 8

The tangential component of a force acting on a surface per unit area.

Question 9

What is the significance of zero shear stress in fluids?

Answer 9

A fluid at rest is in a state of zero shear stress.

Question 10

What happens to a gas when it is placed in a container?

Answer 10

A gas expands until it fills the entire available space.

Question 11

What is the density of blood plasma?

Answer 11

Approximately 1025 kg/m3.

Question 12

What is gauge pressure?

Answer 12

The pressure relative to a standard atmospheric pressure.

Question 13

How is the pressure in the bladder measured?

Answer 13

Using cystometry, which measures forces in the bladder.

Question 14

What is the typical range of pressure in normal eyes in kPa?

Answer 14

1.6 to 3 kPa.

Question 15

What condition is caused by increased pressure in the eyeball?

Answer 15

Glaucoma.

Question 16

What device is commonly used to measure blood pressure?

Answer 16

Sphygmomanometer.

Question 17

What are Korotkoff sounds?

Answer 17

Sounds heard when measuring blood pressure due to turbulent blood flow.

Question 18

What is the pressure in the major arteries during a heartbeat cycle?

Answer 18

Varies between 120 mmHg (systolic) and 80 mmHg (diastolic).

Question 19

What happens to bladder pressure during sneezing or coughing?

Answer 19

Bladder pressure increases.

Question 20

What is the highest pressure found in the body?

Answer 20

Stresses in weight-bearing bone joints, exceeding 106 Pa.

Question 21

How does a manometer measure pressure?

Answer 21

By the height of the fluid column plus the reference pressure.

Question 22

Fill in the blank: A fluid must assume the shape of the _______.

Answer 22

container.

Question 23

Fill in the blank: A solid is able to sustain its own _______.

Answer 23

shape.

Question 24

True or False: A gas can form a free surface in an open container.

Answer 24

False.

Question 25

What happens to the size of veins in the hand when it is raised above heart level?

Answer 25

Veins become smaller due to lower venous blood pressure.

Question 26

What is the relationship between the height of a fluid column and pressure?

Answer 26

Pressure is proportional to the height of the fluid column.

Question 27

What is hydrocephalus?

Answer 27

A condition caused by trapped cerebrospinal fluid increasing internal pressure in the skull.

Question 28

What external factors can affect gut pressure?

Answer 28

Belts.

Question 29

What are the pressure levels in GI + esophagus?

Answer 29

• GI = > atm
• Esophagus = < atm