Topic 5 Flashcards
What is pressure defined as?
The force per unit area in a gas or a liquid.
What is the unit of pressure?
Pascal (Pa), equivalent to Newtons per square meter.
What is standard atmospheric pressure at sea level in kPa?
101 kPa.
How is pressure commonly indicated in medicine?
By the height of a column of mercury (mmHg).
What is the relationship between mmHg and kPa?
1 mmHg is equal to 0.133 kPa.
What distinguishes fluids from solids at the molecular level?
Fluids deform continuously under shear stress, while solids resist shear stress.
What is normal stress?
The normal component of a force acting on a surface per unit area.
What is shear stress?
The tangential component of a force acting on a surface per unit area.
What is the significance of zero shear stress in fluids?
A fluid at rest is in a state of zero shear stress.
What happens to a gas when it is placed in a container?
A gas expands until it fills the entire available space.
What is the density of blood plasma?
Approximately 1025 kg/m3.
What is gauge pressure?
The pressure relative to a standard atmospheric pressure.
How is the pressure in the bladder measured?
Using cystometry, which measures forces in the bladder.
What is the typical range of pressure in normal eyes in kPa?
1.6 to 3 kPa.
What condition is caused by increased pressure in the eyeball?
Glaucoma.
What device is commonly used to measure blood pressure?
Sphygmomanometer.
What are Korotkoff sounds?
Sounds heard when measuring blood pressure due to turbulent blood flow.
What is the pressure in the major arteries during a heartbeat cycle?
Varies between 120 mmHg (systolic) and 80 mmHg (diastolic).
What happens to bladder pressure during sneezing or coughing?
Bladder pressure increases.
What is the highest pressure found in the body?
Stresses in weight-bearing bone joints, exceeding 106 Pa.
How does a manometer measure pressure?
By the height of the fluid column plus the reference pressure.
Fill in the blank: A fluid must assume the shape of the _______.
container.
Fill in the blank: A solid is able to sustain its own _______.
shape.
True or False: A gas can form a free surface in an open container.
False.
What happens to the size of veins in the hand when it is raised above heart level?
Veins become smaller due to lower venous blood pressure.
What is the relationship between the height of a fluid column and pressure?
Pressure is proportional to the height of the fluid column.
What is hydrocephalus?
A condition caused by trapped cerebrospinal fluid increasing internal pressure in the skull.
What external factors can affect gut pressure?
Belts.
What are the pressure levels in GI + esophagus?
- GI = > atm
- Esophagus = < atm
