physics chapter4

Question 1

Column A (Question)

Answer 1

Column B (Answer)

Question 2

What does Kf represent in the context of capillary filtration?

Answer 2

Kf represents the filtration coefficient, which is a product of the capillary wall area where flux can occur and the wall’s permeability to water flux.

Question 3

What are Pc and Pi in the Starling equation?

Answer 3

Pc is the hydrostatic pressure in the capillary, and Pi is the hydrostatic pressure in the interstitial space.

Question 4

What does the reflection coefficient (σ) indicate?

Answer 4

The reflection coefficient (σ) describes the capillary’s permeability to proteins. A value of 1 means impermeable, and 0 means completely permeable to proteins.

Question 5

What are πc and πi in relation to fluid movement?

Answer 5

πc is the oncotic pressure in the capillary, and πi is the oncotic pressure in the interstitial space, both of which affect fluid movement across capillaries.

Question 6

What fraction of the body’s water is intracellular fluid (ICF)?

Answer 6

Intracellular Fluid (ICF) makes up 2/3 of the body’s water, which is about 40% of the body’s weight.

Question 7

What ions and molecules are primarily found in the ICF?

Answer 7

The ICF primarily contains potassium, organic anions, and proteins. Organic anions are chemically diverse and negatively charged.

Question 8

What fraction of the body’s water is extracellular fluid (ECF)?

Answer 8

Extracellular Fluid (ECF) makes up 1/3 of the body’s water, which is about 20% of the body weight.

Question 9

What is the composition of the ECF?

Answer 9

The ECF is mainly composed of NaCl (sodium chloride) and NaHCO3 (sodium bicarbonate).

Question 10

What is interstitial fluid (ISF) and its role?

Answer 10

Interstitial fluid surrounds the cells, does not circulate, and makes up about 3/4 of the ECF. It provides nutrients and removes waste from cells.

Question 11

How much interstitial fluid does an average person have?

Answer 11

An average person has about 11 liters of interstitial fluid.

Question 12

How does plasma communicate with interstitial fluid?

Answer 12

Plasma communicates with interstitial fluid through pores and intercellular clefts in the capillary endothelium.

Question 13

What is the role of plasma in the blood?

Answer 13

Plasma circulates as the extracellular component of blood, making up about 1/4 of the ECF.

Question 14

What is transcellular fluid and its significance?

Answer 14

Transcellular fluid, about 1-2 liters in total, includes fluids like synovial fluid and cerebrospinal fluid (CSF) and is important for specialized functions.

Question 15

What causes fluid movement between compartments?

Answer 15

Fluid movement is primarily caused by pressure gradients and is influenced by factors like membrane permeability and surface area.

Question 16

What is flux in the context of molecular movement?

Answer 16

Flux is the rate of movement of molecules across a unit area, determined by diffusion across a membrane.

Question 17

What factors affect net flux across a membrane?

Answer 17

Net flux depends on the concentration gradient, the surface area of the membrane, and the permeability constant of the membrane.

Question 18

What is the Péclet number (Pe) used to describe?

Answer 18

The Péclet number (Pe) is a dimensionless number that describes the relative importance of convection versus diffusion in fluid transport.

Question 19

What is osmosis and its primary driving force?

Answer 19

Osmosis is the movement of water molecules through a selectively permeable membrane into a region of higher solute concentration, driven by the solute concentration.

Question 20

What are isotonic, hypotonic, and hypertonic solutions?

Answer 20

Isotonic solutions have equal solute concentrations, hypotonic solutions cause cells to swell, and hypertonic solutions cause cells to shrink.

Question 21

What is oncotic pressure and how does it affect fluid movement?

Answer 21

Oncotic pressure is the form of osmotic pressure exerted by proteins in blood plasma, which tends to pull water into the circulatory system and balance fluid leakage.

Question 22

What is the Starling equation used for?

Answer 22

The Starling equation determines fluid movement by summing hydrostatic and oncotic pressures across a capillary wall.

Question 23

What does a positive net filtration pressure (Jv) indicate in the Starling equation?

Answer 23

A positive Jv indicates filtration, meaning fluid is moving out of the capillaries and into the interstitial space.

Question 24

What is edema and how can it occur?

Answer 24

Edema is the buildup of excess fluid in tissues, often due to a decrease in oncotic pressure from protein loss or malnutrition.

Question 25

What is the filtration coefficient (Kf) in the Starling equation?

Answer 25

Kf is the filtration coefficient, which measures the permeability and surface area of the capillary wall for fluid movement.