Body Fluids and membrane

Question 1

What is the fluid inside the cells?

Answer 1

Intracellular Fluid

Question 2

What is extracellular fluid?

Answer 2

ALL the fluid OUTSIDE the cells

Question 3

How many Litres of FLUID are there within the body

Answer 3

42

Question 4

Of the all the litres in the body, how many litres is Intracellular and extracellular?

Answer 4

25 L = Intracellular
17 L = Extracellular fluid

Question 5

How is EXTRACELLULAR fluid subdivided, also indicate amounts.

Answer 5

1) INTERSTITIAL FLUID = 13 L
2) BLOOD PLASMA = 3 L
3) TRANCELLULAR FLUID = 1 L

Question 6

What is INTERSTITIAL fluid?

Answer 6

Fluid that is OUTSIDE blood and your cells, it baths the cells of the body.

Question 7

What is TRANSCELLULAR fluid?

Answer 7

Transcellular fluid is A body fluid that is not inside cells but is separated from plasma and interstitial fluid by cellular barriers.

Question 8

Give examples of TRANSCELLULAR fluid? (6)

Answer 8

• Cerebrospinal Fluid
• Urine
• Gastrointestinal secretions ( saliva, pancreatic juice, bile)
• Sweat
• Aqueous and Vitreous Humor
• Synovial Fluid Joint.

Question 9

Define OSMOLALITY?

Answer 9

Attractiveness of a SOLUTION to water

Question 10

How is osmolality maintained constant within all types of fluid in the body?

Answer 10

Due the specific electrolyte COMPOSITION of each fluid.

Question 11

What is particular about the electrolyte composition of TRANSCELLULAR fluid?

Answer 11

electrolytes fluid within the transcellular fluid varies according to the function of the transcelullar fluid

Question 12

why is important to maintain constant OSMOLALITY within each fluid?

Answer 12

osmolality always remains constant. This prevents net movement of WATER

Question 13

Describe the route of the fluids that enter your body.

Answer 13

• Fluids enters your body and then moves from PLASMA in the blood to interstitial fluid through endothelium, and then it can move either in the intracellular fluid so inside cells or transcellular fluids.

Question 14

structure of the plasma membrane.

Answer 14

• Highly selective permeability
• Lots of transport proteins for uptake and removal of specific solutes
• Vital for regulation of the intracellular environment
• Phospholipid bilayer- allow movement of lipid soluble and molecules that can pass through with specific channel/carrier/pumps proteins

Question 15

Which processes and protein are involved in the transport of molecules across membrane.

Answer 15

• Simple diffusion (small lipid soluble molecules)
• Channel/ Carrier protein- allow the movements of specific ions only DOWN concentration gradient.
  Active transport from high to low concentration gradient through channel protein, using energy provided by ATP hydrolysis.

Question 16

Types of carries protein:

Answer 16

· Uniport/Facilitator = Transports only one type of ion.
· Co-transporter/Symport = Transports 2 different ions species in same direction down conc gradient (often one is negative and the other positive ion, so the charges cancel out)
Exchanger/ Antiport = Swaps ions, one ion in and out keeping electrical charge neutral.

Question 17

Describe what barriers plasma nutrients/ water have to cross to reach ICF/TF

Answer 17

Plasma nutirents - Andothelium - Interstial fluid - epithilium - ICF/TF

Question 18

Using the picture on the right describe in detail how pH and how cell prevents bursting or shrinking.

Answer 18

K+ is moved against its concentration gradient from high concentration outside the cells (interstitial fluid) to low concentration in intracellular fluid. Na+ is also actively transported outside cells.
The energy released for the pump allows the cell to set a gradient for the movement of other Ions in and out of the cells.
As Na+ is pumped out of the cell it lowers the concentration of Na+ inside the cell, so sodium moves in from outside of the cell down the concertation gradient trough a Exchanger/Antiport carrier protein swapping H+ ions outside the cell if conditions are too acidic.
If the cells need to export base Cl- will move down the concertation gradient inside the cell and swapped with positive base (HCO3+) which will be exported lowering ph. No energy is used here, simply exploited the gradients.
Cell can increase their volume by importing Na+/K+/Cl- which lower water potential gradient so water moves in down concentration gradient.
Cell can decrease volume of cells by exporting Cl-/K+ through channels and thanks too potassium/sodium pump, Cl- and K+ are pumped out of the cell increasing water potential inside cell so water moves out the cell by osmosis decreasing cell volume.

Question 19

Is K+ lower in ICF or ECF?

Answer 19

• Higher in ICF
• Lower in ECF

Question 20

is Na+ lower in ICF or ECF?

Answer 20

Lower inside, higher outside

Question 21

is Ca2+ lower in ICF or ECF?

Answer 21

Lower(very low) inside, higher outside

Question 22

Is Cl lower in ICF or ECF?

Answer 22

Lower inside, higher outside

Question 23

Is org- lower ICF or ECF?

Answer 23

Higher outside, Lower inside

Question 24

Is protein lower ICF or ECF?

Answer 24

Higher outside, lower inside