Liquides Biologiques 1 Flashcards
Osmose
Diffusion de l’eau, suivant son gradient de concentration, au travers d’une membrane à perméabilité sélective
What % of total body weight will be water?
60%
What is the separation of body water for intracellular, extracellular, and transcellular?
<1%: Transcellular (pleuvre, sereuse)
2/3 Intracellulaire
1/3 Extracellulaire
What is liquid intersitiel?
Liquid dans lequel les cellules baignent
What is the separation of body water for plasma, intertitiel liquid and lymphatic liquid?
10% lymphatic
3/4th of extracellular liquid is intersitiel
1/4th of extracellular liquid is plasma
What is the most important and abundant blood protein?
What is the role of albumin?
Albumin
Because it is a huge protein and cannot leave blood vessels, it creates a oncotique pressure. It creates an osmolarity barrier that keeps the water inside the blood vessels.
What are Liquides transcellulaires?
Liquide formé par l’activité sécrétoire des
cellules de certaines cavités anatomiques
épithélialisées (ex. pericarde, plèvre, CSF, all the liquid in the digestive tract; urine etc.)
The plasma [Na+] and interstitial [Na+] are basically the same. What does this mean?
The endothelium membrane that lines the blood vessels (membrane capillaire) is permeable to Na+ (ions)
What can pass through the membrane capillaire?
Everything but proteins can pass.
What is the main difference between the intracellular membrane and capillary membrane?
intracellular membrane is impermeable to virtually all substances but water!!!!
(it can still allow things to go through via facilitated diffusion or active)
What is special about uree and glucose diffusion?
They diffuse basically freely through the membrane
As soon as glucose is available it is basically instatly absorbed by the cells
Vous pensez à donner un bolus (1 L) de solution de NaCl 0.9% (154 mmol/L) à un de vos patients. Dans quel compartiment est-ce
que les 154 mmol de NaCl se distribueront après l’injection?
You would think interstitiel space but because Na+ and Cl- are freely diffusable between the capillary, the concentration will be balanced and so, we find it in the extraceluular space (which includes interstitiel and plasma)
Vous faites des études sur la perméabilité de
la membrane capillaire chez les patients
atteints d’un cancer. Vous observez que
l’endothélium contient des pores élargis et
déformés chez ceux-ci. Quel sera l’impact
dans le plasma?
- A. Hypoalbuminémie
- B. Hyponatrémie
- C. Hypernatrémie
- D. Hyperglycémie
Hypoalbuminémie
What are the molecules used to estimate plasma concentration?
Osmolarité ≈ [Na] x 2 + [Urée] + [Glucose]
What is a normal blood plasma concentration?
[NaCl] = 140 mmol/L, [Urée] = 5 mmol/L, [Glucose] = 5 mmol/L
[NaCl] x 2 + [Urée] + [Glucose] = 290 mOsm/
What is osmolarite efficace?
If a membrane is permeable to an ion or etc, then the efficace osmolarity for that ion is 0. This is because it can freely diffuse to balance concentrations and thus not need water to come in an balance.
What is tonicity?
mesure du gradient de pression osmotique établi entre deux solutions séparées par une membrane sélectivement perméable
can be iso-, hypo- ou hypertonique
Détermine la direction du mouvement de l’eau entre les solutions dépend de l’osmolarité efficace
__________ se dissocient en solution (ex. NaCl à Na+ et Cl-), et génèrent donc > 1 mole de particules osmotiquement actives par mole de soluté.
Electrolytes
What does it mean for a cell to be in a hypotonic, or hypertonic solution?
Hypotonic: there are more mmoles (higher osmolarity) inside the cell
Hypertonic, the cell’s water wants to leave to dilute
What is the pression osmotique colloidale?
Refers to the pressure generated by the proteins that are in the plasma
This is what pulls water inside the plasma from the liquid interstitiel
This is important for reabsorbation
What is pression hydrostatique?
Pressure created by constricting a vessel
The heart is the main generator of hydrostatic pressure
This is what pushed water outside of the capillaries into the interstitial space
This is important for filtration of material
expliquer une diminution de du liquide interstitiel ramené vers le plasma
↑ (aug) Pression hydrostatique
↓ (baise) Pression osmotique
↓ (baise) Pression oncotique
Atteinte lymphatiques (why? ; because this is the network that is key for reabsorption of any lost water in the interstinial space)
What is hypovolemie vs deshydratation?
hypovolemie: loss of water in plasma with inbalance in osmolarity between compartments
deshydratation: total loss of water due to diarrhea or other
