Week 13 Flashcards
What is ICF:
Intracellular fluid is the fluid inside the cells
What is ECF:
Extracellular fluid is any fluid outside the cells and could be:
Intravascular: inside the vascular compartment
Extravascular: outside the vascular component i.e.
Interstitial: in between tissue cells
3rd spaces: in cavities for example, peritoneal cavity (ascites) or thoracic cavity (cardiac tamponade
What % does ICF make up of the body’s fluid
Intracellular fluid (ICF) – makes up approximately 2/3 of the body’s fluid and 40% of total body weight.
What % does ECF make up of the body’s fluid
extracellular fluid (ECF) – makes up approximately 1/3 of the body’s fluid and 20% (15% interstitial/ 5% plasma) of total body weight.
What is Osmosis:
Movement of water across a semi-permeable membrane from an area of low high concentration of particle/solutes to an area of high concentration
What is Osmolality/Osmolality:
refers to the concentration of solutes or particles in fluid.
How is fluid balanced maintained through Hypothalamic Regulation
receptors in the hypothalamus detect change in osmolality (milliosmoles per kg)
How is fluid balanced maintained through Renal Regulation:
kidneys regulate water balance through adjustments in urine volume & excretion of most electrolytes
What does the Antidiuretic Hormone do?
Decrease urine production
Decrease sweat
Increase blood pressure
If fluid is in a deficit what does the Antidiuretic Hormone do?
ADH is released
If fluid volume is excess what does the Antidiuretic Hormone do?
ADH is inhibited
+ve electrolyte particles =
cations
-ve electrolyte particles =
anions
Sodium (Na+) role 135-145 MMOL/L
Main cation of ECF
Influences water distribution between ECF and ICF
Important for the transmission of nerve impulses
Important for muscle contractility
Plays a role in the regulation of acid-base balance of the body
What is hyponatremia?
less than 135mmol/L of sodium
What is hypernatremia
Excess sodium greater than 145mmol/L
Potassium role and normal range
3.5-5.5 mmol/L
Major ICF cation (98% of potassium is intracellular).
Plasma potassium levels are the ones measured.
Nerve impulse transmission & important in setting the resting membrane potential-
Maintenance of normal cardiac rhythm
Skeletal and smooth muscle contractions
Aids in acid-base balance.
Cellular metabolism.
Released when cells are destroyed.
ECG of hypokalaemia
Flattened T wave
U wave
ST segment depression
ECG of hyperkalamia
Tall tented T wave
ST segment depression
Magnesium role and range
0.7 - 1.1 mmol/L
Activates intracellular enzymes
Transmission of neural activity
Myocardial functioning
Calcium role and range
2.3 - 2.5 mmol/L
Transmission of nerve impulses, cardiac & muscle contractions
Formation of teeth & bone
Blood clotting
Phosphate role and range
0.8 - 1.4 mmol/L Bone development Cell function (ATP) Formation of red blood cells Metabolism of carbohydrates, protein, & fat Nerve & muscle function Maintenance of acid/base balance
Normal body pH
pH 7.35 – 7.45
What is the range for acidosis
BELOW 7.35
What is alkalosis
ABOVE 7.45
3 mechanisms that work to maintain acid balance:
The buffer system
The respiratory system
The renal system
Increase in H+ ion concentration leads to
acidity (acidosis)
Decrease in H+ ion concentration leads to
alkalinity (alkalosis)
What are the three systems that make up the buffer system
Bicarbonate-carbonic acid
Phosphate buffer system
Protein buffers
BICARBONATE range and use
24 - 30 MMOL/L
Intra/extracellular anion
Needed for buffering system to maintain acid/base balance by managing the release of carbon dioxide as a bi-product of cellular metabolism
PHOSPHATE BUFFER SYSTEM two ions
Hydrogen phosphate ions – accepts all additional hydrogen ions to reduce the amount in the blood
Dihydrogen phosphate ions – release additional hydrogen ions to increase the amount in the blood
What are PROTEIN BUFFERS
Are intracellular and extracellular
Include basic acidic protein buffer groups
Act to deplete hydrogen ions or to donate more hydrogen ions when needed
Respiratory Acidosis range and cause
pH <7.35 & PaCO2<45
Occurs due to a carbonic acid excess, resulting from increased LEVELS OF CARBON DIOXIDE in the circulatory system
Respiratory alkalosis range and cause
pH >7.45 & PaCO2 <35mmHg
Occurs due to a carbonic acid deficit as a result of decreased levels of carbon dioxide in the circulatory system.
Metabolic acidosis range and cause
pH<7.35 & HCO3- <22mmol/L
Occurs due to a base bicarbonate deficit resulting when an acid, other than carbonic acid, accumulates in the body or when bicarbonate is lost from body fluids.
Normal PaCo2 levels
35-45 mmHg
Metabolic alkalosis range and cause
pH >7.45 & HCO3- >26mmol/L
Occurs due to there is an excess of bicarbonate due to a loss of acid or a gain in bicarbonate.
3 components of VIRCHOW’s TRIAD
Venous stasis
Hyper coagulable state
Endothelial injury
What is Hypovolaemia:
The term hypovolemia refers collectively to two distinct disorders: (1) volume depletion which describes the loss of sodium from the extracellular space (i.e., intravascular and interstitial fluid) that occurs during gastrointestinal haemorrhage vomiting, diarrhea, and diuresis; and (2) dehydration, which refers to the loss of intracellular water (and total body water) that ultimately causes cellular desiccation and elevates the plasma sodium concentration and osmolality
What is Hypervolaemia:
Excessive fluid volume occurs when there is retention of both electrolytes and water relative to the levels in the extracellular fluid. This may be caused, for example, by sodium retention that leads to the retention of water. As a result, excess fluid leaks into the interstitial spaces and forms oedema. This normally happens in people with long-term conditions, such as renal impairment and liver disease
Capillary hydrostatic pressure:
The pressure exerted by the water/fluid will push fluid out of the capillary to the interstitial space
Capillary Oncotic Pressure:
The pressure exerted by the plasma proteins and will draw fluid back into the capillaries.
Interstitial hydrostatic pressure: The pressure exerted by the fluid in the interstitial space, will force fluid back into the capillaries
Interstitial oncotic pressure:
The pressure exerted by the small amount of proteins in the interstitial space from the capillaries
Thus: Hydrostatic pressure:
pushes fluid out and Oncotic Pressure, pulls fluid into the space
Crystalloid -
contain small molecules that flow easily across semipermeable membranes from the bloodstream into the cells and body tissue. Categorised as; isotonic, hypotonic or hypertonic.
