Week 2 - Fluid Dynamics Flashcards
What are three components of body fluids?
• Water
• Electrolytes
• Non-electrolytes
Fill in the blanks in terms of fluid as a percentage of body weight
* Male :
* Female :
* Infants :
* Elderly :
- 60% male
- 50% female
- Infants 70-80%
- Elderly 45%
Name the main intracellular and extracellular ions
• Intracellular = potassium
• Extracellular = sodium
What are the three areas within the extracellular fluid compartment?
- Intravascular* (carries blood)*
- Interstitial* (acts as a reservoir, in gel form)*
- Transcellular (fluid within specialised spaces)
Describe third spacing
Represents the shift of fluid from intravascular space into interstitial and transcellular spaces.
Give three examples of transcellular spaces
- CSF
- Peritoneal space – aka ascites
- Pleural space
- Pericardial cavities
- Joint spaces
- GI tract
Transcellular is fluid contained in specialised spaces, and functions as
What are the three interrelated processes that volume, solutes and pH balance within the body rely on?
- Fluid balance
- Electrolyte balance
- Acid-base balance
Name four ways fluid is lost
- Respiratory
- Sweat
- Faeces
- Kidneys as urine
Name three functions of electrolytes
- Regulate essential mineral and enzymes
- Control osmosis of water between body compartments
- Maintain acid/base balance required for normal cellular activities
- Create action potentials for neurotransmission
An electrolyte is a compound that breaks down into multiple ions.
Describe the difference between electrolytes and non-electrolytes
- Electrolytes are charged ions that dissolve in water
- Non-electrolytes are compounds that do not break into ions and do not conduct electricity.
Give three examples of non-electrolytes
• RBC
• WBC
• Glucose
• Oxygen
• Carbon dioxide
• Urea
• Ethanol
• Water
Describe the difference between simple diffusion and facilitated diffusion
Simple diffusion occurs when a solute crosses a membrane from high to low concentration.
Facilitated diffusion occurs when a lipid soluable carrier protein helps a solute cross an impermeable membrane.
Facilitated:
[High] → [Protein Channel] → [Low]
Simple:
[High] → [Low]
Describe active transport
Moves solutes against an osmotic gradient by using the sodium/potassium pump.
What is the normal pH range of the human body?
7.35-7.45
Name two effects the change in pH has at a cellular level?
• Disrupts the stability of the cell membranes
• Alters protein structure
• Changes the activity of important enzymes
Name three different types of chemical buffer systems
• Phosphate
• Protein
• Bicarbonate
What are the two general causes of oedema?
• Abnormal leakage of fluid from the plasma to the interstitial spaces across the capillaries
• Failure of the lymphatic system to return fluid from the interstitium back to the intravascular space
What are 3 causes of metabolic acidosis?
Shock
Renal/Kidney failure
Hyperglycaemia (DKA)
Seizures
Chemical Poisoning
What are 3 causes of respiratory acidosis?
Asphyxiation
Hypoventilation
Pulmonary Oedema
COPD
Respiratory Depression
Anything that slows down or impairs respiratory function
If pH increases, what does buffers do?
Removes H+
Describe the Bicarbonate Buffer System
CO² & H²O <==> H²CO³ <==> (HCO³) & H+
(carbon dioxide & water <==> carbonic acid <==> bicarbonate & hydrogen)
