Exam 2 Flashcards
physiology
definition & etymology
Physio = nature
Logy = study of
Science of body functions; how body parts work
what are cells made of?
general, specific
organelles
- cytoplasm
- cell membrane
organelles
Intracellular structures that perform specific biochemical functions
cytoplasm
Internal structures (organelles) + intracellular fluid (cytosol)
cell membrane
- Cell border
- Separates cytoplasm and external env’t of cell
- Semipermeable
- organization = phospholipid bilayer
phospholipid bilayer components
- hydrophilic head
- hydrophobic tail
cellular environment: fluid compartments
- intracellular fluid ⇒ within cell (40% TBW)
- extracellular fluid ⇒ plasma + interstitial fluid (20% TBW)
– Ex. lymph
– Interstitial fluid → occupies space bet. cells
contents of fluid compartments
- water
- ions & electrolytes
water
- 60% TBW of an average 70kg adult man = water (42L)
- Percentages slightly differ bet. males & females
ions & electrolytes
-
Ions = particles w/ net charge
1. ANIONS → negative ion (Cl, HCO3-, phosphates, proteins)
2. CATIONS → positive ion (Na+, K,)
3. ELECTROLYTES → ions from substances dissolved in water
general principles of electrochemical gradients
- concentration gradient
- electrical gradient
- electrochemical gradient
concentration gradient
High to low conc.
electrochemical gradient
CHARGED PARTICLES flow from positively charged to negatively charged area
electrochemical gradient
definition, example
- Combined effect of conc. & electrical gradient
- Continuous change in charge
- ex. sodium-potassium pump
sodium-potassium pump
Extracellular fluid
* More positive than ICF
* Sodium in
Intracellular fluid
* More negative than ECF
* Potassium movement
– Conc. G ⇒ ICF to ECF
– Electric G. ⇒ ECF to ICF
