Body fluids and membrane transport Flashcards
Composition of avg human body - 30yr 70kg male
18% fat
22% lean body mass - soft organs, muscle mass etc.
60% water - approx 42litres
Composition of total body water
42L of TBW =
- 25L Intracellular fluid
- 17L Extracellular fluid; 13L Interstitial Fluid (outside blood vessels, not inside cells), 3L Plasma & 1L Transcellular fluid (crossed an epithelial layer)
Examples of trancellular fluid
- Cerebrospinal fluid
- Urine
- Gastrointestinal secretions
- Sweat
- Aqueous and vitreous humours (eye)
- Synovial fluid (joints)
def of osmolality
the number of osmoles of a solute in a kg of solvent - ie attractiveness of a solution to water
effect on osmolality when fluid moves through intracellular and cellular
remains constant
composition of electrolytes from interstitial fluid into intracellular fluid
- Na+ decreases
- thus Cl- decreases
- K+ increases
- proteins increase
- osmolality remains constant
def of transcellular fluid
bodily fluid found in chambers created by linings of epithelial cells
def of interstitial fluid
fluid found in spaces surrounding the cells (stuff between blood vessels and cells)
def of extracellular
fluid outside of the cells (interstitial fluid, plasma, transcellular)
def of intracellular
fluid within the cells
three types of membrane proteins
- channels
- carriers
- pumps
why aren’t there many pumps
- require energy
- typically used to provide a gradient that allows the passive carriers to work
- more energy efficient
what types of molecules do NOT need a transporter
lipid soluble
name of carrier that transports 1 ion species in 1 direction
facilitator/uniport
name of carrier that transports 2 ion species in 1 direction
cotransporter/symport
