Introduction Flashcards
(25 cards)
Are lipid tails hydrophilic?
No
Define molarity
Concentration of a substance in 1 L solution
Define osmolarity
Concentration of PARTICLES in 1 L solution
What is the fluid content of:
- Total body water
- Intracellular fluid
- Extra cellular fluid
- Plasma
- Interstitial fluid
- 42
- 28
- 14
- 3
- 11
Define isotonic solution
Cells neither swell nor shrink when exposed to the solution
What would an iso osmotic solution look like?
Water would flow into the cell but solutes can’t cross the membrane.
What is the difference between a hypotonic and hypertonic solution?
Hypotonic - greater concentration of solutes in the cell
Hypertonic - greater concentration of solutes outside of the cell
Exercise associated hypoatriema
Cells swell and push up against skull
Treat by ^Na which draws the H2O out (increase in urination)
Passive transport
- DOWN electrochemical gradient
- Simple diffusion (through phospholipid bilayer)
- Facilitated diffusion (carriers/channels)
Active transport
- AGAINST electrochemical gradient
- Primary - pumps use ATP
- Secondary - carriers
How is the electrochemical gradient determined?
Determined by BOTH the chemical and electrical driving forces
What does electrical driving force depend on?
Concentration AND charge
What does chemical driving force depend on?
Concentration
Which 4 ions/molecules are of greater concentration OUTSIDE the cell?
Na+
Ca2+
Cl-
HCO3-
Which 5 ions/molecules are of greater concentration INSIDE the cell?
K+ Amino acids Protein Phosphate HCO3-
Simple diffusion
Movement of a solute down a concentration gradient
What is the rate of simple diffusion
Area/distance
Also dependent on permeability
What is a key feature of facilitated diffusion
It reaches a maximum
It also moves down the electrochemical gradient
What do primary and secondary active transport have in common?
Both travel against electrochemical gradient
Name the type of transport:
Na and K pump moves both ions against the electrochemical gradient
Primary active transport
Name the type of transport
Movement of amino acids from low to high concentration and Na down electrochemical gradient via a symporter
Secondary active transport (cotransport)
How is plasma osmolarity regulated?
- When it rises, error signal increases.
- Regulatory mechanism activated.
- Plasma osmolarity decreases and error signal decreases
What type of feedback does homeostasis involve
Negative
Fill in the blanks on the Nervous System:
Message = _____________
Travels in = _____________
Target = _______________
Neurotransmitters
Synapse
Neutrons, muscle and glands