Exam1 Flashcards
Why do we care about osmole?
Because the greater the osmoles the greater tho osmotic pressure
What is osmolarity?
It is osmoles per liter Osm/L
What is an equivalent?
It is the amount of charged solute in solution ex: CaCl2= 2 Eq of Ca and 2 Eg of CL
What are the major ions in ECF?
Major cation= Na+
Major anion= Cl- and HCO3-
What does ionized calcium mean?
It means that it is free calcium, not bound and it is the active form that can interact with other substances
Acid base balance is managed by?
Managing how much calcium is bound and how much is free (participates in reactions)
What is the perfect osmolarity in animal species?
290-300 mOsm/L
What are the major ions in ICF?
Cation= K+
Major anions= organic phosphates and proteins
What are the major ions in ICF?
Cation= K+
Major anions= organic phosphates and proteins
The most common mechanism of transport in cells is?
Sodium potassium pump
Sodium goes out of the cell
Potassium goes inside the cell
Which direction Ca+ goes?
Out of the cell
Na+ difference allows what?
Upstroke of action potential in nerve and muscle cells
What allows the membrane to be permeable to lipid-solubles (e.g., CO2, steroid hormones, O2, FA)
Glycolipids, lipids, and proteins.
Simple and facilitated diffusion is?
Using a protein to get across, the substance can get across (lipid soluble)
Moving into a gradient of higher concentration we use?
ATP
Primary (directly uses energy) or secondary transport (indirectly uses energy)
Simple diffusion
moves to less concentration
What is the driving force?
Concentration gradient
Partition coefficient
The greater the solutes, solubility in oil the higher the partition coefficient and more easily can diffuse
Diffusion coefficient
Has to do more with the radius of sollute and viscosity. Small solute in non-viscous solution more easily can move across the cell membrane
Surface area
The more surface area you have the higher the diffusion rate (more chances to get across)
What are the consequences of charge when an ion is diffusing?
Positive to where a lot positive already there, then the ion is going to slow down.
A diffusion potential can be created when ion is going into less concentration of same
Does facilitated diffusion required energy?
No, it does not require an input of energy
However, there is a limit number of carriers. When the concentration is
Why is saturation important?
The rate of transport is going to be highest at lower solute concentrations. There are more binding sites when carrier proteins are limited. Maximum is reached.
Stereospecificity
Biding sites for solute on carries proteins are specific
Simple diffusion
It has to be a lipid bc it is lipid bilayer membrane
Facilitated diffusion
It has to be water soluble
Rate of transport is highest when?
At lower solute concentrations
Na+/K+ ATPase pump
Moved against a concentration gradient
What are cardiac glycosides?
Substances that can inhibit the transport of sodium potassium pump
Ca2+ ATPase pump
PMCA: plasma-membrane
SERCA: Sarcoplasmatic and endoplasmatic
H+/K+ ATPase pump
Hydrogen pumped into the stomach
Secondary active transport
It utilizes the sodium potassium gradient already crates by the pump
Types of secondary transport
Co-transport (symport): all solutes transported in same direction
Na+/glucose (SGLT1), Na+/amino acid, Na+/K-/CL2 transporters
-Counter-transport (antiport)
Solutes move in opposite direction
What is osmosis?
Flow of water across semipermeable membrane due to differences in solute concentration.
It occurs due to pressure differences caused by the solutes that can’t cross the membrane
When salt is ingested where does it go first?
ICF (blood cells)
What is hydrostatic pressure?
Due to pressure of the fluid itself required to stop the osmotic pressure
Hydrostatic pressure allows what to leave the blood?
It allows solutes to leave the blood
What is oncotic pressure?
It is osmotic pressure if referring to the tissues and cells
Isosmotic means?
Solutions that have equal concentration of solutes, same osmolality
Hyperosmotic means?
Solution has higher osmolality (higher solute)
Hypoosmotic means?
Lower concentration of solute, osmolality
Tonicity is used for?
Measure the response of cells to solution environment
Tonicity is used for?
Measure the response of cells to solution environment
Oncotic pressure is related to?
Concentration of protein in the blood
If resistance was zero what would happen?
There would not be any potential because anything times zero equals zero
If resistance go up (blood flow potential) what happens to potentials of fluid movement?
Current decreases
Absolute refractory period
Period where the action potential can not be stimulated and cause another AP
Relative refractory period
depends on time and stress, the stimulus has to be abnormally high to activate again
Active potential (AP) is characteristic of?
Each cell’s and they have an specific size/shape given the cell type
Where does the stimulus AP begin?
Close to the cell body and it spreads down to the axon of the cell via local currents
Describe Bipolar neurons
The signal flows only one way
The input area is the dendrite the output area is the axon
Peripheral nerves axon is where the signal
Produces motor reaction
Pseudo-unipola neurons
Are more common, example is a sensory neuron
Multipolar neuron ex: purkinje cell
Takes a lot of sensory information, so it has a large amount of dendrites
What is the electrical synapse?
The connection area where current flows between cell via GAP JUNCTIONS
Describe the chemical synapse?
Gap between presynaptic and postsynaptic cell- via synaptic cleft
What is the sequence of events during a chemical synapse?
- AP arrives at the presynaptic axon
- Voltage-gated calcium ion channels open
- Ca2+ enters the presynaptic cell
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