Week Two A/P Flashcards
Osmotic Pressure
Osmotic pressure is greater where solute concentration is ______
Water will flow to the solution with ______ solute concentration, or in other words, the solution with ______ osmotic pressure
Water flows through the cell membrane through channels called _______
Higher
Higher, Greater
Aquaporins
Osmotic Pressure
Solution with high OP is ______
Solution with low OP is ______
_______ osmotic pressure is the pressure created by plasma proteins
[equals ___ mmHg]
Hypertonic
Hypotonic
Colloid
28 mmHg
Ion Channels
______ proteins that span the membrane when open, permitting the passage of certain ___
They are ______
Two different types of ion channels: _____-gated and _____-gated
Integral, Ions
Selective
Voltage-gated and Ligand-gated
Voltage Gated Channels
Opened or closed based on changes in ______ ______
Activation gate of the Na+ channel in nerve is opened by _______
When open, the nerve membrane is permeable to ____ (during upstroke of AP)
Inactivation gate of the Na+ channel in nerve is closed by _______
When closed, the nerve membrane is impermeable to ____ (during repolarization)
Membrane Potential
Depolarization
Na+
Repolarization
Na+
Ligand Gated Channels
Opened or closed by ______, _______ messengers, or _________
Ex: _______ receptor for Acetylcholine at motor end plate is an ion channel that opens when Ach binds to it
When open, it is permeable to ___ and ___, causing the motor end plate to depolarize
Hormones, Second Messengers, Neurotransmitters
Nicotonic
Na+ and K+
Ligand Gated Channels
______ channels are ligand-gated. These channels open when GABA binds to its receptor
When chloride channels are open, inward movement of _____ ions is allowed into the cells
Chloride
Cl-
GABA/Benzodiazepines
Binding of GABA is _____ by benzodiazepines, resulting in greater entry of ____ ions into the cell, leading to _______ (a more negative charge)
The hyperpolarization makes it more difficult to _______, and reduces neuronal excitability
Enhanced
Cl-, Hyperpolarization
Depolarize
Action Potential
Cells contain a high ___ concentration
Membrane electrical potential difference is generated from diffusion of ___ through leaky channels
Typical resting membrane potentials in neurons is ____ to ____ mV
K+
K+
-70 to -90 mV
Action Potentials
___ entry into cell causes a more _____ charge to occur within the cell
Only two cells, ______ and ______ cells can achieve the action potential spike
Conclusively, the AP process is initiated from _____ K+ channels
Na+, Positive
Neuron, Muscle
Leaky
Depolarization
Makes cell membrane potential less ______, due to movement of positively charged ____ ions into the cell
This leads to increased ________
Negative, Na+
Excitability
Repolarization
Returns the membrane back to its ______ potential
Repolarization results from the movement of positively charged ___ ions out of the cells
Resting
K+
Hyperpolarization
Makes membrane potential more _____ due to movement of negatively charged ____ ions into the cell
Decreased cell _______
Negative, Cl-
Excitability
Inward current is the flow of ______ charge into the cell. Inward current ______ the membrane potential
Outward current is the flow of _____ charge out of the cell. Outward current _______ the membrane potential
Positive, Depolarizes
Positive, Hyperpolarizes
Threshold
The membrane potential at which the action potential is ______
Resulting depolarization gives rise to upstroke of _____ _____
If net inward current is ____ than net outward current, no action potential will occur
Inevitable
Action Potential
Less
Upstroke (Depolarization)
Inward ___ movement
______ blocks these voltage sensitive Na+ channels, and abolishes action potential
No ___ entry = No depolarization
Na+
Lidocaine
Na+
Downstroke (Repolarization)
Outward __ movement
Outward flow of K+ ______ the membrane potential
K+
Hyperpolarizes
Absolute Refractory Period
Period during which another action potential cannot occur, no matter how large the ______. This is due to closure (inactivation) of ____ gates
Stimulus
Na+
Relative Refractory Period
Period during which an action potential can be elicited only if a ______ than usual stimulus is provided
The refractory period protects the cell from ____-_______, allowing a ______ period between action potentials
Larger
Over-Excitation
Recovery
Local Anesthetics
Local anesthetics are weak bases present in an ______ form (LA) and ______ form (LAH+)
______ form (LA) penetrates the cell membrane
pH is ____ inside the cells, causing more of the ______ form to produce
_____ form (LAH+) blocks the ____ channels from the inside, inhibiting conduction of pain impulses
Un-ionized, Ionized
Un-ionized
Acidic, Ionized
Ionized, Na+
Local Anesthetics
Slow the rate of _______ of the nerve action potential such that the ______ potential is not reached
Due to this, an _____ _____ cannot occur and a conduction blockade results
Depolarization, Threshold
Action Potential
Inhaled Anesthetics
(Isoflourane, Desflurane, Sevoflurane)
______ the effect of GABA
Increase entry of ___
________ of cell (makes cell less responsive and more difficult to depolarize)
Enhance
Cl-
Hyperpolarization
Hypokalemia
______ the diffusion gradient
Serum hypokalemia will cause a _____ KCL leak from the cell to the serum, creating a _______ and ______ weakness
Increases
Larger, Hyperpolarization, Muscle
Hyperkalemia
______ the diffusion gradient
AP does not occur because inactivation gates of Na+ channels are closed by _______
Without action potential, there is no _____ (muscle weakness)
No ______ is allowed to occur
Decreases
Depolarization
Contraction
Repolarization
Cardioplegic Solution
Causes rapid membrane _______
No ______ can occur due to high extracellular ___
Na+ channels are locked in an _____ state
Heart muscle is in a permanent ______ ______ period
________ is a drug that also causes rapid depolarization
Depolarization
Repolarization, K+
Inactive
Absolute Refractory
Succinylcholine
