PMCOL 343- CV I TEST WITH
COMPLETE SOLUTION
What is Ca+ important for in the body - Answer Contraction, excitation, and secretion
Does calcium exist in higher levels outside of the cell or inside the cell - Answer Higher
levels outside
What are the 2 main storage organelles for calcium - Answer The endoplasmic /
sarcoplasmic reticulum and mitochondria
Describe how voltage gated calcium channels regulate the amount of ca entering the
cell - Answer These channels open when depolarized, and Ca++ flows into the cell via
the electrochemical gradient
Describe how ligand gated calcium channels regulate the amount of ca entering the cell
- Answer These channels open via the presence of an agonist, and Ca++ flows in
Describe how store operated calcium channels regulate the amount of ca entering the
cell - Answer These channels open when intracellular calcium stores are depleted, and
Ca++ flows in
Describe how GPCRs regulate the amount of ca entering the cell - Answer These
channels, under stimulation of an agonist, activate IP3 signalling, which interacts with
the IP3 R, increasing Ca++ from the ER
Describe how ryanodine receptors regulate the amount of ca entering the cell - Answer
When stimulated, they release Ca++ from ER storage
There are several different types of voltage gated Ca++ channels, L,N,P,R, and T, which
are involved in NT release - Answer N-type and P-type
There are several different types of voltage gated Ca++ channels, L,N,P,R, and T, which
are involved in heart and smooth muscle - Answer L-type
Name 3 drugs that inhibit voltage gated Ca++ channels - Answer Verapamil, diltiazem,
nifedipine
What class of drugs is nifedipine - Answer A dihydropyridine (DHPs)
Out of the three previously listed drugs, which are used to treat hypertension - Answer
Nifedipine (DHPs)
Out of the three previously listed drugs, which are used to treat angina and
supraventricular arrhythmias - Answer Verapamil and diltiazem
, What ligand gated channels cause glutamate toxicity - Answer NMDA type Ca++
channels
What is considered to be the only true ligand gated ion channel in smooth muscle -
Answer ATP-gated P2X channels
What process occurs when intracellular Ca++ stores are depleted - Answer Causes
STIM1 to accumulate at locations where the ER is close to the plasma membrane
The ER / STIM1 interaction with what channel allows for Ca++ to enter the ER - Answer
Ca++ released activated Ca++ (CRAC channels)
Describe the function of the plasma membrane pump - Answer Keeps the cytoplasmic
Ca++ low by pumping it out of the cell
What is necessary for the function of the plasma membrane pump - Answer ATP energy
needed to transport Ca++ against concentration gradients
Describe the function of the SERCA pump - Answer Keeps cytoplasmic Ca++ low by
pumping it into the ER / SR (ATP needed)
What drugs blocks the reuptake of Ca++ into the ER - Answer Thapsigargin
What would be the result of blocking the ATP SERCA pump - Answer Promotes cellular
contraction (higher Ca++ in the cytosol)
Describe the mechanism of action that allows the NCX to transport Ca++ out of the cell -
Answer Uses the energy from the Na+ gradient (high Na+ outside, low Na+ inside) to
bring Na+ in, and pump out Ca++
The NCX brings in 3 Na+ for every 1 Ca++ pumped out, what does this result in - Answer
Makes the cell more positive (electrogenic), which can cause depolarization of the cell
What occurs when the NCX brings in too much Na+, reducing the Na+ gradient - Answer
NCX goes into "reverse mode activity," which can result in accumulation of Ca++ in the
cell
What type of receptor is the IP3R - Answer A ligand gated ion channel (in the SR / ER)
Describe why Gq linked receptors elevate Ca++ (2) - Answer PIP2 breakdown into IP3
and DAG; DAG can induce Ca++ release via PKC actions, and IP3 can cause Ca++
release from the ER / SR
COMPLETE SOLUTION
What is Ca+ important for in the body - Answer Contraction, excitation, and secretion
Does calcium exist in higher levels outside of the cell or inside the cell - Answer Higher
levels outside
What are the 2 main storage organelles for calcium - Answer The endoplasmic /
sarcoplasmic reticulum and mitochondria
Describe how voltage gated calcium channels regulate the amount of ca entering the
cell - Answer These channels open when depolarized, and Ca++ flows into the cell via
the electrochemical gradient
Describe how ligand gated calcium channels regulate the amount of ca entering the cell
- Answer These channels open via the presence of an agonist, and Ca++ flows in
Describe how store operated calcium channels regulate the amount of ca entering the
cell - Answer These channels open when intracellular calcium stores are depleted, and
Ca++ flows in
Describe how GPCRs regulate the amount of ca entering the cell - Answer These
channels, under stimulation of an agonist, activate IP3 signalling, which interacts with
the IP3 R, increasing Ca++ from the ER
Describe how ryanodine receptors regulate the amount of ca entering the cell - Answer
When stimulated, they release Ca++ from ER storage
There are several different types of voltage gated Ca++ channels, L,N,P,R, and T, which
are involved in NT release - Answer N-type and P-type
There are several different types of voltage gated Ca++ channels, L,N,P,R, and T, which
are involved in heart and smooth muscle - Answer L-type
Name 3 drugs that inhibit voltage gated Ca++ channels - Answer Verapamil, diltiazem,
nifedipine
What class of drugs is nifedipine - Answer A dihydropyridine (DHPs)
Out of the three previously listed drugs, which are used to treat hypertension - Answer
Nifedipine (DHPs)
Out of the three previously listed drugs, which are used to treat angina and
supraventricular arrhythmias - Answer Verapamil and diltiazem
, What ligand gated channels cause glutamate toxicity - Answer NMDA type Ca++
channels
What is considered to be the only true ligand gated ion channel in smooth muscle -
Answer ATP-gated P2X channels
What process occurs when intracellular Ca++ stores are depleted - Answer Causes
STIM1 to accumulate at locations where the ER is close to the plasma membrane
The ER / STIM1 interaction with what channel allows for Ca++ to enter the ER - Answer
Ca++ released activated Ca++ (CRAC channels)
Describe the function of the plasma membrane pump - Answer Keeps the cytoplasmic
Ca++ low by pumping it out of the cell
What is necessary for the function of the plasma membrane pump - Answer ATP energy
needed to transport Ca++ against concentration gradients
Describe the function of the SERCA pump - Answer Keeps cytoplasmic Ca++ low by
pumping it into the ER / SR (ATP needed)
What drugs blocks the reuptake of Ca++ into the ER - Answer Thapsigargin
What would be the result of blocking the ATP SERCA pump - Answer Promotes cellular
contraction (higher Ca++ in the cytosol)
Describe the mechanism of action that allows the NCX to transport Ca++ out of the cell -
Answer Uses the energy from the Na+ gradient (high Na+ outside, low Na+ inside) to
bring Na+ in, and pump out Ca++
The NCX brings in 3 Na+ for every 1 Ca++ pumped out, what does this result in - Answer
Makes the cell more positive (electrogenic), which can cause depolarization of the cell
What occurs when the NCX brings in too much Na+, reducing the Na+ gradient - Answer
NCX goes into "reverse mode activity," which can result in accumulation of Ca++ in the
cell
What type of receptor is the IP3R - Answer A ligand gated ion channel (in the SR / ER)
Describe why Gq linked receptors elevate Ca++ (2) - Answer PIP2 breakdown into IP3
and DAG; DAG can induce Ca++ release via PKC actions, and IP3 can cause Ca++
release from the ER / SR
