問題一覧
1
Which mechanisms can reduce the cytosolic Ca concentration?
PMCA, Na/Ca exchanger of plasma membrane, Endoplasmic Ca pump (SERCA)
2
TRUE
The calmldulin is able to bind Ca2 ions., Ca pump is required to transport Ca ions into the ER when the cytosolic Ca level is restored after a Ca signal.
3
Which is responsible for the increase of the Ca in the cytosol.
Voltage gated Ca channel in plasma membrane, Ryanodine receptor, IP3 receptor
4
Equilibrium potential of K
-95mV
5
Which conditions can result in hyperpolarization?
Increase of K permeability of pm., Decrease in extracellular K
6
TRUE
electrochemical equilibrium of an ion means that no net flow of that ion will occur across the membrane., Cell depolarization can be induced by elevation of EC K ion concentration., The equilibrium potential for Na ions can be +60 mV in nerve cells.
7
The equilibrium potential of K ions.
depends on the concentrations of K ions at the 2 sides of the membrane., is usually close to the resting membrane potential.
8
TRUE about resting membrane potential.
It is around -90mV in skeletal muscle fibers., It is basically determined by the diffusion potential of K ions., Na K pump contributes to its maintainancce.
9
Increasing extracellular K ions…
Decrease the K ion flow out form the cells., Depolarizes the membrane.
10
TRUE
Electochemical equilibrium of an ion means that no net flow of that ion will occur across the membrane., Cell hyperpolarization can be induced by the inflow of Cl ions., The equilibrium potential for Ca ions is +120mV in nerve cells.
11
Which is responsible for the resting membrane potential of a human neuron?
Different concentration of ions on the 2 sides of the plasma membrane., Different permability of the membrane for ions., Na+/K+ ATPase, Diffsuon potential
12
Resting membrane potential of skeletal muscle cells.
-90mV
13
Resting membrane potential of neurons.
-70mV
14
Equilibrium potential of Na+
+60mV
15
Equilibrium potential of K+
-95mV
16
Equilibrium potential of Ca2+
+120mV
17
Increasing extracellular K+ ions...
depolarizes the membrane.
18
Which is common property of the AP of a neuron?
Lidocain can inhibit its generation., Self-reinforcing., Afterhyperpolarization requires gated K+ channels., It lasts for a few milliseconds.
19
What conditions can lead to the generation of an AP?
increased conductance of Na+, activation of ionotripic glutamate receptors
20
True for the electronic potential
It is an analog signal., It can be de- or hyperpolatization,
21
True for electroronic potentials:
Both EPSP and IPSP belong to them.
22
TRUE about voltage dependent K+ channels of axons.
They do not show inactivation., They are responsible for the repolarization phase of the AP., Their activation threshold is around -50mV.
23
The action potential of skeletal muscle
spreads inward to all parts of the muscle via the T-tubules., is essential for the contraction.
24
TRUE about voltage-dependent Na+ channels!
They have an inactivation phase., They can be rapidly activated., They are responsible for the depolarization phase of the AP in nerve.
25
Permability of Na+ increases
depolarization
26
Intracellular K+ decreases
depolarization
27
Extracellular K+ increases
depolarization
28
Extracellular K decreases
hyperpolarization
29
Permability of K+ increases
hyperpolarization
30
TRUE aout the skeletal muscle.
The DHP-receptors are located in the plamsa membrane.
31
During skeletal muscle contraction;
cross bridges are formed bw myosin and actin., the myofilaments do not change their length.
32
TRUE about single-unit smotth muscle cells.
there are a lot of gap juctions bw them., pacemaker cells can cause AP without any innervation., the smooth cells in the small intestines belong to this group.
33
Smooth muscle relaxation can be induced directly by...
activation of ANP receptors, activation of B adrenergic receptors, NO
34
Gap junctions
35
Which increase of cytoplasmic Ca level in smooth muscle cells.
36
TRUE for If channel
it is responsible for the pacemaker potential., this is a non-selective monovalent cation channel, it is gated by cyclic nucleotides, the SA node contains the most If channels
37
TRUE for the smooth muscle contraction:
The phosphorylation of the myosin light chain increases its ATP-ase activity., Increase of the myosin light chain phosphotase activity promotes relaxation., Ach can induce smooth muscle contraction.
38
TRUE statements about single-unit smooth cells.
can function in the absence of innervation., part of the vascular smooth muscle cells belong to the single unit smooth muscle cells., smooth muscle cells are electrically coupled.
39
Gap junctions
Can be found in smooth muscle cells.
40
TRUE about the sympathetic nervous system.
The neurotransmitter of the sympathetic ganglion is Ach., The preganglionic neurons are located in the thoracolumbar segments of the spinal cord., Generally, both preganglionic and postganglionic fibers are long.
41
TRUE
Glutamare is the neurotransmitter in the majority of excitatory synapses in the CNS., Neurotransmitters can be taken into the synaptic terminal.
42
Which mechanisms elicit IPSP?
GABA on GABAA receptors.
43
Which mechanisms elicit EPSP?
Ach on nicotinic Ach receptors., Glutamate on AMPA receptors., Glutamate on NMDA receptors.
44
Which is TRUE about sympathetic autonomi neuron system?
The neurotransmitter released from the terminal of the preganglionic neuron is mostly Ach.
45
Which is the nicotinic Ach receptors?
Na ions enter the cell.
46
TRUE about Ach in the neuromuscular junction:
The Ach is not taken back up into the motor nerve terminal., Binding of Ach causes inward Na current., Action of Ach is terminated by Achesterase., Binding of Ach causes transient depolarization.
47
TRUE for electrical potential;
It is an analog siganl., It can be de- or hyperpolarizaiton.
48
TRUE about the neuromuscular junction:
AP of an α motor nerve always causes the contraction of the innervated muscle cell., The amplitude of end plate potential(EPP) always reches the threshold of the voltage gated Na channels., The neurotransmitter is cleaved in synaptic cleft., AP of an α motor nerve always causes AP on the innervated muscle cell.
49
Which is common property of the AP of a neuron?
TXX can inhibit its generation., Self-reinforcing, After hyperpolarization requires voltage gated K+ channels.
50
EPSP will be generated by:
Stimulation of NMDA receptors., Stimulation of AMPA receptors.
51
TRUE
Glutamate is the neurotransmitter in the vast majority of excitatory synapses in the CNS., Neurotransmitters can be taken into the synaptic terminal.
52
Which has slower conduction velocity than 200m/s?
A alpha fibers, C fibers, A gamma fibers, B fibers, A beta fibers
53
TRUE for the smooth muscle?
Phosphorylation of a myosin light chain is required for the interaction of myosin with actin., Contraction can occur via hormonal stimuli without changing Em, The activation of the myosin phosphatase will lead to relaxation.
54
Which enhance smooth muscle contraction?
Agonist binding of alpha1 adrenergic receptors of the smooth muscle cells., Opening of Ca++ channels in the sarcolemma.
55
Which elicit EPSP?
Glutamate on NMDA receptors., Opening of LG non-selective cation channels., Glu on AMPA receptors.
56
Which elicit EPSP?
Glu on AMPA receptors., Opening of nAch receptor.
57
Which is TRUE about sympathetic autonomic system?
The postganglioninc fibers are long., Sympathetic activation can result in both smooth muscle contraction and relaxation.