The majority of the synapses are…….
a) electrical synapses
b) chemical synapses
c) physical synapses
d) both a and b
Explanation Chemical synapses are connections between two neurons or between a neuron and a non-neuronal cell (muscle cell, glandular cell, sensory cell).
In chemical impulses, the cells are separated by a gap, the synaptic cleft of only……..nm.
a) 20
b) 2.0
c) 0.2
d) 0.02
Which of the following chemical messenger are responsible for the action potential in chemical impulses?
a) neurotransmitter
b) carbohydrate
c) lipids and proteins
d) ions
Explanation Neurotransmitters are chemical messengers that your body can't function without
The
axon terminals of which neurons have expanded tips called synaptic knob?
a) pre-synaptic neuron
b) post synaptic neuron
c) both a and b
d) none of these
Explanation A presynaptic neuron is a neuron (nerve cell) that fires the neurotransmitter as a result of an action potential entering its axon terminal.
How many molecules of neurotransmitters are present synaptic vesicles?
a) 1000
b) 5000
c) 10000
d) 100,000
Explanation synaptic vesicles are numerous tiny spherical sacs in the cytoplasm of synaptic knob
The arrival of action potential at the pre synaptic terminal depolarizes the plasma membrane, opening channels of ….ions to diffuse into the synaptic knob.
a) Na+
b) K+
c) Ca2+
d) NH4+
