synaptic cleft.
Neuromuscular junction or neuromuscular synapse
A small narrow waterway between two pieces of land is called a strait.
It is a narrow channel of water passing between 2 bodies of land.
It varies by the type of cells involved (for example, a typical synapse from a pyramidal cell in motor cortex to a spinal cord alpha-motorneuron is not the same size as a synapse from that alpha-motorneuron onto a muscle fibre). But as one example, these 1950s papers examining prototypical synapses with an electron microscope (see related links) found that the presynaptic and postsynaptic membranes were separated by about 100-200 angstroms (10-20 nm); they contain synaptic vesicles that are 200-500 angstroms (20-50 nm) in diameter. In Plate 10 of the second of these articles (on invertebrates), the synapse labelled Y has a contact area that is maybe 0.4 micrometres (400 nm) in length in this electron microscope cross-section (so if this were a cut through the middle of a circular synapse, that'd imply a synaptic area of just over one square micrometre - but this is quite variable.
It is called an isthmus.
Synapse is a narrow gap containing communicating junction between two neurons where an axon terminal comes near contact with dendrite terminal of next neuron. A narrow fluid filled space, called synaptic cleft, occurs between the two.As the impulse reaches the presynaptic knob, it stimulates release of neurotransmitter into the cleft.
Neuromuscular junction or neuromuscular synapse
This is the junction between two neurons. At the one end you have the pre-synaptic membrane - the terminal end of the previous neuron, the pre-synaptic neuron - and on the other side you have the post-synaptic membrane, part of the post-synaptic neuron. Action potentials typically cross the cleft by the use of neurotransmitters. Examples include ACh (Acetyl Choline), often used in the synaptic clefts of parasympathetic neurons.
A long or flat narrow muscle :)
Wide grip pull-ups primarily target the outer back muscles and shoulders, while narrow grip pull-ups focus more on the inner back muscles and biceps. Wide grip pull-ups are more effective for overall upper body strength and muscle activation, while narrow grip pull-ups are better for targeting specific muscle groups.
tendon
An isthmus is a narrow body of water between two lands.
No, the Straight of Gibraltar is a narrow strait between Europe and Africa.
A "spot" is more narrow than a "narrow flood".
Tendons connect muscles to bone.
extensor digiti minimi
isthmus**fjordA narrow inlet is a ria.