Cardiac muscles are functionally similar to which of the following?

Analogy type questions:
$(1)$ Red muscle fibers / White muscle fibers have fewer mitochondria but more sarcoplasmic reticulum.
$(2)$ When nerve impulses reach the neuromuscular junction,acetic acid / acetylcholine neurotransmitter is released.

The membrane sarcolemma is found over

The belly is the ...... of a muscle.

At which site do muscle fibers receive stimulation from a motor neuron?

Cardiac muscle fibers differ from skeletal muscle fibers in that they are -