The part of the nervous system that allows the brain to regulate digestion, heart rate, and respiration without our conscious attention is the?

The correct answer is Autonomic Nervous System

Explanation:

The autonomic nervous system are mainly involuntary i.e not under conscious control.

Also, it connects the central nervous system with the following:

- glands that regulate digestion

- smooth muscles that regulate respiration and the breathing process.

- cardiac muscles of the heart that regulate heart rate.

answer; a muscle cell, another neuron and a of the above