Question

Auerbach's plexus is found in
A. Below dermis and made up of muscles
B. Outer to muscularis externa and made up of nerves
C. Below muscularis interna
D. Layer of podocytes in glomerulus of kidney

Answer 1

Hint: Auerbach's plexus, also known as myenteric plexus is a group of ganglia that run through the entire gastrointestinal tract and innervate its multiple layers of smooth muscles. The nerve is sandwiched between the two layers of the muscularis externa, the inner circular muscle layer, and the outer longitudinal muscle.

Complete answer:
Auerbach plexus is one of two significant components of the enteric nervous system. It is a collection of interconnected neurons that spans from the oesophagus to the rectum. It is present in the outer to muscularis externa and made up of nerves. Structurally, axons start over 100 nm away from the smooth muscle cells they innervate. In contrast to other areas of the peripheral nervous system, they lack a clearly defined postsynaptic area and do not form neuromuscular junctions.

Excitatory and inhibitory motor neurons allow smooth muscle cells of the intestines to exist in an electrical syncytium. Control of these signals is initiated by various neurotransmitters that can produce either relaxation or contraction of these smooth muscles. Specific patterns of movement that are the result of this process create the peristalsis that transports food along the gastrointestinal tract. There are numerous neurotransmitters involved in this process. The most important ones responsible for intestinal relaxation are vasoactive intestinal peptide (VIP), nitric oxide, pituitary adenylate cyclase-activating peptide, and purine.

Hence, the correct answer is option B.

Note: Auerbach's plexus or myenteric plexus is a part of the enteric nervous system that is located between the longitudinal and circular layers of muscularis externa in the gastrointestinal tract. It is mainly made up of sensory nerves.