A follicle is the tubelike structure from which hair grows.
Esophagus
Smooth Muscles line the walls of tubelike structure such as the gastrointestinal tract, the urinary system, the blood vessels and the bronchi of the lungs.
I think you might be thinking of the esophagus.
Afferent neurons
Ureter. The urethra connects the bladder to the outside world.
Structure Unipolar Bipolar Multipolar AND FUNCTION sensory or afferent neurons Motor or efferent neurons
The space within a tube-like structure is called a lumen. Parts of the body with lumens include veins and arteries.
Neurons
Dendrites
h
Myelin Sheath is the structure that insulates most part of neuron