Most effector organs receive dual innervation, but some (e.g., adrenal medulla, sweat glands, pilomotor muscles, and many blood vessels) are innervated by only the sympathetic nervous system.
Moreover, what is innervation of the heart?
Atrial muscle is also innervated by vagal efferents, whereas the ventricular myocardium is only sparsely innervated by vagal efferents. Sympathetic efferent nerves are present throughout the atria (especially in the SA node) and ventricles, including the conduction system of the heart.
How does the autonomic nervous system innervate the lens?
The parasympathetic fibers, the visceral motor component (VM), of the oculomotor nerve innervate smooth muscles in the eye that cause the pupil to constrict and the lens of the eye to bulge—actions that allow focusing on close objects in the field of vision.
Do blood vessels have parasympathetic innervation?
Most blood vessels in the body do not have parasympathetic innervation. However, parasympathetic nerves do innervate salivary glands, gastrointestinal glands, and genital erectile tissue where they cause vasodilation.