Blood vessels are connected to nerve fibers which are regulated by the nervous system. When innervated they respond by doing what?

When blood vessels are innervated they respond by contracting and relaxing their muscle wall, as a result of the activity of the autonomic nervous system.

Explanation:

The nerves that are responsible for the innervation of the blood vessels are called nervi vasorum, and are composed of nerve fibers of the sympathetic and parasympathetic nervous systems.

The innervation of the blood vessels specifically acts on the muscular wall of the vessel, so it contracts or relaxes depending on the activity of the nervous system:

The action of the autonomic nervous system has an effect on blood pressure, being a determinant of normal or pathological behavior of the arteries.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.