Which of the following elements is necessary for normal thyroid function?

A. The Bundle of His is the pathway that carries the electrical impulse from the AV node to the right and left bundle branches, which leads to the Purkinje fibers and ultimately causes the ventricles to contract.

B. The Purkinje fibers are the last component of the conduction system, responsible for rapidly transmitting the impulse to the ventricular muscle to trigger contraction, but the impulse must first travel through the Bundle of His.

C. The SA node is the natural pacemaker of the heart, initiating the electrical impulse, but the impulse does not travel to the SA node after the AV node. The SA node sends impulses to the atria first.

D. The bundle branches are part of the conduction system that transmits the electrical impulse to the Purkinje fibers. The impulse reaches the bundle branches after traveling through the Bundle of His.

A. The ejaculatory ducts are formed by the union of the vas deferens and the seminal vesicles. Seminal fluid does not enter the ejaculatory ducts directly after leaving the epididymis.

B. The prostate gland contributes fluids to seminal fluid but is not the direct next location for the fluid after leaving the epididymis.

C. The seminal vesicle produces fluid that combines with sperm to form semen, but it is not the immediate next structure after the epididymis.

D. The vas deferens is the tube that transports sperm from the epididymis to the urethra. After leaving the epididymis, seminal fluid enters the vas deferens.