Which of the following glands regulates the release of the hormone testosterone?

a: Receptor - Receptors are proteins that bind to signaling molecules (ligands) outside the cell and initiate cellular responses but do not typically facilitate ion movement.

b. Channel-Integral membrane proteins called ion channels create pores in the cell membrane, allowing specific ions to pass through, thus facilitating ion movement into or out of the cell.

c: Ligand - Ligands are signaling molecules that bind to receptors, activating them, but they do not facilitate ion movement.

d: Peripheral - Peripheral proteins are found on the surface of the cell membrane but are not typically involved in creating ion channels

a. QRS wave: The ECG (electrocardiogram) measures the electrical activity of the heart. The QRS complex represents ventricular depolarization, the spread of electrical excitation through the ventricles causing them to contract.

b. P wave: The P wave represents atrial depolarization, the electrical impulse moving through the atria.

c. T wave: The T wave represents ventricular repolarization, the ventricles relaxing after contraction.

d. U wave: The U wave is a small wave of uncertain origin, not related to ventricular depolarization.