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

a. Cell body: The cell body is the main part of the neuron containing the nucleus and other organelles. It does not directly transmit impulses.

b. Axon: The axon is a long fiber that carries electrical impulses away from the cell body towards other neurons or muscles.

c. Synapse: A synapse is a junction between two neurons where nerve impulses are transmitted. The axon of one neuron transmits an electrical signal to the dendrite or cell body of another neuron across a small gap. Neurotransmitters are released from the presynaptic neuron and bind to receptors on the postsynaptic neuron, either exciting or inhibiting it.

d. Dendrite: Dendrites are short, branching fibers that receive signals from other neurons and transmit them towards the cell body.

a. Sodium: Correct. Sodium (Na⁺) is the primary extracellular cation and plays a crucial role in maintaining osmotic pressure and fluid balance in the body.

b. Magnesium: Magnesium (Mg²⁺) is important for many cellular functions but is not a major contributor to osmotic pressure compared to sodium.

c. Calcium: Calcium (Ca²⁺) is vital for bone health and cellular processes but does not primarily influence osmotic pressure.

d. Potassium: Potassium (K⁺) is the main intracellular cation and affects cell function, but sodium has a more significant role in osmotic pressure regulation.