Excessive secretion of aldosterone causes which of the following responses?

A. Peristalsis, the movement of food through the digestive tract, is inhibited by sympathetic stimulation. The "fight-or-flight" response prioritizes immediate physical needs over digestion, decreasing peristalsis.

B. Bladder tone decreases with sympathetic stimulation. The sympathetic nervous system causes the bladder to relax, inhibiting urination in stressful situations.

C. Heart rate increases with sympathetic stimulation. The sympathetic nervous system activates the "fight-or-flight" response, which includes increasing heart rate to supply more oxygen and nutrients to muscles.

D. Saliva production decreases with sympathetic stimulation. During stress or danger, the body reduces non-essential activities like salivation to focus on more critical survival functions.

A. T-helper cells (CD4+ cells) play a crucial role in initiating and coordinating the immune response. They stimulate the activation of B-cells to produce antibodies and help activate cytotoxic T-cells to target infected cells.

B. The first line of defense against infection is provided by physical barriers like the skin, mucous membranes, and innate immune responses, not by T-helper cells.

C. While T-helper cells can activate macrophages indirectly by releasing cytokines, their primary role is in helping to activate other immune cells like B-cells and cytotoxic T-cells, rather than directly activating macrophages.

D. T-helper cells are not directly involved in minimizing cell damage caused by T-cells. That role is more closely related to regulatory T-cells (Tregs) that help maintain immune tolerance and prevent excessive immune responses.