The hormone that increases the heart rate and blood pressure in stress is: MCQ with Answer and Explanation

Explanation:
The thymus is a lobulated lymphoid organ located in the upper part of the thoracic cavity, near the heart. It is most prominent and active during childhood and begins to atrophy (involute) after puberty. Its primary function is to provide a microenvironment for the differentiation, selection, and maturation of T-lymphocytes (T cells), which are crucial for cell-mediated immunity. The thymus also secretes hormones like thymosin, which aid in T-cell development.

Explanation:
Vitamin A is a fat-soluble vitamin stored primarily in the liver, and excess can lead to toxicity. The B-complex vitamins are water-soluble and generally not stored in the body in significant amounts. Fat-soluble vitamins (A, D, E, K) are stored in body fat and liver, making excess Vitamin D difficult to excrete, potentially causing hypervitaminosis D. Thus, statements 1 and 2 are correct.

Explanation:
Vitamin K and some B vitamins (like biotin) are synthesized by the normal microflora of the large intestine. However, the amount may be insufficient to meet total needs. Vitamin A, C, and D must be obtained from diet or sunlight. Gut bacteria contribute to vitamin K for clotting factors.