(2) When people are stimulated by cold, the corresponding nerve impulses are transmitted to the hypothalamus, and some cells in the hypothalamus can synthesize and secrete thyrotropin-releasing hormone, which eventually urges the thyroid gland to synthesize and secrete more thyroid hormones; When it increases to a certain extent, it can inhibit the secretion of hypothalamus and pituitary gland, which is called feedback regulation.
(3) When the antigen invades the human body, the antigen recognition receptor on the surface of B cell binds to the antigen and the cell is activated. The differentiated plasma cells produce a large number of antibodies and secrete them into the blood, which combine with antigens to form precipitates or cell clusters, and then are completely hydrolyzed by phagocytes.
So the answer is:
(1) pituitary? raise
(2) Thyroid stimulating hormone releasing hormone? Hypothalamus and pituitary? feedback
(3)B？ Plasma (effector B cells) phagocytosis