Erythropoietin is secreted in response to hypoxia. It produces a negative feedback loop that raises the oxygen concentration of the blood. Also called EPO, erythropoietin, is a glycoprotein hormone that controls red blood cell production.
erythropoietin
Tissue hypoxia (oxygen deficiency) occurs when the blood vessels in the hands, feet, and other extremities narrow in response to cold
Cytokines such as interferrons and interleukins are secreted by the T cell in response to antigen. These chemicals are also secreted by B cells, dendrictic cells and natural killer cells. These chemicals are signalling agents that modulate (or properly control) the immune response
False
insulin
yes hormones can be secreted in response to external stimuli. the bast example is adrenal hormone. whenever you are afraid of some external causes it gets released
IgM.
Insulin.
IgM is the antibody first secreted during primary response
insulin is secreted in response to high blood sugar.
Cholecystokinin.
secreted