Question

thromboxane is a chemical mediator released by platelets. thromboxane promotes the aggregation of platelets which results in platelet plug formation during hemostasis. thromboxane would therefore be classified as a/an
multiple choice
autocrine chemical messenger
paracrine chemical messenger
endorphin
enkephalin
neurotransmitter

Explanation:

Autocrine chemical messengers act on the same cell that secretes them. Platelets release thromboxane, and thromboxane acts on platelets (the same cells that released it) to promote aggregation. Paracrine messengers act on nearby cells, endorphins are related to pain - relief and are not involved in platelet aggregation, enkephalins are also related to pain - modulation, and neurotransmitters are for nerve - to - nerve or nerve - to - target communication (not relevant here).

Answer:

autocrine chemical messenger