Answer:
The correct answer is a. can be activated by the release of epinephrine.
Explanation:
Epinephrine is a hormone and neurotransmitter naturally secreted by the body through the adrenal glands, synthesized and stored in the adrenal medulla and released into the systemic circulation. Epinephrine is a non-selective adrenergic agonist, stimulating alpha1-, alpha2, beta1, and beta2-adrenergic receptors. The systemic actions of catecholamines are mediated by the binding of these compounds to plasma membrane receptors, of the GPCR type widely distributed throughout the body and known as adrenergic receptors, which are activated by the catecholamines adrenaline (epinephrine) and noradrenaline . These receptors cause different effects depending on the G protein subtypes to which they are associated and the signal transduction mechanism linked to the specific G protein.
the y axis would just be the number or points he got
