7__ (a) An post-synaptic potential is stimulated at the postsynaptic membrane and impulse travels down dendrite towards axon hillock. 2 __6___ (b) An enzyme cleaves the neurotransmitter substance and clears out the synaptic cleft. 3 ___1__ (c) Action potential reaches end of axon. 4 ___4__ (d) Impulse stimulates synaptic vesicles to move to presynaptic membrane. 5 ___2__ (e) Neurotransmitter substance diffuses across the cleft. 6 ___3__ (f) Neurotransmitter substance fits into receptor sites on postsynaptic membrane.

Hormones are chemical molecules produced by endocrine glands. one such endocrine gland is the thyroid gland, which synthesizes the thyroid hormone, which in turn affects the heart muscles. which two statements describe the probable reason for the function of the hormone? the cells in the heart have specific receptors that allow for the intake of hormones. the heart and the endocrine glands have the exact same types of cells. all cells make the same types of hormones. thyroid hormones show their effect on the heart by means of specialized cells. thyroid cells and cardiac cells have different dna.